Commit Graph

657 Commits

Author SHA1 Message Date
Dexuan Cui 433e19cf33 Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()
Commit a389fcfd2c ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")
added the proper mb(), but removed the test "prev_write_sz < pending_sz"
when making the signal decision.

As a result, the guest can signal the host unnecessarily,
and then the host can throttle the guest because the host
thinks the guest is buggy or malicious; finally the user
running stress test can perceive intermittent freeze of
the guest.

This patch brings back the test, and properly handles the
in-place consumption APIs used by NetVSC (see get_next_pkt_raw(),
put_pkt_raw() and commit_rd_index()).

Fixes: a389fcfd2c ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reported-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
Tested-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-31 10:59:48 +01:00
K. Y. Srinivasan 8e27a23631 Drivers: hv: vmbus: Cleanup hyperv_vmbus.h
Get rid of all unused definitions.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:53:34 +01:00
K. Y. Srinivasan 37e11d5c70 Drivers: hv: vmbus: Define an APIs to manage interrupt state
As part of cleaning up architecture specific code, define APIs
to manage interrupt state.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:52:49 +01:00
K. Y. Srinivasan 7297ff0ca9 Drivers: hv: vmbus: Define an API to retrieve virtual processor index
As part of cleaning up architecture specific code, define an API
to retrieve the virtual procesor index.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:52:48 +01:00
K. Y. Srinivasan 06d1d98a83 Drivers: hv: vmbus: Define APIs to manipulate the synthetic interrupt controller
As part of cleaning up architecture specific code, define APIs
to manipulate the interrupt controller state.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:51:21 +01:00
K. Y. Srinivasan 8e307bf82d Drivers: hv: vmbus: Define APIs to manipulate the event page
As part of cleaning up architecture specific code, define APIs
to manipulate the event page.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:51:21 +01:00
K. Y. Srinivasan 155e4a2f28 Drivers: hv: vmbus: Define APIs to manipulate the message page
As part of cleaning up architecture specific code, define APIs
to manipulate the message page.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:51:21 +01:00
K. Y. Srinivasan d383877db6 Drivers: hv: vmbus: Get rid of an unsused variable
The version variable while it is initialized is not used;
get rid of it.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:51:21 +01:00
K. Y. Srinivasan 305f7549c9 Drivers: hv: util: Use hv_get_current_tick() to get current tick
As part of the effort to interact with Hyper-V in an instruction set
architecture independent way, use the new API to get the current
tick.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:48:03 +01:00
K. Y. Srinivasan d5116b4091 Drivers: hv: vmbus: Restructure the clockevents code
Move the relevant code that programs the hypervisor to an architecture
specific file.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:48:03 +01:00
K. Y. Srinivasan e810e48c0c Drivers: hv: vmbus: Move the code to signal end of message
As part of the effort to separate out architecture specific code, move the
code for signaling end of message.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:48:03 +01:00
K. Y. Srinivasan 73638cddaa Drivers: hv: vmbus: Move the check for hypercall page setup
As part of the effort to separate out architecture specific code, move the
check for detecting if the hypercall page is setup.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:48:03 +01:00
K. Y. Srinivasan d058fa7e98 Drivers: hv: vmbus: Move the crash notification function
As part of the effort to separate out architecture specific code, move the
crash notification function.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:48:03 +01:00
K. Y. Srinivasan 8de8af7e08 Drivers: hv: vmbus: Move the extracting of Hypervisor version information
As part of the effort to separate out architecture specific code,
extract hypervisor version information in an architecture specific
file.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:48:03 +01:00
K. Y. Srinivasan 63ed4e0c67 Drivers: hv: vmbus: Consolidate all Hyper-V specific clocksource code
As part of the effort to separate out architecture specific code,
consolidate all Hyper-V specific clocksource code to an architecture
specific code.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-20 14:48:03 +01:00
K. Y. Srinivasan 6ab42a66d2 Drivers: hv: vmbus: Move Hypercall invocation code out of common code
As part of the effort to separate out architecture specific code, move the
hypercall invocation code to an architecture specific file.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19 11:44:55 +01:00
K. Y. Srinivasan 8730046c14 Drivers: hv vmbus: Move Hypercall page setup out of common code
As part of the effort to separate out architecture specific code, move the
hypercall page setup to an architecture specific file.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19 11:42:07 +01:00
K. Y. Srinivasan 352c962424 Drivers: hv: vmbus: Move the definition of generate_guest_id()
As part of the effort to separate out architecture specific code, move the
definition of generate_guest_id() to x86 specific header file.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19 11:42:07 +01:00
K. Y. Srinivasan 3f646ed70c Drivers: hv: vmbus: Move the definition of hv_x64_msr_hypercall_contents
As part of the effort to separate out architecture specific code, move the
definition of hv_x64_msr_hypercall_contents to x86 specific header file.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19 11:42:07 +01:00
K. Y. Srinivasan d77044d142 Drivers: hv: util: Backup: Fix a rescind processing issue
VSS may use a char device to support the communication between
the user level daemon and the driver. When the VSS channel is rescinded
we need to make sure that the char device is fully cleaned up before
we can process a new VSS offer from the host. Implement this logic.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-10 21:46:41 +01:00
K. Y. Srinivasan 20951c7535 Drivers: hv: util: Fcopy: Fix a rescind processing issue
Fcopy may use a char device to support the communication between
the user level daemon and the driver. When the Fcopy channel is rescinded
we need to make sure that the char device is fully cleaned up before
we can process a new Fcopy offer from the host. Implement this logic.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-10 21:46:41 +01:00
K. Y. Srinivasan 5a66fecbf6 Drivers: hv: util: kvp: Fix a rescind processing issue
KVP may use a char device to support the communication between
the user level daemon and the driver. When the KVP channel is rescinded
we need to make sure that the char device is fully cleaned up before
we can process a new KVP offer from the host. Implement this logic.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-10 21:46:41 +01:00
K. Y. Srinivasan ccb61f8a99 Drivers: hv: vmbus: Fix a rescind handling bug
The host can rescind a channel that has been offered to the
guest and once the channel is rescinded, the host does not
respond to any requests on that channel. Deal with the case where
the guest may be blocked waiting for a response from the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-10 21:46:41 +01:00
Vitaly Kuznetsov 523b940870 hv: make CPU offlining prevention fine-grained
Since commit e513229b4c ("Drivers: hv: vmbus: prevent cpu offlining on
newer hypervisors") cpu offlining was disabled. It is still true that we
can't offline CPUs which have VMBus channels bound to them but we may have
'free' CPUs (e.v. we booted with maxcpus= parameter and onlined CPUs after
VMBus was initialized), these CPUs may be disabled without issues.

In future, we may even allow closing CPUs which have only sub-channels
assinged to them by closing these sub-channels. All devices will continue
to work.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-10 21:46:41 +01:00
Vitaly Kuznetsov 76d36ab798 hv: switch to cpuhp state machine for synic init/cleanup
To make it possible to online/offline CPUs switch to cpuhp infrastructure
for doing hv_synic_init()/hv_synic_cleanup().

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-10 21:46:41 +01:00
K. Y. Srinivasan e7e97dd8b7 Drivers: hv: vmbus: Prevent sending data on a rescinded channel
After the channel is rescinded, the host does not read from the rescinded channel.
Fail writes to a channel that has already been rescinded. If we permit writes on a
rescinded channel, since the host will not respond we will have situations where
we will be unable to unload vmbus drivers that cannot have any outstanding requests
to the host at the point they are unoaded.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-10 21:46:41 +01:00
Vitaly Kuznetsov 56ef6718a1 hv: don't reset hv_context.tsc_page on crash
It may happen that secondary CPUs are still alive and resetting
hv_context.tsc_page will cause a consequent crash in read_hv_clock_tsc()
as we don't check for it being not NULL there. It is safe as we're not
freeing this page anyways.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-10 21:46:40 +01:00
Vitaly Kuznetsov 3c7630d350 hv: init percpu_list in hv_synic_alloc()
Initializing hv_context.percpu_list in hv_synic_alloc() helps to prevent a
crash in percpu_channel_enq() when not all CPUs were online during
initialization and it naturally belongs there.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-10 21:46:40 +01:00
Vitaly Kuznetsov 421b8f20d3 hv: allocate synic pages for all present CPUs
It may happen that not all CPUs are online when we do hv_synic_alloc() and
in case more CPUs come online later we may try accessing these allocated
structures.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-10 21:46:40 +01:00
Vitaly Kuznetsov c0bb03924f Drivers: hv: vmbus: Raise retry/wait limits in vmbus_post_msg()
DoS protection conditions were altered in WS2016 and now it's easy to get
-EAGAIN returned from vmbus_post_msg() (e.g. when we try changing MTU on a
netvsc device in a loop). All vmbus_post_msg() callers don't retry the
operation and we usually end up with a non-functional device or crash.

While host's DoS protection conditions are unknown to me my tests show that
it can take up to 10 seconds before the message is sent so doing udelay()
is not an option, we really need to sleep. Almost all vmbus_post_msg()
callers are ready to sleep but there is one special case:
vmbus_initiate_unload() which can be called from interrupt/NMI context and
we can't sleep there. I'm also not sure about the lonely
vmbus_send_tl_connect_request() which has no in-tree users but its external
users are most likely waiting for the host to reply so sleeping there is
also appropriate.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-10 21:46:40 +01:00
Thomas Gleixner a5a1d1c291 clocksource: Use a plain u64 instead of cycle_t
There is no point in having an extra type for extra confusion. u64 is
unambiguous.

Conversion was done with the following coccinelle script:

@rem@
@@
-typedef u64 cycle_t;

@fix@
typedef cycle_t;
@@
-cycle_t
+u64

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
2016-12-25 11:04:12 +01:00
Stephen Hemminger 95096f2fbd uio-hv-generic: new userspace i/o driver for VMBus
This is a new driver to enable userspace networking on VMBus.
It is based largely on the similar driver that already exists
for PCI, and earlier work done by Brocade to support DPDK.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-06 11:52:49 +01:00
Stephen Hemminger fc76936d3e vmbus: add support for dynamic device id's
This patch adds sysfs interface to dynamically bind new UUID values
to existing VMBus device. This is useful for generic UIO driver to
act similar to uio_pci_generic.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-06 11:52:49 +01:00
Vitaly Kuznetsov 6ffc4b8535 hv: change clockevents unbind tactics
To get prepared to CPU offlining support we need co change the way how we
unbind clockevent devices. As one CPU may go online/offline multiple times
we need to bind it in hv_synic_init() and unbind it in hv_synic_cleanup().
There is an additional corner case: when we unload the module completely we
need to switch to some other clockevent mechanism before stopping VMBus or
we will hang. We can't call hv_synic_cleanup() before unloading VMBus as
we won't be able to send UNLOAD request and get a response so
hv_synic_clockevents_cleanup() has to live. Luckily, we can always call
clockevents_unbind_device(), even if it wasn't bound before and there is
no issue if we call it twice.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-06 11:10:54 +01:00
Vitaly Kuznetsov abd1026da4 hv: acquire vmbus_connection.channel_mutex in vmbus_free_channels()
"kernel BUG at drivers/hv/channel_mgmt.c:350!" is observed when hv_vmbus
module is unloaded. BUG_ON() was introduced in commit 85d9aa7051
("Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()") as
vmbus_free_channels() codepath was apparently forgotten.

Fixes: 85d9aa7051 ("Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()")

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-06 11:10:54 +01:00
Haiyang Zhang f45be72c8e hyperv: Fix spelling of HV_UNKOWN
Changed it to HV_UNKNOWN

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-06 11:10:54 +01:00
Greg Kroah-Hartman b7d91c9152 Merge 4.9-rc5 into char-misc-next
We want those fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-14 16:39:47 +01:00
K. Y. Srinivasan 3372592a14 Drivers: hv: vmbus: On the read path cleanup the logic to interrupt the host
Signal the host when we determine the host is to be signaled -
on th read path. The currrent code determines the need to signal in the
ringbuffer code and actually issues the signal elsewhere. This can result
in the host viewing this interrupt as spurious since the host may also
poll the channel. Make the necessary adjustments.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-07 10:01:18 +01:00
K. Y. Srinivasan 1f6ee4e7d8 Drivers: hv: vmbus: On write cleanup the logic to interrupt the host
Signal the host when we determine the host is to be signaled.
The currrent code determines the need to signal in the ringbuffer
code and actually issues the signal elsewhere. This can result
in the host viewing this interrupt as spurious since the host may also
poll the channel. Make the necessary adjustments.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-07 10:01:17 +01:00
K. Y. Srinivasan 74198eb4a4 Drivers: hv: vmbus: Base host signaling strictly on the ring state
One of the factors that can result in the host concluding that a given
guest in mounting a DOS attack is if the guest generates interrupts
to the host when the host is not expecting it. If these "spurious"
interrupts reach a certain rate, the host can throttle the guest to
minimize the impact. The host computation of the "expected number
of interrupts" is strictly based on the ring transitions. Until
the host logic is fixed, base the guest logic to interrupt solely
on the ring state.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-07 10:01:17 +01:00
Alex Ng 8500096017 Drivers: hv: balloon: Fix info request to show max page count
Balloon driver was only printing the size of the info blob and not the
actual content. This fixes it so that the info blob (max page count as
configured in Hyper-V) is printed out.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-07 10:01:17 +01:00
Alex Ng b357fd3908 Drivers: hv: vss: Operation timeouts should match host expectation
Increase the timeout of backup operations. When system is under I/O load,
it needs more time to freeze. These timeout values should also match the
host timeout values more closely.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-07 10:01:17 +01:00
Alex Ng 23d2cc0c29 Drivers: hv: vss: Improve log messages.
Adding log messages to help troubleshoot error cases and transaction
handling.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-07 10:01:17 +01:00
Alex Ng b3bb97b8a4 Drivers: hv: balloon: Add logging for dynamic memory operations
Added logging to help troubleshoot common ballooning, hot add,
and versioning issues.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-07 10:01:17 +01:00
Alex Ng 8ba8c0a111 Drivers: hv: balloon: Disable hot add when CONFIG_MEMORY_HOTPLUG is not set
If the guest does not support memory hotplugging, it should respond to
the host with zero pages added and successful result code. This signals
to the host that hotplugging is not supported and the host will avoid
sending future hot-add requests.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-07 10:01:17 +01:00
Alex Ng 3da0401b4d Drivers: hv: utils: Fix the mapping between host version and protocol to use
We should intentionally declare the protocols to use for every known host
and default to using the latest protocol if the host is unknown or new.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-07 10:01:17 +01:00
Vitaly Kuznetsov d7edd31ba9 Drivers: hv: utils: reduce HV_UTIL_NEGO_TIMEOUT timeout
I discovered that at least WS2016TP5 host has 60 seconds timeout for the
ICMSGTYPE_NEGOTIATE message so we need to lower guest's timeout a little
bit to make sure we always respond in time. Let's make it 55 seconds.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-07 10:01:16 +01:00
Stephen Hemminger f6b2db084b vmbus: make sysfs names consistent with PCI
In commit 9a56e5d6a0ba ("Drivers: hv: make VMBus bus ids persistent")
the name of vmbus devices in sysfs changed to be (in 4.9-rc1):
  /sys/bus/vmbus/vmbus-6aebe374-9ba0-11e6-933c-00259086b36b

The prefix ("vmbus-") is redundant and differs from how PCI is
represented in sysfs. Therefore simplify to:
  /sys/bus/vmbus/6aebe374-9ba0-11e6-933c-00259086b36b

Please merge this before 4.9 is released and the old format
has to live forever.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-01 09:07:13 -06:00
Long Li 407a3aee6e hv: do not lose pending heartbeat vmbus packets
The host keeps sending heartbeat packets independent of the
guest responding to them.  Even though we respond to the heartbeat messages at
interrupt level, we can have situations where there maybe multiple heartbeat
messages pending that have not been responded to. For instance this occurs when the
VM is paused and the host continues to send the heartbeat messages.
Address this issue by draining and responding to all
the heartbeat messages that maybe pending.

Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-25 08:52:10 +02:00
Vitaly Kuznetsov e7fca5d860 Drivers: hv: get rid of id in struct vmbus_channel
The auto incremented counter is not being used anymore, get rid of it.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27 12:35:49 +02:00
Vitaly Kuznetsov b294809dbf Drivers: hv: make VMBus bus ids persistent
Some tools use bus ids to identify devices and they count on the fact
that these ids are persistent across reboot. This may be not true for
VMBus as we use auto incremented counter from alloc_channel() as such
id. Switch to using if_instance from channel offer, this id is supposed
to be persistent.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27 12:35:49 +02:00
Vivek yadav 3ba1eb17b6 Drivers: hv: hv_util: Avoid dynamic allocation in time synch
Under stress, we have seen allocation failure in time synch code. Avoid
this dynamic allocation.

Signed-off-by: Vivek Yadav <vyadav@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-09 13:48:23 +02:00
Alex Ng 8e1d260738 Drivers: hv: utils: Support TimeSync version 4.0 protocol samples.
This enables support for more accurate TimeSync v4 samples when hosted
under Windows Server 2016 and newer hosts.

The new time samples include a "vmreferencetime" field that represents
the guest's TSC value when the host generated its time sample. This value
lets the guest calculate the latency in receiving the time sample. The
latency is added to the sample host time prior to updating the clock.

Signed-off-by: Alex Ng <alexng@messages.microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-08 13:53:07 +02:00
Alex Ng 2e338f7e03 Drivers: hv: utils: Use TimeSync samples to adjust the clock after boot.
Only the first 50 samples after boot were being used to discipline the
clock. After the first 50 samples, any samples from the host were ignored
and the guest clock would eventually drift from the host clock.

This patch allows TimeSync-enabled guests to continuously synchronize the
clock with the host clock, even after the first 50 samples.

Signed-off-by: Alex Ng <alexng@messages.microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-08 13:53:07 +02:00
Alex Ng abeda47ebb Drivers: hv: utils: Rename version definitions to reflect protocol version.
Different Windows host versions may reuse the same protocol version when
negotiating the TimeSync, Shutdown, and Heartbeat protocols. We should only
refer to the protocol version to avoid conflating the two concepts.

Signed-off-by: Alex Ng <alexng@messages.microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-08 13:53:07 +02:00
Dexuan Cui 0f98829a99 Drivers: hv: vmbus: suppress some "hv_vmbus: Unknown GUID" warnings
Some VMBus devices are not needed by Linux guest[1][2], and, VMBus channels
of Hyper-V Sockets don't really mean usual synthetic devices, so let's
suppress the warnings for them.

[1] https://support.microsoft.com/en-us/kb/2925727
[2] https://msdn.microsoft.com/en-us/library/jj980180(v=winembedded.81).aspx

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-07 12:57:55 +02:00
Stephen Hemminger e2e8084134 Driver: hv: vmbus: Make mmio resource local
This fixes a sparse warning because hyperv_mmio resources
are only used in this one file and should be static.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-07 12:57:55 +02:00
Alex Ng db886e4d24 Drivers: hv: utils: Check VSS daemon is listening before a hot backup
Hyper-V host will send a VSS_OP_HOT_BACKUP request to check if guest is
ready for a live backup/snapshot. The driver should respond to the check
only if the daemon is running and listening to requests. This allows the
host to fallback to standard snapshots in case the VSS daemon is not
running.

Signed-off-by: Alex Ng <alexng@messages.microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-02 17:22:51 +02:00
Alex Ng 497af84b81 Drivers: hv: utils: Continue to poll VSS channel after handling requests.
Multiple VSS_OP_HOT_BACKUP requests may arrive in quick succession, even
though the host only signals once. The driver wass handling the first
request while ignoring the others in the ring buffer. We should poll the
VSS channel after handling a request to continue processing other requests.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-02 17:22:51 +02:00
K. Y. Srinivasan 509879bdb3 Drivers: hv: Introduce a policy for controlling channel affinity
Introduce a mechanism to control how channels will be affinitized. We will
support two policies:

1. HV_BALANCED: All performance critical channels will be dstributed
evenly amongst all the available NUMA nodes. Once the Node is assigned,
we will assign the CPU based on a simple round robin scheme.

2. HV_LOCALIZED: Only the primary channels are distributed across all
NUMA nodes. Sub-channels will be in the same NUMA node as the primary
channel. This is the current behaviour.

The default policy will be the HV_BALANCED as it can minimize the remote
memory access on NUMA machines with applications that span NUMA nodes.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-02 17:22:51 +02:00
Vitaly Kuznetsov f24f0b495b Drivers: hv: ring_buffer: use wrap around mappings in hv_copy{from, to}_ringbuffer()
With wrap around mappings for ring buffers we can always use a single
memcpy() to do the job.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-02 17:22:51 +02:00
Vitaly Kuznetsov 9988ce6856 Drivers: hv: ring_buffer: wrap around mappings for ring buffers
Make it possible to always use a single memcpy() or to provide a direct
link to a packet on the ring buffer by creating virtual mapping for two
copies of the ring buffer with vmap(). Utilize currently empty
hv_ringbuffer_cleanup() to do the unmap.

While on it, replace sizeof(struct hv_ring_buffer) check
in hv_ringbuffer_init() with BUILD_BUG_ON() as it is a compile time check.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-02 17:22:51 +02:00
Vitaly Kuznetsov 98f531b10d Drivers: hv: cleanup vmbus_open() for wrap around mappings
In preparation for doing wrap around mappings for ring buffers cleanup
vmbus_open() function:
- check that ring sizes are PAGE_SIZE aligned (they are for all in-kernel
  drivers now);
- kfree(open_info) on error only after we kzalloc() it (not an issue as it
  is valid to call kfree(NULL);
- rename poorly named labels;
- use alloc_pages() instead of __get_free_pages() as we need struct page
  pointer for future.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-02 17:22:51 +02:00
Alex Ng b605c2d913 Drivers: hv: balloon: Use available memory value in pressure report
Reports for available memory should use the si_mem_available() value.
The previous freeram value does not include available page cache memory.

Signed-off-by: Alex Ng <alexng@messages.microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:42 +02:00
Vitaly Kuznetsov eece30b9f0 Drivers: hv: balloon: replace ha_region_mutex with spinlock
lockdep reports possible circular locking dependency when udev is used
for memory onlining:

 systemd-udevd/3996 is trying to acquire lock:
  ((memory_chain).rwsem){++++.+}, at: [<ffffffff810d137e>] __blocking_notifier_call_chain+0x4e/0xc0

 but task is already holding lock:
  (&dm_device.ha_region_mutex){+.+.+.}, at: [<ffffffffa015382e>] hv_memory_notifier+0x5e/0xc0 [hv_balloon]
 ...

which is probably a false positive because we take and release
ha_region_mutex from memory notifier chain depending on the arg. No real
deadlocks were reported so far (though I'm not really sure about
preemptible kernels...) but we don't really need to hold the mutex
for so long. We use it to protect ha_region_list (and its members) and the
num_pages_onlined counter. None of these operations require us to sleep
and nothing is slow, switch to using spinlock with interrupts disabled.

While on it, replace list_for_each -> list_for_each_entry as we actually
need entries in all these cases, drop meaningless list_empty() checks.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov a132c54cbc Drivers: hv: balloon: don't wait for ol_waitevent when memhp_auto_online is enabled
With the recently introduced in-kernel memory onlining
(MEMORY_HOTPLUG_DEFAULT_ONLINE) these is no point in waiting for pages
to come online in the driver and we can get rid of the waiting.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov cb7a5724c7 Drivers: hv: balloon: account for gaps in hot add regions
I'm observing the following hot add requests from the WS2012 host:

hot_add_req: start_pfn = 0x108200 count = 330752
hot_add_req: start_pfn = 0x158e00 count = 193536
hot_add_req: start_pfn = 0x188400 count = 239616

As the host doesn't specify hot add regions we're trying to create
128Mb-aligned region covering the first request, we create the 0x108000 -
0x160000 region and we add 0x108000 - 0x158e00 memory. The second request
passes the pfn_covered() check, we enlarge the region to 0x108000 -
0x190000 and add 0x158e00 - 0x188200 memory. The problem emerges with the
third request as it starts at 0x188400 so there is a 0x200 gap which is
not covered. As the end of our region is 0x190000 now it again passes the
pfn_covered() check were we just adjust the covered_end_pfn and make it
0x188400 instead of 0x188200 which means that we'll try to online
0x188200-0x188400 pages but these pages were never assigned to us and we
crash.

We can't react to such requests by creating new hot add regions as it may
happen that the whole suggested range falls into the previously identified
128Mb-aligned area so we'll end up adding nothing or create intersecting
regions and our current logic doesn't allow that. Instead, create a list of
such 'gaps' and check for them in the page online callback.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov 7cf3b79ec8 Drivers: hv: balloon: keep track of where ha_region starts
Windows 2012 (non-R2) does not specify hot add region in hot add requests
and the logic in hot_add_req() is trying to find a 128Mb-aligned region
covering the request. It may also happen that host's requests are not 128Mb
aligned and the created ha_region will start before the first specified
PFN. We can't online these non-present pages but we don't remember the real
start of the region.

This is a regression introduced by the commit 5abbbb75d7 ("Drivers: hv:
hv_balloon: don't lose memory when onlining order is not natural"). While
the idea of keeping the 'moving window' was wrong (as there is no guarantee
that hot add requests come ordered) we should still keep track of
covered_start_pfn. This is not a revert, the logic is different.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
K. Y. Srinivasan 3724287c0e Drivers: hv: vmbus: Implement a mechanism to tag the channel for low latency
On Hyper-V, performance critical channels use the monitor
mechanism to signal the host when the guest posts mesages
for the host. This mechanism minimizes the hypervisor intercepts
and also makes the host more efficient in that each time the
host is woken up, it processes a batch of messages as opposed to
just one. The goal here is improve the throughput and this is at
the expense of increased latency.
Implement a mechanism to let the client driver decide if latency
is important.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
K. Y. Srinivasan 8de0d7e951 Drivers: hv: vmbus: Reduce the delay between retries in vmbus_post_msg()
The current delay between retries is unnecessarily high and is negatively
affecting the time it takes to boot the system.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
K. Y. Srinivasan ccef9bcc02 Drivers: hv: vmbus: Enable explicit signaling policy for NIC channels
For synthetic NIC channels, enable explicit signaling policy as netvsc wants to
explicitly control when the host is to be signaled.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Dexuan Cui 638fea33ae Drivers: hv: vmbus: fix the race when querying & updating the percpu list
There is a rare race when we remove an entry from the global list
hv_context.percpu_list[cpu] in hv_process_channel_removal() ->
percpu_channel_deq() -> list_del(): at this time, if vmbus_on_event() ->
process_chn_event() -> pcpu_relid2channel() is trying to query the list,
we can get the kernel fault.

Similarly, we also have the issue in the code path: vmbus_process_offer() ->
percpu_channel_enq().

We can resolve the issue by disabling the tasklet when updating the list.

The patch also moves vmbus_release_relid() to a later place where
the channel has been removed from the per-cpu and the global lists.

Reported-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov e0fa3e5e7d Drivers: hv: utils: fix a race on userspace daemons registration
Background: userspace daemons registration protocol for Hyper-V utilities
drivers has two steps:
1) daemon writes its own version to kernel
2) kernel reads it and replies with module version
at this point we consider the handshake procedure being completed and we
do hv_poll_channel() transitioning the utility device to HVUTIL_READY
state. At this point we're ready to handle messages from kernel.

When hvutil_transport is in HVUTIL_TRANSPORT_CHARDEV mode we have a
single buffer for outgoing message. hvutil_transport_send() puts to this
buffer and till the buffer is cleared with hvt_op_read() returns -EFAULT
to all consequent calls. Host<->guest protocol guarantees there is no more
than one request at a time and we will not get new requests till we reply
to the previous one so this single message buffer is enough.

Now to the race. When we finish negotiation procedure and send kernel
module version to userspace with hvutil_transport_send() it goes into the
above mentioned buffer and if the daemon is slow enough to read it from
there we can get a collision when a request from the host comes, we won't
be able to put anything to the buffer so the request will be lost. To
solve the issue we need to know when the negotiation is really done (when
the version message is read by the daemon) and transition to HVUTIL_READY
state after this happens. Implement a callback on read to support this.
Old style netlink communication is not affected by the change, we don't
really know when these messages are delivered but we don't have a single
message buffer there.

Reported-by: Barry Davis <barry_davis@stormagic.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov 396e287fa2 Drivers: hv: get rid of timeout in vmbus_open()
vmbus_teardown_gpadl() can result in infinite wait when it is called on 5
second timeout in vmbus_open(). The issue is caused by the fact that gpadl
teardown operation won't ever succeed for an opened channel and the timeout
isn't always enough. As a guest, we can always trust the host to respond to
our request (and there is nothing we can do if it doesn't).

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov 7cc80c9807 Drivers: hv: don't leak memory in vmbus_establish_gpadl()
In some cases create_gpadl_header() allocates submessages but we never
free them.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:41 +02:00
Vitaly Kuznetsov 4d63763296 Drivers: hv: get rid of redundant messagecount in create_gpadl_header()
We use messagecount only once in vmbus_establish_gpadl() to check if
it is safe to iterate through the submsglist. We can just initialize
the list header in all cases in create_gpadl_header() instead.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:40 +02:00
Vitaly Kuznetsov a9f61ca793 Drivers: hv: avoid vfree() on crash
When we crash from NMI context (e.g. after NMI injection from host when
'sysctl -w kernel.unknown_nmi_panic=1' is set) we hit

    kernel BUG at mm/vmalloc.c:1530!

as vfree() is denied. While the issue could be solved with in_nmi() check
instead I opted for skipping vfree on all sorts of crashes to reduce the
amount of work which can cause consequent crashes. We don't really need to
free anything on crash.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 13:05:40 +02:00
Stephan Mueller 4b44f2d18a random: add interrupt callback to VMBus IRQ handler
The Hyper-V Linux Integration Services use the VMBus implementation for
communication with the Hypervisor. VMBus registers its own interrupt
handler that completely bypasses the common Linux interrupt handling.
This implies that the interrupt entropy collector is not triggered.

This patch adds the interrupt entropy collection callback into the VMBus
interrupt handler function.

Cc: stable@kernel.org
Signed-off-by: Stephan Mueller <stephan.mueller@atsec.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-06-13 11:54:33 -04:00
Vitaly Kuznetsov d19a55d6ed Drivers: hv: balloon: reset host_specified_ha_region
We set host_specified_ha_region = true on certain request but this is a
global state which stays 'true' forever. We need to reset it when we
receive a request where ha_region is not specified. I did not see any
real issues, the bug was found by code inspection.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 09:23:14 -07:00
Vitaly Kuznetsov 77c0c9735b Drivers: hv: balloon: don't crash when memory is added in non-sorted order
When we iterate through all HA regions in handle_pg_range() we have an
assumption that all these regions are sorted in the list and the
'start_pfn >= has->end_pfn' check is enough to find the proper region.
Unfortunately it's not the case with WS2016 where host can hot-add regions
in a different order. We end up modifying the wrong HA region and crashing
later on pages online. Modify the check to make sure we found the region
we were searching for while iterating. Fix the same check in pfn_covered()
as well.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 09:23:14 -07:00
Vitaly Kuznetsov cd95aad557 Drivers: hv: vmbus: handle various crash scenarios
Kdump keeps biting. Turns out CHANNELMSG_UNLOAD_RESPONSE is always
delivered to the CPU which was used for initial contact or to CPU0
depending on host version. vmbus_wait_for_unload() doesn't account for
the fact that in case we're crashing on some other CPU we won't get the
CHANNELMSG_UNLOAD_RESPONSE message and our wait on the current CPU will
never end.

Do the following:
1) Check for completion_done() in the loop. In case interrupt handler is
   still alive we'll get the confirmation we need.

2) Read message pages for all CPUs message page as we're unsure where
   CHANNELMSG_UNLOAD_RESPONSE is going to be delivered to. We can race with
   still-alive interrupt handler doing the same, add cmpxchg() to
   vmbus_signal_eom() to not lose CHANNELMSG_UNLOAD_RESPONSE message.

3) Cleanup message pages on all CPUs. This is required (at least for the
   current CPU as we're clearing CPU0 messages now but we may want to bring
   up additional CPUs on crash) as new messages won't be delivered till we
   consume what's pending. On boot we'll place message pages somewhere else
   and we won't be able to read stale messages.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 09:23:14 -07:00
Vitaly Kuznetsov 4dbfc2e680 Drivers: hv: kvp: fix IP Failover
Hyper-V VMs can be replicated to another hosts and there is a feature to
set different IP for replicas, it is called 'Failover TCP/IP'. When
such guest starts Hyper-V host sends it KVP_OP_SET_IP_INFO message as soon
as we finish negotiation procedure. The problem is that it can happen (and
it actually happens) before userspace daemon connects and we reply with
HV_E_FAIL to the message. As there are no repetitions we fail to set the
requested IP.

Solve the issue by postponing our reply to the negotiation message till
userspace daemon is connected. We can't wait too long as there is a
host-side timeout (cca. 75 seconds) and if we fail to reply in this time
frame the whole KVP service will become inactive. The solution is not
ideal - if it takes userspace daemon more than 60 seconds to connect
IP Failover will still fail but I don't see a solution with our current
separation between kernel and userspace parts.

Other two modules (VSS and FCOPY) don't require such delay, leave them
untouched.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 09:23:14 -07:00
Jake Oshins ea37a6b8a0 drivers:hv: Separate out frame buffer logic when picking MMIO range
Simplify the logic that picks MMIO ranges by pulling out the
logic related to trying to lay frame buffer claim on top of where
the firmware placed the frame buffer.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:01:37 -07:00
Jake Oshins 6d146aefba drivers:hv: Record MMIO range in use by frame buffer
Later in the boot sequence, we need to figure out which memory
ranges can be given out to various paravirtual drivers.  The
hyperv_fb driver should, ideally, be placed right on top of
the frame buffer, without some other device getting plopped on
top of this range in the meantime.  Recording this now allows
that to be guaranteed.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:01:37 -07:00
Jake Oshins be000f93e5 drivers:hv: Track allocations of children of hv_vmbus in private resource tree
This patch changes vmbus_allocate_mmio() and vmbus_free_mmio() so
that when child paravirtual devices allocate memory-mapped I/O
space, they allocate it privately from a resource tree pointed
at by hyperv_mmio and also by the public resource tree
iomem_resource.  This allows the region to be marked as "busy"
in the private tree, but a "bridge window" in the public tree,
guaranteeing that no two bridge windows will overlap each other
but while also allowing the PCI device children of the bridge
windows to overlap that window.

One might conclude that this belongs in the pnp layer, rather
than in this driver.  Rafael Wysocki, the maintainter of the
pnp layer, has previously asked that we not modify the pnp layer
as it is considered deprecated.  This patch is thus essentially
a workaround.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:01:37 -07:00
Jake Oshins 23a0683186 drivers:hv: Reverse order of resources in hyperv_mmio
A patch later in this series allocates child nodes
in this resource tree.  For that to work, this tree
needs to be sorted in ascending order.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:01:37 -07:00
Jake Oshins 97fb77dc87 drivers:hv: Make a function to free mmio regions through vmbus
This patch introduces a function that reverses everything
done by vmbus_allocate_mmio().  Existing code just called
release_mem_region().  Future patches in this series
require a more complex sequence of actions, so this function
is introduced to wrap those actions.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:01:37 -07:00
Jake Oshins e16dad6bfe drivers:hv: Lock access to hyperv_mmio resource tree
In existing code, this tree of resources is created
in single-threaded code and never modified after it is
created, and thus needs no locking.  This patch introduces
a semaphore for tree access, as other patches in this
series introduce run-time modifications of this resource
tree which can happen on multiple threads.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:01:37 -07:00
K. Y. Srinivasan ab028db41c Drivers: hv: vmbus: Implement APIs to support "in place" consumption of vmbus packets
Implement APIs for in-place consumption of vmbus packets. Currently, each
packet is copied and processed one at a time and as part of processing
each packet we potentially may signal the host (if it is waiting for
room to produce a packet).

These APIs help batched in-place processing of vmbus packets.
We also optimize host signaling by having a separate API to signal
the end of in-place consumption. With netvsc using these APIs,
on an iperf run on average I see about 20X reduction in checks to
signal the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:19 -07:00
K. Y. Srinivasan 687f32e6d9 Drivers: hv: vmbus: Move some ring buffer functions to hyperv.h
In preparation for implementing APIs for in-place consumption of VMBUS
packets, movve some ring buffer functionality into hyperv.h

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:19 -07:00
K. Y. Srinivasan 5cc472477f Drivers: hv: vmbus: Export the vmbus_set_event() API
In preparation for moving some ring buffer functionality out of the
vmbus driver, export the API for signaling the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:19 -07:00
K. Y. Srinivasan dcd0eeca44 Drivers: hv: vmbus: Use the new virt_xx barrier code
Use the virt_xx barriers that have been defined for use in virtual machines.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:19 -07:00
K. Y. Srinivasan d45faaeedb Drivers: hv: vmbus: Use READ_ONCE() to read variables that are volatile
Use the READ_ONCE macro to access variabes that can change asynchronously.
This is the recommended mechanism for dealing with "unsafe" compiler
optimizations.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:19 -07:00
K. Y. Srinivasan a6341f0000 Drivers: hv: vmbus: Introduce functions for estimating room in the ring buffer
Introduce separate functions for estimating how much can be read from
and written to the ring buffer.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:19 -07:00
K. Y. Srinivasan a389fcfd2c Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()
On the consumer side, we have interrupt driven flow management of the
producer. It is sufficient to base the signaling decision on the
amount of space that is available to write after the read is complete.
The current code samples the previous available space and uses this
in making the signaling decision. This state can be stale and is
unnecessary. Since the state can be stale, we end up not signaling
the host (when we should) and this can result in a hang. Fix this
problem by removing the unnecessary check. I would like to thank
Arseney Romanenko <arseneyr@microsoft.com> for pointing out this issue.

Also, issue a full memory barrier before making the signaling descision
to correctly deal with potential reordering of the write (read index)
followed by the read of pending_sz.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Dexuan Cui <decui@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:16 -07:00
Linus Torvalds 8eee93e257 Char/Misc patches for 4.6-rc1
Here is the big char/misc driver update for 4.6-rc1.
 
 The majority of the patches here is hwtracing and some new mic drivers,
 but there's a lot of other driver updates as well.  Full details in the
 shortlog.
 
 All have been in linux-next for a while with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc updates from Greg KH:
 "Here is the big char/misc driver update for 4.6-rc1.

  The majority of the patches here is hwtracing and some new mic
  drivers, but there's a lot of other driver updates as well.  Full
  details in the shortlog.

  All have been in linux-next for a while with no reported issues"

* tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (238 commits)
  goldfish: Fix build error of missing ioremap on UM
  nvmem: mediatek: Fix later provider initialization
  nvmem: imx-ocotp: Fix return value of imx_ocotp_read
  nvmem: Fix dependencies for !HAS_IOMEM archs
  char: genrtc: replace blacklist with whitelist
  drivers/hwtracing: make coresight-etm-perf.c explicitly non-modular
  drivers: char: mem: fix IS_ERROR_VALUE usage
  char: xillybus: Fix internal data structure initialization
  pch_phub: return -ENODATA if ROM can't be mapped
  Drivers: hv: vmbus: Support kexec on ws2012 r2 and above
  Drivers: hv: vmbus: Support handling messages on multiple CPUs
  Drivers: hv: utils: Remove util transport handler from list if registration fails
  Drivers: hv: util: Pass the channel information during the init call
  Drivers: hv: vmbus: avoid unneeded compiler optimizations in vmbus_wait_for_unload()
  Drivers: hv: vmbus: remove code duplication in message handling
  Drivers: hv: vmbus: avoid wait_for_completion() on crash
  Drivers: hv: vmbus: don't loose HVMSG_TIMER_EXPIRED messages
  misc: at24: replace memory_accessor with nvmem_device_read
  eeprom: 93xx46: extend driver to plug into the NVMEM framework
  eeprom: at25: extend driver to plug into the NVMEM framework
  ...
2016-03-17 13:47:50 -07:00
Alex Ng 7268644734 Drivers: hv: vmbus: Support kexec on ws2012 r2 and above
WS2012 R2 and above hosts can support kexec in that thay can support
reconnecting to the host (as would be needed in the kexec path)
on any CPU. Enable this. Pre ws2012 r2 hosts don't have this ability
and consequently cannot support kexec.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
K. Y. Srinivasan d81274aae6 Drivers: hv: vmbus: Support handling messages on multiple CPUs
Starting with Windows 2012 R2, message inteerupts can be delivered
on any VCPU in the guest. Support this functionality.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
Alex Ng e66853b090 Drivers: hv: utils: Remove util transport handler from list if registration fails
If util transport fails to initialize for any reason, the list of transport
handlers may become corrupted due to freeing the transport handler without
removing it from the list. Fix this by cleaning it up from the list.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
K. Y. Srinivasan b9830d120c Drivers: hv: util: Pass the channel information during the init call
Pass the channel information to the util drivers that need to defer
reading the channel while they are processing a request. This would address
the following issue reported by Vitaly:

Commit 3cace4a616 ("Drivers: hv: utils: run polling callback always in
interrupt context") removed direct *_transaction.state = HVUTIL_READY
assignments from *_handle_handshake() functions introducing the following
race: if a userspace daemon connects before we get first non-negotiation
request from the server hv_poll_channel() won't set transaction state to
HVUTIL_READY as (!channel) condition will fail, we set it to non-NULL on
the first real request from the server.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
Vitaly Kuznetsov d452ab7b4c Drivers: hv: vmbus: avoid unneeded compiler optimizations in vmbus_wait_for_unload()
Message header is modified by the hypervisor and we read it in a loop,
we need to prevent compilers from optimizing accesses. There are no such
optimizations at this moment, this is just a future proof.

Suggested-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Radim Kr.má<rkrcmar@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
Vitaly Kuznetsov 0f70b66975 Drivers: hv: vmbus: remove code duplication in message handling
We have 3 functions dealing with messages and they all implement
the same logic to finalize reads, move it to vmbus_signal_eom().

Suggested-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Radim Kr.má<rkrcmar@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
Vitaly Kuznetsov 75ff3a8a91 Drivers: hv: vmbus: avoid wait_for_completion() on crash
wait_for_completion() may sleep, it enables interrupts and this
is something we really want to avoid on crashes because interrupt
handlers can cause other crashes. Switch to the recently introduced
vmbus_wait_for_unload() doing busy wait instead.

Reported-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Radim Kr.má<rkrcmar@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
Vitaly Kuznetsov 7be3e16944 Drivers: hv: vmbus: don't loose HVMSG_TIMER_EXPIRED messages
We must handle HVMSG_TIMER_EXPIRED messages in the interrupt context
and we offload all the rest to vmbus_on_msg_dpc() tasklet. This functions
loops to see if there are new messages pending. In case we'll ever see
HVMSG_TIMER_EXPIRED message there we're going to lose it as we can't
handle it from there. Avoid looping in vmbus_on_msg_dpc(), we're OK
with handling one message per interrupt.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Radim Kr.má<rkrcmar@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
Andrey Smetanin 18f098618a drivers/hv: Move VMBus hypercall codes into Hyper-V UAPI header
VMBus hypercall codes inside Hyper-V UAPI header will
be used by QEMU to implement VMBus host devices support.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Joerg Roedel <joro@8bytes.org>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
[Do not rename the constant at the same time as moving it, as that
 would cause semantic conflicts with the Hyper-V tree. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 18:48:40 +01:00
K. Y. Srinivasan fe760e4d64 Drivers: hv: vmbus: Give control over how the ring access is serialized
On the channel send side, many of the VMBUS
device drivers explicity serialize access to the
outgoing ring buffer. Give more control to the
VMBUS device drivers in terms how to serialize
accesss to the outgoing ring buffer.
The default behavior will be to aquire the
ring lock to preserve the current behavior.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
K. Y. Srinivasan 3eba9a77d5 Drivers: hv: vmbus: Eliminate the spin lock on the read path
The function hv_ringbuffer_read() is called always on a pre-assigned
CPU. Each chnnel is bound to a specific CPU and this function is
always called on the CPU the channel is bound. There is no need to
acquire the spin lock; get rid of this overhead.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Dexuan Cui 85d9aa7051 Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()
The hvsock driver needs this API to release all the resources related
to the channel.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Dexuan Cui 499e8401a5 Drivers: hv: vmbus: add a per-channel rescind callback
This will be used by the coming hv_sock driver.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Dexuan Cui 8981da320a Drivers: hv: vmbus: add a hvsock flag in struct hv_driver
Only the coming hv_sock driver has a "true" value for this flag.

We treat the hvsock offers/channels as special VMBus devices.
Since the hv_sock driver handles all the hvsock offers/channels, we need to
tweak vmbus_match() for hv_sock driver, so we introduce this flag.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Dexuan Cui 5c23a1a5c6 Drivers: hv: vmbus: define a new VMBus message type for hvsock
A function to send the type of message is also added.

The coming net/hvsock driver will use this function to proactively request
the host to offer a VMBus channel for a new hvsock connection.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Dexuan Cui 5f363bc38f Drivers: hv: vmbus: vmbus_sendpacket_ctl: hvsock: avoid unnecessary signaling
When the hvsock channel's outbound ringbuffer is full (i.e.,
hv_ringbuffer_write() returns -EAGAIN), we should avoid the unnecessary
signaling the host.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Vitaly Kuznetsov 3ccb4fd8f4 Drivers: hv: vmbus: don't manipulate with clocksources on crash
clocksource_change_rating() involves mutex usage and can't be called
in interrupt context. It also makes sense to avoid doing redundant work
on crash.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Vitaly Kuznetsov 415719160d Drivers: hv: vmbus: avoid scheduling in interrupt context in vmbus_initiate_unload()
We have to call vmbus_initiate_unload() on crash to make kdump work but
the crash can also be happening in interrupt (e.g. Sysrq + c results in
such) where we can't schedule or the following will happen:

[  314.905786] bad: scheduling from the idle thread!

Just skipping the wait (and even adding some random wait here) won't help:
to make host-side magic working we're supposed to receive CHANNELMSG_UNLOAD
(and actually confirm the fact that we received it) but we can't use
interrupt-base path (vmbus_isr()-> vmbus_on_msg_dpc()). Implement a simple
busy wait ignoring all the other messages and use it if we're in an
interrupt context.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Vitaly Kuznetsov 79fd8e7066 Drivers: hv: vmbus: avoid infinite loop in init_vp_index()
When we pick a CPU to use for a new subchannel we try find a non-used one
on the appropriate NUMA node, we keep track of them with the
primary->alloced_cpus_in_node mask. Under normal circumstances we don't run
out of available CPUs but it is possible when we we don't initialize some
cpus in Linux, e.g. when we boot with 'nr_cpus=' limitation.

Avoid the infinite loop in init_vp_index() by checking that we still have
non-used CPUs in the alloced_cpus_in_node mask and resetting it in case
we don't.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
K. Y. Srinivasan 7047f17d70 Drivers: hv: vmbus: Add vendor and device atttributes
Add vendor and device attributes to VMBUS devices. These will be used
by Hyper-V tools as well user-level RDMA libraries that will use the
vendor/device tuple to discover the RDMA device.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:32:57 -08:00
K. Y. Srinivasan 1b807e1011 Drivers: hv: vmbus: Cleanup vmbus_set_event()
Cleanup vmbus_set_event() by inlining the hypercall to post
the event and since the return value of vmbus_set_event() is not checked,
make it void. As part of this cleanup, get rid of the function
hv_signal_event() as it is only callled from vmbus_set_event().

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:32:57 -08:00
Linus Torvalds 4c257ec37b char/misc patches for 4.5-rc1
Here's the big set of char/misc patches for 4.5-rc1.
 
 Nothing major, lots of different driver subsystem updates, full details
 in the shortlog.  All of these have been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc updates from Greg KH:
 "Here's the big set of char/misc patches for 4.5-rc1.

  Nothing major, lots of different driver subsystem updates, full
  details in the shortlog.  All of these have been in linux-next for a
  while"

* tag 'char-misc-4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (71 commits)
  mei: fix fasync return value on error
  parport: avoid assignment in if
  parport: remove unneeded space
  parport: change style of NULL comparison
  parport: remove unnecessary out of memory message
  parport: remove braces
  parport: quoted strings should not be split
  parport: code indent should use tabs
  parport: fix coding style
  parport: EXPORT_SYMBOL should follow function
  parport: remove trailing white space
  parport: fix a trivial typo
  coresight: Fix a typo in Kconfig
  coresight: checking for NULL string in coresight_name_match()
  Drivers: hv: vmbus: Treat Fibre Channel devices as performance critical
  Drivers: hv: utils: fix hvt_op_poll() return value on transport destroy
  Drivers: hv: vmbus: fix the building warning with hyperv-keyboard
  extcon: add Maxim MAX3355 driver
  Drivers: hv: ring_buffer: eliminate hv_ringbuffer_peek()
  Drivers: hv: remove code duplication between vmbus_recvpacket()/vmbus_recvpacket_raw()
  ...
2016-01-13 10:23:36 -08:00
K. Y. Srinivasan 879a650a27 Drivers: hv: vmbus: Treat Fibre Channel devices as performance critical
For performance critical devices, we distribute the incoming
channel interrupt load across available CPUs in the guest.
Include Fibre channel devices in the set of devices for which
we would distribute the interrupt load.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-21 13:14:56 -08:00
Vitaly Kuznetsov 77b744a598 Drivers: hv: utils: fix hvt_op_poll() return value on transport destroy
The return type of hvt_op_poll() is unsigned int and -EBADF is
inappropriate, poll functions return POLL* statuses.

Reported-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-21 13:14:56 -08:00
Andrey Smetanin c71acc4c74 drivers/hv: Move struct hv_timer_message_payload into UAPI Hyper-V x86 header
This struct is required for Hyper-V SynIC timers implementation inside KVM
and for upcoming Hyper-V VMBus support by userspace(QEMU). So place it into
Hyper-V UAPI header.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-16 18:49:41 +01:00
Andrey Smetanin 5b423efe11 drivers/hv: Move struct hv_message into UAPI Hyper-V x86 header
This struct is required for Hyper-V SynIC timers implementation inside KVM
and for upcoming Hyper-V VMBus support by userspace(QEMU). So place it into
Hyper-V UAPI header.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-16 18:49:40 +01:00
Andrey Smetanin 4f39bcfd1c drivers/hv: Move HV_SYNIC_STIMER_COUNT into Hyper-V UAPI x86 header
This constant is required for Hyper-V SynIC timers MSR's
support by userspace(QEMU).

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-16 18:49:40 +01:00
Andrey Smetanin 7797dcf63f drivers/hv: replace enum hv_message_type by u32
enum hv_message_type inside struct hv_message, hv_post_message
is not size portable. Replace enum by u32.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-16 18:49:39 +01:00
Vitaly Kuznetsov 940b68e2c3 Drivers: hv: ring_buffer: eliminate hv_ringbuffer_peek()
Currently, there is only one user for hv_ringbuffer_read()/
hv_ringbuffer_peak() functions and the usage of these functions is:
- insecure as we drop ring_lock between them, someone else (in theory
  only) can acquire it in between;
- non-optimal as we do a number of things (acquire/release the above
  mentioned lock, calculate available space on the ring, ...) twice and
  this path is performance-critical.

Remove hv_ringbuffer_peek() moving the logic from __vmbus_recvpacket() to
hv_ringbuffer_read().

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:27:30 -08:00
Vitaly Kuznetsov 667d374064 Drivers: hv: remove code duplication between vmbus_recvpacket()/vmbus_recvpacket_raw()
vmbus_recvpacket() and vmbus_recvpacket_raw() are almost identical but
there are two discrepancies:
1) vmbus_recvpacket() doesn't propagate errors from hv_ringbuffer_read()
   which looks like it is not desired.
2) There is an error message printed in packetlen > bufferlen case in
   vmbus_recvpacket(). I'm removing it as it is usless for users to see
   such messages and /vmbus_recvpacket_raw() doesn't have it.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:27:30 -08:00
Vitaly Kuznetsov b5f53dde8d Drivers: hv: ring_buffer: remove code duplication from hv_ringbuffer_peek/read()
hv_ringbuffer_peek() does the same as hv_ringbuffer_read() without
advancing the read index. The only functional change this patch brings
is moving hv_need_to_signal_on_read() call under the ring_lock but this
function is just a couple of comparisons.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:27:30 -08:00
Vitaly Kuznetsov 822f18d4d3 Drivers: hv: ring_buffer.c: fix comment style
Convert 6+-string comments repeating function names to normal kernel-style
comments and fix a couple of other comment style issues. No textual or
functional changes intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:27:30 -08:00
Vitaly Kuznetsov 9420098adc Drivers: hv: utils: fix crash when device is removed from host side
The crash is observed when a service is being disabled host side while
userspace daemon is connected to the device:

[   90.244859] general protection fault: 0000 [#1] SMP
...
[   90.800082] Call Trace:
[   90.800082]  [<ffffffff81187008>] __fput+0xc8/0x1f0
[   90.800082]  [<ffffffff8118716e>] ____fput+0xe/0x10
...
[   90.800082]  [<ffffffff81015278>] do_signal+0x28/0x580
[   90.800082]  [<ffffffff81086656>] ? finish_task_switch+0xa6/0x180
[   90.800082]  [<ffffffff81443ebf>] ? __schedule+0x28f/0x870
[   90.800082]  [<ffffffffa01ebbaa>] ? hvt_op_read+0x12a/0x140 [hv_utils]
...

The problem is that hvutil_transport_destroy() which does misc_deregister()
freeing the appropriate device is reachable by two paths: module unload
and from util_remove(). While module unload path is protected by .owner in
struct file_operations util_remove() path is not. Freeing the device while
someone holds an open fd for it is a show stopper.

In general, it is not possible to revoke an fd from all users so the only
way to solve the issue is to defer freeing the hvutil_transport structure.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:27:30 -08:00
Vitaly Kuznetsov a15025660d Drivers: hv: utils: introduce HVUTIL_TRANSPORT_DESTROY mode
When Hyper-V host asks us to remove some util driver by closing the
appropriate channel there is no easy way to force the current file
descriptor holder to hang up but we can start to respond -EBADF to all
operations asking it to exit gracefully.

As we're setting hvt->mode from two separate contexts now we need to use
a proper locking.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:27:30 -08:00
Vitaly Kuznetsov a72f3a4ccf Drivers: hv: utils: rename outmsg_lock
As a preparation to reusing outmsg_lock to protect test-and-set openrations
on 'mode' rename it the more general 'lock'.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:27:30 -08:00
Vitaly Kuznetsov 1f75338b6f Drivers: hv: utils: fix memory leak on on_msg() failure
inmsg should be freed in case of on_msg() failure to avoid memory leak.
Preserve the error code from on_msg().

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:27:30 -08:00
K. Y. Srinivasan 2d0c3b5ad7 Drivers: hv: utils: Invoke the poll function after handshake
When the handshake with daemon is complete, we should poll the channel since
during the handshake, we will not be processing any messages. This is a
potential bug if the host is waiting for a response from the guest.
I would like to thank Dexuan for pointing this out.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
K. Y. Srinivasan b282e4c06f Drivers: hv: vmbus: Force all channel messages to be delivered on CPU 0
Force all channel messages to be delivered on CPU0. These messages are not
performance critical and are used during the setup and teardown of the
channel.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
Andrey Smetanin c35b82ef02 drivers/hv: correct tsc page sequence invalid value
Hypervisor Top Level Functional Specification v3/4 says
that TSC page sequence value = -1(0xFFFFFFFF) is used to
indicate that TSC page no longer reliable source of reference
timer. Unfortunately, we found that Windows Hyper-V guest
side implementation uses sequence value = 0 to indicate
that Tsc page no longer valid. This is clearly visible
inside Windows 2012R2 ntoskrnl.exe HvlGetReferenceTime()
function dissassembly:

HvlGetReferenceTime proc near
                 xchg    ax, ax
loc_1401C3132:
                 mov     rax, cs:HvlpReferenceTscPage
                 mov     r9d, [rax]
                 test    r9d, r9d
                 jz      short loc_1401C3176
                 rdtsc
                 mov     rcx, cs:HvlpReferenceTscPage
                 shl     rdx, 20h
                 or      rdx, rax
                 mov     rax, [rcx+8]
                 mov     rcx, cs:HvlpReferenceTscPage
                 mov     r8, [rcx+10h]
                 mul     rdx
                 mov     rax, cs:HvlpReferenceTscPage
                 add     rdx, r8
                 mov     ecx, [rax]
                 cmp     ecx, r9d
                 jnz     short loc_1401C3132
                 jmp     short loc_1401C3184
loc_1401C3176:
                 mov     ecx, 40000020h
                 rdmsr
                 shl     rdx, 20h
                 or      rdx, rax
loc_1401C3184:
                 mov     rax, rdx
                 retn
HvlGetReferenceTime endp

This patch aligns Tsc page invalid sequence value with
Windows Hyper-V guest implementation which is more
compatible with both Hyper-V hypervisor and KVM hypervisor.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
K. Y. Srinivasan 8599846d73 Drivers: hv: vmbus: Fix a Host signaling bug
Currently we have two policies for deciding when to signal the host:
One based on the ring buffer state and the other based on what the
VMBUS client driver wants to do. Consider the case when the client
wants to explicitly control when to signal the host. In this case,
if the client were to defer signaling, we will not be able to signal
the host subsequently when the client does want to signal since the
ring buffer state will prevent the signaling. Implement logic to
have only one signaling policy in force for a given channel.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Tested-by: Haiyang Zhang <haiyangz@microsoft.com>
Cc: <stable@vger.kernel.org> # v4.2+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
Jake Oshins 40f26f3168 drivers:hv: Allow for MMIO claims that span ACPI _CRS records
This patch makes 16GB GPUs work in Hyper-V VMs, since, for
compatibility reasons, the Hyper-V BIOS lists MMIO ranges in 2GB
chunks in its root bus's _CRS object.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
Dexuan Cui d6f591e339 Drivers: hv: vmbus: channge vmbus_connection.channel_lock to mutex
spinlock is unnecessary here.
mutex is enough.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
Dexuan Cui f52078cf57 Drivers: hv: vmbus: release relid on error in vmbus_process_offer()
We want to simplify vmbus_onoffer_rescind() by not invoking
hv_process_channel_removal(NULL, ...).

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
Dexuan Cui 34c6801e33 Drivers: hv: vmbus: fix rescind-offer handling for device without a driver
In the path vmbus_onoffer_rescind() -> vmbus_device_unregister()  ->
device_unregister() -> ... -> __device_release_driver(), we can see for a
device without a driver loaded: dev->driver is NULL, so
dev->bus->remove(dev), namely vmbus_remove(), isn't invoked.

As a result, vmbus_remove() -> hv_process_channel_removal() isn't invoked
and some cleanups(like sending a CHANNELMSG_RELID_RELEASED message to the
host) aren't done.

We can demo the issue this way:
1. rmmod hv_utils;
2. disable the Heartbeat Integration Service in Hyper-V Manager and lsvmbus
shows the device disappears.
3. re-enable the Heartbeat in Hyper-V Manager and modprobe hv_utils, but
lsvmbus shows the device can't appear again.
This is because, the host thinks the VM hasn't released the relid, so can't
re-offer the device to the VM.

We can fix the issue by moving hv_process_channel_removal()
from vmbus_close_internal() to vmbus_device_release(), since the latter is
always invoked on device_unregister(), whether or not the dev has a driver
loaded.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
Dexuan Cui 64b7faf903 Drivers: hv: vmbus: do sanity check of channel state in vmbus_close_internal()
This fixes an incorrect assumption of channel state in the function.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
Dexuan Cui 63d55b2aeb Drivers: hv: vmbus: serialize process_chn_event() and vmbus_close_internal()
process_chn_event(), running in the tasklet, can race with
vmbus_close_internal() in the case of SMP guest, e.g., when the former is
accessing channel->inbound.ring_buffer, the latter could be freeing the
ring_buffer pages.

To resolve the race, we can serialize them by disabling the tasklet when
the latter is running here.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
K. Y. Srinivasan efc267226b Drivers: hv: vmbus: Get rid of the unused irq variable
The irq we extract from ACPI is not used - we deliver hypervisor
interrupts on a special vector. Make the necessary adjustments.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
K. Y. Srinivasan 4ae9250893 Drivers: hv: vmbus: Use uuid_le_cmp() for comparing GUIDs
Use uuid_le_cmp() for comparing GUIDs.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
K. Y. Srinivasan af3ff643ea Drivers: hv: vmbus: Use uuid_le type consistently
Consistently use uuid_le type in the Hyper-V driver code.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
Olaf Hering ed9ba608e4 Drivers: hv: vss: run only on supported host versions
The Backup integration service on WS2012 has appearently trouble to
negotiate with a guest which does not support the provided util version.
Currently the VSS driver supports only version 5/0. A WS2012 offers only
version 1/x and 3/x, and vmbus_prep_negotiate_resp correctly returns an
empty icframe_vercnt/icmsg_vercnt. But the host ignores that and
continues to send ICMSGTYPE_NEGOTIATE messages. The result are weird
errors during boot and general misbehaviour.

Check the Windows version to work around the host bug, skip hv_vss_init
on WS2012 and older.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:15:05 -08:00
Jake Oshins 3053c76244 drivers:hv: Define the channel type for Hyper-V PCI Express pass-through
This defines the channel type for PCI front-ends in Hyper-V VMs.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:12:21 -08:00
Jake Oshins a108393dbf drivers:hv: Export the API to invoke a hypercall on Hyper-V
This patch exposes the function that hv_vmbus.ko uses to make hypercalls.  This
is necessary for retargeting an interrupt when it is given a new affinity.

Since we are exporting this API, rename the API as it will be visible outside
the hv.c file.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:12:21 -08:00
Jake Oshins 619848bd07 drivers:hv: Export a function that maps Linux CPU num onto Hyper-V proc num
This patch exposes the mapping between Linux CPU number and Hyper-V virtual
processor number.  This is necessary because the hypervisor needs to know which
virtual processors to target when making a mapping in the Interrupt Redirection
Table in the I/O MMU.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:12:21 -08:00
Andrey Smetanin 17efbee8ba drivers/hv: cleanup synic msrs if vmbus connect failed
Before vmbus_connect() synic is setup per vcpu - this means
hypervisor receives writes at synic msr's and probably allocate
hypervisor resources per synic setup.

If vmbus_connect() failed for some reason it's neccessary to cleanup
synic setup by call hv_synic_cleanup() at each vcpu to get a chance
to free allocated resources by hypervisor per synic.

This patch does appropriate cleanup in case of vmbus_connect() failure.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:12:21 -08:00
Olaf Hering b00359642c Drivers: hv: utils: use memdup_user in hvt_op_write
Use memdup_user to handle OOM.

Fixes: 14b50f80c3 ('Drivers: hv: util: introduce hv_utils_transport abstraction')

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:12:21 -08:00
Olaf Hering cdc0c0c94e Drivers: hv: util: catch allocation errors
Catch allocation errors in hvutil_transport_send.

Fixes: 14b50f80c3 ('Drivers: hv: util: introduce hv_utils_transport abstraction')

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:12:21 -08:00
Olaf Hering 3cace4a616 Drivers: hv: utils: run polling callback always in interrupt context
All channel interrupts are bound to specific VCPUs in the guest
at the point channel is created. While currently, we invoke the
polling function on the correct CPU (the CPU to which the channel
is bound to) in some cases we may run the polling function in
a non-interrupt context. This  potentially can cause an issue as the
polling function can be interrupted by the channel callback function.
Fix the issue by running the polling function on the appropriate CPU
at interrupt level. Additional details of the issue being addressed by
this patch are given below:

Currently hv_fcopy_onchannelcallback is called from interrupts and also
via the ->write function of hv_utils. Since the used global variables to
maintain state are not thread safe the state can get out of sync.
This affects the variable state as well as the channel inbound buffer.

As suggested by KY adjust hv_poll_channel to always run the given
callback on the cpu which the channel is bound to. This avoids the need
for locking because all the util services are single threaded and only
one transaction is active at any given point in time.

Additionally, remove the context variable, they will always be the same as
recv_channel.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:12:21 -08:00
K. Y. Srinivasan c0b200cfb0 Drivers: hv: util: Increase the timeout for util services
Util services such as KVP and FCOPY need assistance from daemon's running
in user space. Increase the timeout so we don't prematurely terminate
the transaction in the kernel. Host sets up a 60 second timeout for
all util driver transactions. The host will retry the transaction if it
times out. Set the guest timeout at 30 seconds.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:12:21 -08:00
Sudip Mukherjee 9220e39b5c Drivers: hv: vmbus: fix build warning
We were getting build warning about unused variable "tsc_msr" and
"va_tsc" while building for i386 allmodconfig.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 13:34:50 -08:00
Andrey Smetanin c75efa974e drivers/hv: share Hyper-V SynIC constants with userspace
Moved Hyper-V synic contants from guest Hyper-V drivers private
header into x86 arch uapi Hyper-V header.

Added Hyper-V synic msr's flags into x86 arch uapi Hyper-V header.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-04 16:24:33 +01:00
Dexuan Cui ca1c4b7457 Drivers: hv: vmbus: fix init_vp_index() for reloading hv_netvsc
This fixes the recent commit 3b71107d73b16074afa7658f3f0fcf837aabfe24:
Drivers: hv: vmbus: Further improve CPU affiliation logic

Without the fix, reloading hv_netvsc hangs the guest.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-20 22:44:51 -07:00
Vitaly Kuznetsov f39c4280a3 Drivers: hv: vmbus: use cpu_hotplug_enable/disable
Commit e513229b4c ("Drivers: hv: vmbus: prevent cpu offlining on newer
hypervisors") was altering smp_ops.cpu_disable to prevent CPU offlining.
We can bo better by using cpu_hotplug_enable/disable functions instead of
such hard-coding.

Reported-by: Radim Kr.má  <rkrcmar@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 11:46:44 -07:00
Dexuan Cui 042ab0313b Drivers: hv: vmbus: add a sysfs attr to show the binding of channel/VP
This is useful to analyze performance issue.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 11:44:29 -07:00
K. Y. Srinivasan ca9357bd26 Drivers: hv: vmbus: Implement a clocksource based on the TSC page
The current Hyper-V clock source is based on the per-partition reference counter
and this counter is being accessed via s synthetic MSR - HV_X64_MSR_TIME_REF_COUNT.
Hyper-V has a more efficient way of computing the per-partition reference
counter value that does not involve reading a synthetic MSR. We implement
a time source based on this mechanism.

Tested-by: Vivek Yadav <vyadav@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 11:44:29 -07:00
Viresh Kumar bc609cb47f drivers/hv: Migrate to new 'set-state' interface
Migrate hv driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: devel@linuxdriverproject.org
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 11:44:29 -07:00
Christopher Oo a5cca686ce Drivers: hv_vmbus: Fix signal to host condition
Fixes a bug where previously hv_ringbuffer_read would pass in the old
number of bytes available to read instead of the expected old read index
when calculating when to signal to the host that the ringbuffer is empty.
Since the previous write size is already saved, also changes the
hv_need_to_signal_on_read to use the previously read value rather than
recalculating it.

Signed-off-by: Christopher Oo <t-chriso@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 11:44:29 -07:00
Dexuan Cui 3b71107d73 Drivers: hv: vmbus: Further improve CPU affiliation logic
Keep track of CPU affiliations of sub-channels within the scope of the primary
channel. This will allow us to better distribute the load amongst available
CPUs.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 11:44:28 -07:00
K. Y. Srinivasan 9f01ec5345 Drivers: hv: vmbus: Improve the CPU affiliation for channels
The current code tracks the assigned CPUs within a NUMA node in the context of
the primary channel. So, if we have a VM with a single NUMA node with 8 VCPUs, we may
end up unevenly distributing the channel load. Fix the issue by tracking affiliations
globally.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 11:41:31 -07:00
Jake Oshins 3546448338 drivers:hv: Move MMIO range picking from hyper_fb to hv_vmbus
This patch deletes the logic from hyperv_fb which picked a range of MMIO space
for the frame buffer and adds new logic to hv_vmbus which picks ranges for
child drivers.  The new logic isn't quite the same as the old, as it considers
more possible ranges.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 11:41:31 -07:00
Jake Oshins 7f163a6fd9 drivers:hv: Modify hv_vmbus to search for all MMIO ranges available.
This patch changes the logic in hv_vmbus to record all of the ranges in the
VM's firmware (BIOS or UEFI) that offer regions of memory-mapped I/O space for
use by paravirtual front-end drivers.  The old logic just found one range
above 4GB and called it good.  This logic will find any ranges above 1MB.

It would have been possible with this patch to just use existing resource
allocation functions, rather than keep track of the entire set of Hyper-V
related MMIO regions in VMBus.  This strategy, however, is not sufficient
when the resource allocator needs to be aware of the constraints of a
Hyper-V virtual machine, which is what happens in the next patch in the series.
So this first patch exists to show the first steps in reworking the MMIO
allocation paths for Hyper-V front-end drivers.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-05 11:41:30 -07:00
K. Y. Srinivasan 379e4f756b Drivers: hv: vmbus: Consider ND NIC in binding channels to CPUs
We cycle through all the "high performance" channels to distribute
load across the available CPUs. Process the NetworkDirect as a
high performance device.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:30:44 -07:00
Denis V. Lunev cc2dd4027a mshyperv: fix recognition of Hyper-V guest crash MSR's
Hypervisor Top Level Functional Specification v3.1/4.0 notes that cpuid
(0x40000003) EDX's 10th bit should be used to check that Hyper-V guest
crash MSR's functionality available.

This patch should fix this recognition. Currently the code checks EAX
register instead of EDX.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:30:44 -07:00
Vitaly Kuznetsov 4a54243fc0 Drivers: hv: vmbus: don't send CHANNELMSG_UNLOAD on pre-Win2012R2 hosts
Pre-Win2012R2 hosts don't properly handle CHANNELMSG_UNLOAD and
wait_for_completion() hangs. Avoid sending such request on old hosts.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:29:45 -07:00
Nik Nyby e26009aad0 Drivers: hv: vmbus: fix typo in hv_port_info struct
This fixes a typo: base_flag_bumber to base_flag_number

Signed-off-by: Nik Nyby <nikolas@gnu.org>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:29:45 -07:00
Dan Carpenter 9dd6a06430 hv: util: checking the wrong variable
We don't catch this allocation failure because there is a typo and we
check the wrong variable.

Fixes: 14b50f80c3 ('Drivers: hv: util: introduce hv_utils_transport abstraction')

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:29:45 -07:00
K. Y. Srinivasan b81658cf5d Drivers: hv: vmbus: Permit sending of packets without payload
The guest may have to send a completion packet back to the host.
To support this usage, permit sending a packet without a payload -
we would be only sending the descriptor in this case.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:28:39 -07:00
Alex Ng b6ddeae160 Drivers: hv: balloon: Enable dynamic memory protocol negotiation with Windows 10 hosts
Support Win10 protocol for Dynamic Memory. Thia patch allows guests on Win10 hosts
to hot-add memory even when dynamic memory is not enabled on the guest.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:28:39 -07:00
Vitaly Kuznetsov 25ef06fe27 Drivers: hv: fcopy: dynamically allocate smsg_out in fcopy_send_data()
struct hv_start_fcopy is too big to be on stack on i386, the following
warning is reported:

>> drivers/hv/hv_fcopy.c:159:1: warning: the frame size of 1088 bytes is larger than 1024 bytes [-Wframe-larger-than=]

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:28:38 -07:00
Vitaly Kuznetsov b36fda3397 Drivers: hv: kvp: check kzalloc return value
kzalloc() return value check was accidentally lost in 11bc3a5fa91f:
"Drivers: hv: kvp: convert to hv_utils_transport" commit.

We don't need to reset kvp_transaction.state here as we have the
kvp_timeout_func() timeout function and in case we're in OOM situation
it is preferable to wait.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:28:38 -07:00
Vitaly Kuznetsov 510f7aef65 Drivers: hv: vmbus: prefer 'die' notification chain to 'panic'
current_pt_regs() sometimes returns regs of the userspace process and in
case of a kernel crash this is not what we need to report. E.g. when we
trigger crash with sysrq we see the following:
...
 RIP: 0010:[<ffffffff815b8696>]  [<ffffffff815b8696>] sysrq_handle_crash+0x16/0x20
 RSP: 0018:ffff8800db0a7d88  EFLAGS: 00010246
 RAX: 000000000000000f RBX: ffffffff820a0660 RCX: 0000000000000000
...
at the same time current_pt_regs() give us:
ip=7f899ea7e9e0, ax=ffffffffffffffda, bx=26c81a0, cx=7f899ea7e9e0, ...
These registers come from the userspace process triggered the crash. As we
don't even know which process it was this information is rather useless.

When kernel crash happens through 'die' proper regs are being passed to
all receivers on the die_chain (and panic_notifier_list is being notified
with the string passed to panic() only). If panic() is called manually
(e.g. on BUG()) we won't get 'die' notification so keep the 'panic'
notification reporter as well but guard against double reporting.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:28:38 -07:00
Vitaly Kuznetsov b4370df2b1 Drivers: hv: vmbus: add special crash handler
Full kernel hang is observed when kdump kernel starts after a crash. This
hang happens in vmbus_negotiate_version() function on
wait_for_completion() as Hyper-V host (Win2012R2 in my testing) never
responds to CHANNELMSG_INITIATE_CONTACT as it thinks the connection is
already established. We need to perform some mandatory minimalistic
cleanup before we start new kernel.

Reported-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:28:38 -07:00
Vitaly Kuznetsov d7646eaa76 Drivers: hv: don't do hypercalls when hypercall_page is NULL
At the very late stage of kexec a driver (which are not being unloaded) can
try to post a message or signal an event. This will crash the kernel as we
already did hv_cleanup() and the hypercall page is NULL.

Move all common (between 32 and 64 bit code) declarations to the beginning
of the do_hypercall() function. Unfortunately we have to write the
!hypercall_page check twice to not mix declarations and code.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:25:29 -07:00
Vitaly Kuznetsov 2517281d63 Drivers: hv: vmbus: add special kexec handler
When general-purpose kexec (not kdump) is being performed in Hyper-V guest
the newly booted kernel fails with an MCE error coming from the host. It
is the same error which was fixed in the "Drivers: hv: vmbus: Implement
the protocol for tearing down vmbus state" commit - monitor pages remain
special and when they're being written to (as the new kernel doesn't know
these pages are special) bad things happen. We need to perform some
minimalistic cleanup before booting a new kernel on kexec. To do so we
need to register a special machine_ops.shutdown handler to be executed
before the native_machine_shutdown(). Registering a shutdown notification
handler via the register_reboot_notifier() call is not sufficient as it
happens to early for our purposes. machine_ops is not being exported to
modules (and I don't think we want to export it) so let's do this in
mshyperv.c

The minimalistic cleanup consists of cleaning up clockevents, synic MSRs,
guest os id MSR, and hypercall MSR.

Kdump doesn't require all this stuff as it lives in a separate memory
space.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:25:29 -07:00
Vitaly Kuznetsov 06210b42f3 Drivers: hv: vmbus: remove hv_synic_free_cpu() call from hv_synic_cleanup()
We already have hv_synic_free() which frees all per-cpu pages for all
CPUs, let's remove the hv_synic_free_cpu() call from hv_synic_cleanup()
so it will be possible to do separate cleanup (writing to MSRs) and final
freeing. This is going to be used to assist kexec.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:25:28 -07:00
K. Y. Srinivasan 294409d205 Drivers: hv: vmbus: Allocate ring buffer memory in NUMA aware fashion
Allocate ring buffer memory from the NUMA node assigned to the channel.
Since this is a performance and not a correctness issue, if the node specific
allocation were to fail, fall back and allocate without specifying the node.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-12 16:58:33 -07:00
K. Y. Srinivasan 1f656ff3fd Drivers: hv: vmbus: Implement NUMA aware CPU affinity for channels
Channels/sub-channels can be affinitized to VCPUs in the guest. Implement
this affinity in a way that is NUMA aware. The current protocol distributed
the primary channels uniformly across all available CPUs. The new protocol
is NUMA aware: primary channels are distributed across the available NUMA
nodes while the sub-channels within a primary channel are distributed amongst
CPUs within the NUMA node assigned to the primary channel.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01 10:56:31 +09:00
K. Y. Srinivasan 9c6e64adf2 Drivers: hv: vmbus: Use the vp_index map even for channels bound to CPU 0
Map target_cpu to target_vcpu using the mapping table.
We should use the mapping table to transform guest CPU ID to VP Index
as is done for the non-performance critical channels.
While the value CPU 0 is special and will
map to VP index 0, it is good to be consistent.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01 10:56:31 +09:00
Vitaly Kuznetsov 4e4bd36f97 Drivers: hv: balloon: check if ha_region_mutex was acquired in MEM_CANCEL_ONLINE case
Memory notifiers are being executed in a sequential order and when one of
them fails returning something different from NOTIFY_OK the remainder of
the notification chain is not being executed. When a memory block is being
onlined in online_pages() we do memory_notify(MEM_GOING_ONLINE, ) and if
one of the notifiers in the chain fails we end up doing
memory_notify(MEM_CANCEL_ONLINE, ) so it is possible for a notifier to see
MEM_CANCEL_ONLINE without seeing the corresponding MEM_GOING_ONLINE event.
E.g. when CONFIG_KASAN is enabled the kasan_mem_notifier() is being used
to prevent memory hotplug, it returns NOTIFY_BAD for all MEM_GOING_ONLINE
events. As kasan_mem_notifier() comes before the hv_memory_notifier() in
the notification chain we don't see the MEM_GOING_ONLINE event and we do
not take the ha_region_mutex. We, however, see the MEM_CANCEL_ONLINE event
and unconditionally try to release the lock, the following is observed:

[  110.850927] =====================================
[  110.850927] [ BUG: bad unlock balance detected! ]
[  110.850927] 4.1.0-rc3_bugxxxxxxx_test_xxxx #595 Not tainted
[  110.850927] -------------------------------------
[  110.850927] systemd-udevd/920 is trying to release lock
(&dm_device.ha_region_mutex) at:
[  110.850927] [<ffffffff81acda0e>] mutex_unlock+0xe/0x10
[  110.850927] but there are no more locks to release!

At the same time we can have the ha_region_mutex taken when we get the
MEM_CANCEL_ONLINE event in case one of the memory notifiers after the
hv_memory_notifier() in the notification chain failed so we need to add
the mutex_is_locked() check. In case of MEM_ONLINE we are always supposed
to have the mutex locked.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01 06:38:21 +09:00
Keith Mange 6c4e5f9c9f Drivers: hv: vmbus:Update preferred vmbus protocol version to windows 10.
Add support for Windows 10.

Signed-off-by: Keith Mange <keith.mange@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-01 06:38:21 +09:00
Vitaly Kuznetsov ce59fec836 Drivers: hv: vmbus: distribute subchannels among all vcpus
Primary channels are distributed evenly across all vcpus we have. When the host
asks us to create subchannels it usually makes us num_cpus-1 offers and we are
supposed to distribute the work evenly among the channel itself and all its
subchannels. Make sure they are all assigned to different vcpus.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:19:00 -07:00
Vitaly Kuznetsov f38e7dd723 Drivers: hv: vmbus: move init_vp_index() call to vmbus_process_offer()
We need to call init_vp_index() after we added the channel to the appropriate
list (global or subchannel) to be able to use this information when assigning
the channel to the particular vcpu. To do so we need to move a couple of
functions around. The only real change is the init_vp_index() call. This is a
small refactoring without a functional change.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:19:00 -07:00
Vitaly Kuznetsov 357e836a60 Drivers: hv: vmbus: decrease num_sc on subchannel removal
It is unlikely that that host will ask us to close only one subchannel for a
device but let's be consistent. Do both num_sc++ and num_sc-- with
channel->lock to be on the safe side.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:19:00 -07:00
Vitaly Kuznetsov 8dfd332674 Drivers: hv: vmbus: unify calls to percpu_channel_enq()
Remove some code duplication, no functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:19:00 -07:00
Vitaly Kuznetsov 1959a28e26 Drivers: hv: vmbus: kill tasklets on module unload
Explicitly kill tasklets we create on module unload.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:19:00 -07:00
Vitaly Kuznetsov ffc151f3c8 Drivers: hv: vmbus: do cleanup on all vmbus_open() failure paths
In case there was an error reported in the response to the CHANNELMSG_OPENCHANNEL
call we need to do the cleanup as a vmbus_open() user won't be doing it after
receiving an error. The cleanup should be done on all failure paths. We also need
to avoid returning open_info->response.open_result.status as the return value as
all other errors we return from vmbus_open() are -EXXX and vmbus_open() callers
are not supposed to analyze host error codes.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:19:00 -07:00
K. Y. Srinivasan 2db84eff12 Drivers: hv: vmbus: Implement the protocol for tearing down vmbus state
Implement the protocol for tearing down the monitor state established with
the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:18:24 -07:00
Dexuan Cui 813c5b7958 hv: vmbus_free_channels(): remove the redundant free_channel()
free_channel() has been invoked in
vmbus_remove() -> hv_process_channel_removal(), or vmbus_remove() ->
... -> vmbus_close_internal() -> hv_process_channel_removal().

We also change to use list_for_each_entry_safe(), because the entry
is removed in hv_process_channel_removal().

This patch fixes a bug in the vmbus unload path.

Thank Dan Carpenter for finding the issue!

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:18:23 -07:00
Vitaly Kuznetsov 096c605feb Drivers: hv: vmbus: unregister panic notifier on module unload
Commit 96c1d0581d ("Drivers: hv: vmbus: Add
support for VMBus panic notifier handler") introduced
atomic_notifier_chain_register() call on module load. We also need to call
atomic_notifier_chain_unregister() on module unload as otherwise the following
crash is observed when we bring hv_vmbus back:

[   39.788877] BUG: unable to handle kernel paging request at ffffffffa00078a8
[   39.788877] IP: [<ffffffff8109d63f>] notifier_call_chain+0x3f/0x80
...
[   39.788877] Call Trace:
[   39.788877]  [<ffffffff8109de7d>] __atomic_notifier_call_chain+0x5d/0x90
...
[   39.788877]  [<ffffffff8109d788>] ? atomic_notifier_chain_register+0x38/0x70
[   39.788877]  [<ffffffff8109d767>] ? atomic_notifier_chain_register+0x17/0x70
[   39.788877]  [<ffffffffa002814f>] hv_acpi_init+0x14f/0x1000 [hv_vmbus]
[   39.788877]  [<ffffffff81002144>] do_one_initcall+0xd4/0x210

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:18:23 -07:00
Vitaly Kuznetsov e4ecb41cf9 Drivers: hv: vmbus: introduce vmbus_acpi_remove
In case we do request_resource() in vmbus_acpi_add() we need to tear it down
to be able to load the driver again. Otherwise the following crash in observed
when hv_vmbus unload/load sequence is performed on a Generation2 instance:

[   38.165701] BUG: unable to handle kernel paging request at ffffffffa00075a0
[   38.166315] IP: [<ffffffff8107dc5f>] __request_resource+0x2f/0x50
[   38.166315] PGD 1f34067 PUD 1f35063 PMD 3f723067 PTE 0
[   38.166315] Oops: 0000 [#1] SMP
[   38.166315] Modules linked in: hv_vmbus(+) [last unloaded: hv_vmbus]
[   38.166315] CPU: 0 PID: 267 Comm: modprobe Not tainted 3.19.0-rc5_bug923184+ #486
[   38.166315] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v1.0 11/26/2012
[   38.166315] task: ffff88003f401cb0 ti: ffff88003f60c000 task.ti: ffff88003f60c000
[   38.166315] RIP: 0010:[<ffffffff8107dc5f>]  [<ffffffff8107dc5f>] __request_resource+0x2f/0x50
[   38.166315] RSP: 0018:ffff88003f60fb58  EFLAGS: 00010286

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:18:23 -07:00
Vitaly Kuznetsov 7c95912758 Drivers: hv: utils: unify driver registration reporting
Unify driver registration reporting and move it to debug level as normally daemons write to syslog themselves
and these kernel messages are useless.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:42 -07:00
Vitaly Kuznetsov a4d1ee5b02 Drivers: hv: fcopy: full handshake support
Introduce FCOPY_VERSION_1 to support kernel replying to the negotiation
message with its own version.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:42 -07:00
Vitaly Kuznetsov cd8dc05485 Drivers: hv: vss: full handshake support
Introduce VSS_OP_REGISTER1 to support kernel replying to the negotiation
message with its own version.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:41 -07:00
Vitaly Kuznetsov 11bc3a5fa9 Drivers: hv: kvp: convert to hv_utils_transport
Convert to hv_utils_transport to support both netlink and /dev/vmbus/hv_kvp communication methods.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:41 -07:00
Vitaly Kuznetsov c7e490fc23 Drivers: hv: fcopy: convert to hv_utils_transport
Unify the code with the recently introduced hv_utils_transport. Netlink
communication is disabled for fcopy.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:41 -07:00
Vitaly Kuznetsov 6472f80a2e Drivers: hv: vss: convert to hv_utils_transport
Convert to hv_utils_transport to support both netlink and /dev/vmbus/hv_vss communication methods.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:41 -07:00
Vitaly Kuznetsov 14b50f80c3 Drivers: hv: util: introduce hv_utils_transport abstraction
The intention is to make KVP/VSS drivers work through misc char devices.
Introduce an abstraction for kernel/userspace communication to make the
migration smoother. Transport operational mode (netlink or char device)
is determined by the first received message. To support driver upgrades
the switch from netlink to chardev operational mode is supported.

Every hv_util daemon is supposed to register 2 callbacks:
1) on_msg() to get notified when the userspace daemon sent a message;
2) on_reset() to get notified when the userspace daemon drops the connection.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:41 -07:00
Vitaly Kuznetsov 3f0dccf86c Drivers: hv: fcopy: set .owner reference for file operations
Get an additional reference otherwise a crash is observed when hv_utils module is being unloaded while
fcopy daemon is still running. .owner gives us an additional reference when
someone holds a descriptor for the device.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:41 -07:00
Vitaly Kuznetsov 4c93ccccf4 Drivers: hv: fcopy: switch to using the hvutil_device_state state machine
Switch to using the hvutil_device_state state machine from using 3 different state variables:
fcopy_transaction.active, opened, and in_hand_shake.

State transitions are:
-> HVUTIL_DEVICE_INIT when driver loads or on device release
-> HVUTIL_READY if the handshake was successful
-> HVUTIL_HOSTMSG_RECEIVED when there is a non-negotiation message from the host
-> HVUTIL_USERSPACE_REQ after userspace daemon read the message
   -> HVUTIL_USERSPACE_RECV after/if userspace has replied
-> HVUTIL_READY after we respond to the host
-> HVUTIL_DEVICE_DYING on driver unload

In hv_fcopy_onchannelcallback() process ICMSGTYPE_NEGOTIATE messages even when
the userspace daemon is disconnected, otherwise we can make the host think
we don't support FCOPY and disable the service completely.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:41 -07:00
Vitaly Kuznetsov 086a6f68d6 Drivers: hv: vss: switch to using the hvutil_device_state state machine
Switch to using the hvutil_device_state state machine from using kvp_transaction.active.

State transitions are:
-> HVUTIL_DEVICE_INIT when driver loads or on device release
-> HVUTIL_READY if the handshake was successful
-> HVUTIL_HOSTMSG_RECEIVED when there is a non-negotiation message from the host
-> HVUTIL_USERSPACE_REQ after we sent the message to the userspace daemon
   -> HVUTIL_USERSPACE_RECV after/if the userspace daemon has replied
-> HVUTIL_READY after we respond to the host
-> HVUTIL_DEVICE_DYING on driver unload

In hv_vss_onchannelcallback() process ICMSGTYPE_NEGOTIATE messages even when
the userspace daemon is disconnected, otherwise we can make the host think
we don't support VSS and disable the service completely.

Unfortunately there is no good way we can figure out that the userspace daemon
has died (unless we start treating all timeouts as such), add a protection
against processing new VSS_OP_REGISTER messages while being in the middle of a
transaction (HVUTIL_USERSPACE_REQ or HVUTIL_USERSPACE_RECV state).

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:41 -07:00
Vitaly Kuznetsov 97bf16cd30 Drivers: hv: kvp: switch to using the hvutil_device_state state machine
Switch to using the hvutil_device_state state machine from using 2 different state variables: kvp_transaction.active and
in_hand_shake.

State transitions are:
-> HVUTIL_DEVICE_INIT when driver loads or on device release
-> HVUTIL_READY if the handshake was successful
-> HVUTIL_HOSTMSG_RECEIVED when there is a non-negotiation message from the host
-> HVUTIL_USERSPACE_REQ after we sent the message to the userspace daemon
   -> HVUTIL_USERSPACE_RECV after/if the userspace daemon has replied
-> HVUTIL_READY after we respond to the host
-> HVUTIL_DEVICE_DYING on driver unload

In hv_kvp_onchannelcallback() process ICMSGTYPE_NEGOTIATE messages even when
the userspace daemon is disconnected, otherwise we can make the host think
we don't support KVP and disable the service completely.

Unfortunately there is no good way we can figure out that the userspace daemon
has died (unless we start treating all timeouts as such). In case the daemon
restarts we skip the negotiation procedure (so the daemon is supposed to has
the same version). This behavior is unchanged from in_handshake approach.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:41 -07:00
Vitaly Kuznetsov 636c88da6d Drivers: hv: util: introduce state machine for util drivers
KVP/VSS/FCOPY drivers work in fully serialized mode: we wait till userspace
daemon registers, wait for a message from the host, send this message to the
daemon, get the reply, send it back to host, wait for another message.
Introduce enum hvutil_device_state to represend this state in all 3 drivers.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:41 -07:00
Vitaly Kuznetsov 1d072339fa Drivers: hv: fcopy: rename fcopy_work -> fcopy_timeout_work
'fcopy_work' (and fcopy_work_func) is a misnomer as it sounds like we expect
this useful work to happen and in reality it is just an emergency escape when
timeout happens.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:40 -07:00
Vitaly Kuznetsov 68c8b39a0d Drivers: hv: kvp: rename kvp_work -> kvp_timeout_work
'kvp_work' (and kvp_work_func) is a misnomer as it sounds like we expect
this useful work to happen and in reality it is just an emergency escape when
timeout happens.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:40 -07:00
Vitaly Kuznetsov 38c06c29ba Drivers: hv: vss: process deferred messages when we complete the transaction
In theory, the host is not supposed to issue any requests before be reply to
the previous one. In KVP we, however, support the following scenarios:
1) A message was received before userspace daemon registered;
2) A message was received while the previous one is still being processed.
In VSS we support only the former. Add support for the later, use
hv_poll_channel() to do the job.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:40 -07:00
Vitaly Kuznetsov 242f31221d Drivers: hv: fcopy: process deferred messages when we complete the transaction
In theory, the host is not supposed to issue any requests before be reply to
the previous one. In KVP we, however, support the following scenarios:
1) A message was received before userspace daemon registered;
2) A message was received while the previous one is still being processed.
In FCOPY we support only the former. Add support for the later, use
hv_poll_channel() to do the job.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:40 -07:00
Vitaly Kuznetsov 8efe78fdb1 Drivers: hv: kvp: move poll_channel() to hyperv_vmbus.h
Move poll_channel() to hyperv_vmbus.h and make it inline and rename it to hv_poll_channel() so it can be reused
in other hv_util modules.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:40 -07:00
Vitaly Kuznetsov 5fa97480b9 Drivers: hv: kvp: reset kvp_context
We set kvp_context when we want to postpone receiving a packet from vmbus due
to the previous transaction being unfinished. We, however, never reset this
state, all consequent kvp_respond_to_host() calls will result in poll_channel()
calling hv_kvp_onchannelcallback(). This doesn't cause real issues as:
1) Host is supposed to serialize transactions as well
2) If no message is pending vmbus_recvpacket() will return 0 recvlen.
This is just a cleanup.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:40 -07:00
Vitaly Kuznetsov 3647a83d9d Drivers: hv: util: move kvp/vss function declarations to hyperv_vmbus.h
These declarations are internal to hv_util module and hv_fcopy_* declarations
already reside there.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:17:40 -07:00
Vitaly Kuznetsov 797f88c987 Drivers: hv: hv_balloon: correctly handle num_pages>INT_MAX case
balloon_wrk.num_pages is __u32 and it comes from host in struct dm_balloon
where it is also __u32. We, however, use 'int' in balloon_up() and in case
we happen to receive num_pages>INT_MAX request we'll end up allocating zero
pages as 'num_pages < alloc_unit' check in alloc_balloon_pages() will pass.
Change num_pages type to unsigned int.

In real life ballooning request come with num_pages in [512, 32768] range so
this is more a future-proof/cleanup.

Reported-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-03 16:20:12 +02:00
Vitaly Kuznetsov ba0c444153 Drivers: hv: hv_balloon: correctly handle val.freeram<num_pages case
'Drivers: hv: hv_balloon: refuse to balloon below the floor' fix does not
correctly handle the case when val.freeram < num_pages as val.freeram is
__kernel_ulong_t and the 'val.freeram - num_pages' value will be a huge
positive value instead of being negative.

Usually host doesn't ask us to balloon more than val.freeram but in case
he have a memory hog started after we post the last pressure report we
can get into troubles.

Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-03 16:20:12 +02:00
Haiyang Zhang e1c0d82dab hv_vmbus: Add gradually increased delay for retries in vmbus_post_msg()
Most of the retries can be done within a millisecond successfully, so we
sleep 1ms before the first retry, then gradually increase the retry
interval to 2^n with max value of 2048ms. Doing so, we will have shorter
overall delay time, because most of the cases succeed within 1-2 attempts.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-03 16:18:02 +02:00
Vitaly Kuznetsov 0a1a86ac04 Drivers: hv: hv_balloon: survive ballooning request with num_pages=0
... and simplify alloc_balloon_pages() interface by removing redundant
alloc_error from it.

If we happen to enter balloon_up() with balloon_wrk.num_pages = 0 we will enter
infinite 'while (!done)' loop as alloc_balloon_pages() will be always returning
0 and not setting alloc_error. We will also be sending a meaningless message to
the host on every iteration.

The 'alloc_unit == 1 && alloc_error -> num_ballooned == 0' change and
alloc_error elimination requires a special comment. We do alloc_balloon_pages()
with 2 different alloc_unit values and there are 4 different
alloc_balloon_pages() results, let's check them all.

alloc_unit = 512:
1) num_ballooned = 0, alloc_error = 0: we do 'alloc_unit=1' and retry pre- and
  post-patch.
2) num_ballooned > 0, alloc_error = 0: we check 'num_ballooned == num_pages'
  and act accordingly,  pre- and post-patch.
3) num_ballooned > 0, alloc_error > 0: we report this chunk and remain within
  the loop, no changes here.
4) num_ballooned = 0, alloc_error > 0: we do 'alloc_unit=1' and retry pre- and
  post-patch.

alloc_unit = 1:
1) num_ballooned = 0, alloc_error = 0: this can happen in two cases: when we
  passed 'num_pages=0' to alloc_balloon_pages() or when there was no space in
  bl_resp to place a single response. The second option is not possible as
  bl_resp is of PAGE_SIZE size and single response 'union dm_mem_page_range' is
  8 bytes, but the first one is (in theory, I think that Hyper-V host never
  places such requests). Pre-patch code loops forever, post-patch code sends
  a reply with more_pages = 0 and finishes.
2) num_ballooned > 0, alloc_error = 0: we ran out of space in bl_resp, we
  report partial success and remain within the loop, no changes pre- and
  post-patch.
3) num_ballooned > 0, alloc_error > 0: pre-patch code finishes, post-patch code
  does one more try and if there is no progress (we finish with
  'num_ballooned = 0') we finish. So we try a bit harder with this patch.
4) num_ballooned = 0, alloc_error > 0: both pre- and post-patch code enter
 'more_pages = 0' branch and finish.

So this patch has two real effects:
1) We reply with an empty response to 'num_pages=0' request.
2) We try a bit harder on alloc_unit=1 allocations (and reply with an empty
   tail reply in case we fail).

An empty reply should be supported by host as we were able to send it even with
pre-patch code when we were not able to allocate a single page.

Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-03 16:18:02 +02:00
Vitaly Kuznetsov 7fb0e1a650 Drivers: hv: hv_balloon: eliminate jumps in piecewiese linear floor function
Commit 79208c57da ("Drivers: hv: hv_balloon: Make adjustments in computing
the floor") was inacurate as it introduced a jump in our piecewiese linear
'floor' function:

At 2048MB we have:
Left limit:
104 + 2048/8 = 360
Right limit:
256 + 2048/16 = 384 (so the right value is 232)

We now have to make an adjustment at 8192 boundary:
232 + 8192/16 = 744
512 + 8192/32 = 768 (so the right value is 488)

Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-03 16:18:02 +02:00
Vitaly Kuznetsov d6cbd2c3a3 Drivers: hv: hv_balloon: do not online pages in offline blocks
Currently we add memory in 128Mb blocks but the request from host can be
aligned differently. In such case we add a partially backed block and
when this block goes online we skip onlining pages which are not backed
(hv_online_page() callback serves this purpose). When we receive next
request for the same host add region we online pages which were not backed
before with hv_bring_pgs_online(). However, we don't check if the the block
in question was onlined and online this tail unconditionally. This is bad as
we avoid all online_pages() logic: these pages are not accounted, we don't
send notifications (and hv_balloon is not the only receiver of them),...
And, first of all, nobody asked as to online these pages. Solve the issue by
checking if the last previously backed page was onlined and onlining the tail
only in case it was.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-03 16:18:02 +02:00
Dexuan Cui aadc3780f3 hv: remove the per-channel workqueue
It's not necessary any longer, since we can safely run the blocking
message handlers in vmbus_connection.work_queue now.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-03 16:18:02 +02:00
Dexuan Cui d43e2fe7da hv: don't schedule new works in vmbus_onoffer()/vmbus_onoffer_rescind()
Since the 2 fucntions can safely run in vmbus_connection.work_queue without
hang, we don't need to schedule new work items into the per-channel workqueue.

Actally we can even remove the per-channel workqueue now -- we'll do it
in the next patch.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-03 16:18:02 +02:00
Dexuan Cui 652594c7df hv: run non-blocking message handlers in the dispatch tasklet
A work item in vmbus_connection.work_queue can sleep, waiting for a new
host message (usually it is some kind of "completion" message). Currently
the new message will be handled in the same workqueue, but since work items
in the workqueue is serialized, we actually have no chance to handle
the new message if the current work item is sleeping -- as as result, the
current work item will hang forever.

K. Y. has posted the below fix to resolve the issue:
Drivers: hv: vmbus: Perform device register in the per-channel work element

Actually we can simplify the fix by directly running non-blocking message
handlers in the dispatch tasklet (inspired by K. Y.).

This patch is the fundamental change. The following 2 patches will simplify
the message offering and rescind-offering handling a lot.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-03 16:18:01 +02:00
K. Y. Srinivasan 73cffdb65e Drivers: hv: vmbus: Don't wait after requesting offers
Don't wait after sending request for offers to the host. This wait is
unnecessary and simply adds 5 seconds to the boot time.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-26 23:51:14 +01:00
K. Y. Srinivasan 5f5cc81733 Drivers: hv: vmbus: Fix a siganlling host signalling issue
Handle the case when the write to the ringbuffer fails. In this case,
unconditionally signal the host. Since we may have deferred signalling
the host based on the kick_q parameter, signalling the host
unconditionally in this case deals with the issue.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25 11:53:55 +01:00
K. Y. Srinivasan b3a19b36ad Drivers: hv: vmbus: Export the vmbus_sendpacket_pagebuffer_ctl()
Export the vmbus_sendpacket_pagebuffer_ctl() interface. This export will be
used by the netvsc driver.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25 11:53:55 +01:00
K. Y. Srinivasan f2eddbc9f1 Drivers: hv: vmbus: Fix a bug in rescind processing in vmbus_close_internal()
When a channel has been rescinded, the close operation is a noop.
Restructure the code so we deal with the rescind condition after
we properly cleanup the channel. I would like to thank
Dexuan Cui <decui@microsoft.com> for observing this problem.
The current code leaks memory when the channel is rescinded.

The current char-next branch is broken and this patch fixes
the bug.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25 11:53:54 +01:00
Dan Carpenter 177757423f hv: vmbus: missing curly braces in vmbus_process_offer()
The indenting makes it clear that there were curly braces intended here.

Fixes: 2dd37cb815 ('Drivers: hv: vmbus: Handle both rescind and offer messages in the same context')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25 11:53:54 +01:00
Nick Meier 5ef5b6927f Drivers: hv: vmbus: Correcting truncation error for constant HV_CRASH_CTL_CRASH_NOTIFY
HV_CRASH_CTL_CRASH_NOTIFY is a 64 bit number.  Depending on the usage context,
the value may be truncated. This patch is in response from the following
email from Wu Fengguang <fengguang.wu@intel.com>:

    From: Wu Fengguang <fengguang.wu@intel.com>
    Subject:  [char-misc:char-misc-testing 25/45] drivers/hv/vmbus_drv.c:67:9: sparse:
              constant 0x8000000000000000 is so big it is unsigned long

    tree:   git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git char-misc-testing
    head:   b3de8e3719
    commit: 96c1d0581d [25/45] Drivers: hv: vmbus: Add support for VMBus panic notifier handler
    reproduce:
      # apt-get install sparse
      git checkout 96c1d0581d
      make ARCH=x86_64 allmodconfig
      make C=1 CF=-D__CHECK_ENDIAN__

    sparse warnings: (new ones prefixed by >>)

    drivers/hv/vmbus_drv.c:67:9: sparse: constant 0x8000000000000000 is so big it is unsigned long
    ...

Signed-off-by: Nick Meier <nmeier@microsoft.com>
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25 11:53:54 +01:00
Vitaly Kuznetsov 5abbbb75d7 Drivers: hv: hv_balloon: don't lose memory when onlining order is not natural
Memory blocks can be onlined in random order. When this order is not natural
some memory pages are not onlined because of the redundant check in
hv_online_page().

Here is a real world scenario:
1) Host tries to hot-add the following (process_hot_add):
  pg_start=rg_start=0x48000, pfn_cnt=111616, rg_size=262144

2) This results in adding 4 memory blocks:
[  109.057866] init_memory_mapping: [mem 0x48000000-0x4fffffff]
[  114.102698] init_memory_mapping: [mem 0x50000000-0x57ffffff]
[  119.168039] init_memory_mapping: [mem 0x58000000-0x5fffffff]
[  124.233053] init_memory_mapping: [mem 0x60000000-0x67ffffff]
The last one is incomplete but we have special has->covered_end_pfn counter to
avoid onlining non-backed frames and hv_bring_pgs_online() function to bring
them online later on.

3) Now we have 4 offline memory blocks: /sys/devices/system/memory/memory9-12
$ for f in /sys/devices/system/memory/memory*/state; do echo $f `cat $f`; done | grep -v onlin
/sys/devices/system/memory/memory10/state offline
/sys/devices/system/memory/memory11/state offline
/sys/devices/system/memory/memory12/state offline
/sys/devices/system/memory/memory9/state offline

4) We bring them online in non-natural order:
$grep MemTotal /proc/meminfo
MemTotal:         966348 kB
$echo online > /sys/devices/system/memory/memory12/state && grep MemTotal /proc/meminfo
MemTotal:        1019596 kB
$echo online > /sys/devices/system/memory/memory11/state && grep MemTotal /proc/meminfo
MemTotal:        1150668 kB
$echo online > /sys/devices/system/memory/memory9/state && grep MemTotal /proc/meminfo
MemTotal:        1150668 kB

As you can see memory9 block gives us zero additional memory. We can also
observe a huge discrepancy between host- and guest-reported memory sizes.

The root cause of the issue is the redundant pg >= covered_start_pfn check (and
covered_start_pfn advancing) in hv_online_page(). When upper memory block in
being onlined before the lower one (memory12 and memory11 in the above case) we
advance the covered_start_pfn pointer and all memory9 pages do not pass the
check. If the assumption that host always gives us requests in sequential order
and pg_start always equals rg_start when the first request for the new HA
region is received (that's the case in my testing) is correct than we can get
rid of covered_start_pfn and pg >= start_pfn check in hv_online_page() is
sufficient.

The current char-next branch is broken and this patch fixes
the bug.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25 11:53:54 +01:00
Vitaly Kuznetsov f3f6eb8087 Drivers: hv: hv_balloon: keep locks balanced on add_memory() failure
When add_memory() fails the following BUG is observed:
[  743.646107] hv_balloon: hot_add memory failed error is -17
[  743.679973]
[  743.680930] =====================================
[  743.680930] [ BUG: bad unlock balance detected! ]
[  743.680930] 3.19.0-rc5_bug1131426+ #552 Not tainted
[  743.680930] -------------------------------------
[  743.680930] kworker/0:2/255 is trying to release lock (&dm_device.ha_region_mutex) at:
[  743.680930] [<ffffffff81aae5fe>] mutex_unlock+0xe/0x10
[  743.680930] but there are no more locks to release!

This happens as we don't acquire ha_region_mutex and hot_add_req() expects us
to as it does unconditional mutex_unlock(). Acquire the lock on the error path.

The current char-next branch is broken and this patch fixes
the bug.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25 11:53:54 +01:00
K. Y. Srinivasan fde25d25db Drivers: hv: vmbus: Perform device register in the per-channel work element
This patch is a continuation of the rescind handling cleanup work. We cannot
block in the global message handling work context especially if we are blocking
waiting for the host to wake us up. I would like to thank
Dexuan Cui <decui@microsoft.com> for observing this problem.

The current char-next branch is broken and this patch fixes
the bug.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25 11:53:53 +01:00
kbuild test robot ed99d846f1 mei: bus: () can be static
drivers/hv/vmbus_drv.c:51:5: sparse: symbol 'hyperv_panic_event' was not declared. Should it be static?
drivers/hv/vmbus_drv.c:51:5: sparse: symbol 'hyperv_panic_event' was not declared. Should it be static?
drivers/hv/vmbus_drv.c:51:5: sparse: symbol 'hyperv_panic_event' was not declared. Should it be static?
drivers/hv/vmbus_drv.c:51:5: sparse: symbol 'hyperv_panic_event' was not declared. Should it be static?

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 21:43:37 -08:00
K. Y. Srinivasan e9395e3f89 Drivers: hv: vmbus: Suport an API to send packet with additional control
Implement an API that gives additional control on the what VMBUS flags will be
set as well as if the host needs to be signalled. This API will be
useful for clients that want to batch up requests to the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:31:47 -08:00
K. Y. Srinivasan 87e93d6170 Drivers: hv: vmbus: Suport an API to send pagebuffers with additional control
Implement an API for sending pagebuffers that gives more control to the client
in terms of setting the vmbus flags as well as deciding when to
notify the host. This will be useful for enabling batch processing.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:31:47 -08:00
K. Y. Srinivasan a13e8bbe85 Drivers: hv: vmbus: Use a round-robin algorithm for picking the outgoing channel
The current algorithm for picking an outgoing channel was not distributing
the load well. Implement a simple round-robin scheme to ensure good
distribution of the outgoing traffic.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:31:47 -08:00
Nick Meier 96c1d0581d Drivers: hv: vmbus: Add support for VMBus panic notifier handler
Hyper-V allows a guest to notify the Hyper-V host that a panic
condition occured.  This notification can include up to five 64
bit values.  These 64 bit values are written into crash MSRs.
Once the data has been written into the crash MSRs, the host is
then notified by writing into a Crash Control MSR.  On the Hyper-V
host, the panic notification data is captured in the Windows Event
log as a 18590 event.

Crash MSRs are defined in appendix H of the Hypervisor Top Level
Functional Specification.  At the time of this patch, v4.0 is the
current functional spec.  The URL for the v4.0 document is:

http://download.microsoft.com/download/A/B/4/AB43A34E-BDD0-4FA6-BDEF-79EEF16E880B/Hypervisor Top Level Functional Specification v4.0.docx

Signed-off-by: Nick Meier <nmeier@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:31:47 -08:00
Vitaly Kuznetsov 530d15b907 Drivers: hv: hv_balloon: refuse to balloon below the floor
When host asks us to balloon up we need to be sure we're not committing suicide
by overballooning. Use already existent 'floor' metric as our lowest possible
value for free ram.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:31:47 -08:00
Vitaly Kuznetsov 549fd280b1 Drivers: hv: hv_balloon: report offline pages as being used
When hot-added memory pages are not brought online or when some memory blocks
are sent offline the subsequent ballooning process kills the guest with OOM
killer. This happens as we don't report these pages as neither used nor free
and apparently host algorithm considers them as being unused. Keep track of
all online/offline operations and report all currently offline pages as being
used so host won't try to balloon them out.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:31:47 -08:00
Vitaly Kuznetsov b05d8d9ef5 Drivers: hv: hv_balloon: eliminate the trylock path in acquire/release_region_mutex
When many memory regions are being added and automatically onlined the
following lockup is sometimes observed:

INFO: task udevd:1872 blocked for more than 120 seconds.
...
Call Trace:
 [<ffffffff816ec0bc>] schedule_timeout+0x22c/0x350
 [<ffffffff816eb98f>] wait_for_common+0x10f/0x160
 [<ffffffff81067650>] ? default_wake_function+0x0/0x20
 [<ffffffff816eb9fd>] wait_for_completion+0x1d/0x20
 [<ffffffff8144cb9c>] hv_memory_notifier+0xdc/0x120
 [<ffffffff816f298c>] notifier_call_chain+0x4c/0x70
...

When several memory blocks are going online simultaneously we got several
hv_memory_notifier() trying to acquire the ha_region_mutex. When this mutex is
being held by hot_add_req() all these competing acquire_region_mutex() do
mutex_trylock, fail, and queue themselves into wait_for_completion(..). However
when we do complete() from release_region_mutex() only one of them wakes up.
This could be solved by changing complete() -> complete_all() memory onlining
can be delayed as well, in that case we can still get several
hv_memory_notifier() runners at the same time trying to grab the mutex.
Only one of them will succeed and the others will hang for forever as
complete() is not being called. We don't see this issue often because we have
5sec onlining timeout in hv_mem_hot_add() and usually all udev events arrive
in this time frame.

Get rid of the trylock path, waiting on the mutex is supposed to provide the
required serialization.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:31:47 -08:00
K. Y. Srinivasan 37f492ce81 Drivers: hv: vmbus: Get rid of some unnecessary messages
Currently we log messages when either we are not able to map an ID to a
channel or when the channel does not have a callback associated
(in the channel interrupt handling path). These messages don't add
any value, get rid of them.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:31:02 -08:00
K. Y. Srinivasan 5380b383ba Drivers: hv: util: On device remove, close the channel after de-initializing the service
When the offer is rescinded, vmbus_close() can free up the channel;
deinitialize the service before closing the channel.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:31:02 -08:00
K. Y. Srinivasan 5b1e5b5307 Drivers: hv: vmbus: Remove the channel from the channel list(s) on failure
Properly rollback state in vmbus_pocess_offer() in the failure paths.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:31:02 -08:00
K. Y. Srinivasan 2dd37cb815 Drivers: hv: vmbus: Handle both rescind and offer messages in the same context
Execute both ressind and offer messages in the same work context. This serializes these
operations and naturally addresses the various corner cases.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:31:02 -08:00
K. Y. Srinivasan ed6cfcc5fd Drivers: hv: vmbus: Introduce a function to remove a rescinded offer
In response to a rescind message, we need to remove the channel and the
corresponding device. Cleanup this code path by factoring out the code
to remove a channel.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:31:02 -08:00
K. Y. Srinivasan d15a0301c4 Drivers: hv: vmbus: Properly handle child device remove
Handle the case when the device may be removed when the device has no driver
attached to it.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:31:02 -08:00
K. Y. Srinivasan 04653a009a Drivers: hv: vmbus: Add support for the NetworkDirect GUID
NetworkDirect is a service that supports guest RDMA.
Define the GUID for this service.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:30:08 -08:00
K. Y. Srinivasan 40384e4bbe Drivers: hv: vmbus: Fix a bug in the error path in vmbus_open()
Correctly rollback state if the failure occurs after we have handed over
the ownership of the buffer to the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:30:08 -08:00
Nicholas Mc Guire b057b3ad16 hv: hv_balloon: match var type to return type of wait_for_completion
return type of wait_for_completion_timeout is unsigned long not int, this
patch changes the type of t from int to unsigned long.

Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:30:08 -08:00
Nicholas Mc Guire 51e5181d20 hv: channel_mgmt: match var type to return type of wait_for_completion
return type of wait_for_completion_timeout is unsigned long not int, this
patch changes the type of t from int to unsigned long.

Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-01 19:30:08 -08:00