SPAPR_MEMORY_BLOCK_SIZE is logically a difference in memory addresses, and
hence of type hwaddr which is 64-bit. Previously it wasn't marked as such
which means that it could be treated as 32-bit. That will work in some
circumstances but if multiplied by another 32-bit value it could lead to
a 32-bit overflow and an incorrect result.
One specific instance of this in spapr_lmb_dt_populate() was spotted by
Coverity (CID 1399145).
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Introduce a new spapr_cap SPAPR_CAP_CCF_ASSIST to be used to indicate
the requirement for a hw-assisted version of the count cache flush
workaround.
The count cache flush workaround is a software workaround which can be
used to flush the count cache on context switch. Some revisions of
hardware may have a hardware accelerated flush, in which case the
software flush can be shortened. This cap is used to set the
availability of such hardware acceleration for the count cache flush
routine.
The availability of such hardware acceleration is indicated by the
H_CPU_CHAR_BCCTR_FLUSH_ASSIST flag being set in the characteristics
returned from the KVM_PPC_GET_CPU_CHAR ioctl.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Message-Id: <20190301031912.28809-2-sjitindarsingh@gmail.com>
[dwg: Small style fixes]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The spapr_cap SPAPR_CAP_IBS is used to indicate the level of capability
for mitigations for indirect branch speculation. Currently the available
values are broken (default), fixed-ibs (fixed by serialising indirect
branches) and fixed-ccd (fixed by diabling the count cache).
Introduce a new value for this capability denoted workaround, meaning that
software can work around the issue by flushing the count cache on
context switch. This option is available if the hypervisor sets the
H_CPU_BEHAV_FLUSH_COUNT_CACHE flag in the cpu behaviours returned from
the KVM_PPC_GET_CPU_CHAR ioctl.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Message-Id: <20190301031912.28809-1-sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Add spapr_cap SPAPR_CAP_LARGE_DECREMENTER to be used to control the
availability of the large decrementer for a guest.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Message-Id: <20190301024317.22137-1-sjitindarsingh@gmail.com>
[dwg: Trivial style fix]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Hotplugging PHBs is a machine-level operation, but PHBs reside on the
main system bus, so we register spapr machine as the handler for the
main system bus.
Provide the usual pre-plug, plug and unplug-request handlers.
Move the checking of the PHB index to the pre-plug handler. It is okay
to do that and assert in the realize function because the pre-plug
handler is always called, even for the oldest machine types we support.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
(Fixed interrupt controller phandle in "interrupt-map" and
TCE table size in "ibm,dma-window" FDT fragment, Greg Kurz)
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155059672926.1466090.13612804072190051439.stgit@bahia.lab.toulouse-stg.fr.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155059670389.1466090.10015601248906623076.stgit@bahia.lab.toulouse-stg.fr.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155059666839.1466090.3833376527523126752.stgit@bahia.lab.toulouse-stg.fr.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155059666331.1466090.6766540766297333313.stgit@bahia.lab.toulouse-stg.fr.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The HW relies on LPCR:HR along with the PATE to determine whether
to use Radix or Hash mode. In fact it uses LPCR:HR more commonly
than the PATE.
For us, it's also more efficient to do so, especially since unlike
the HW we do not maintain a cache of the current PATE and HV PATE
in a generic place.
Prepare the grounds for that by ensuring that LPCR:HR is set
properly on SPAPR machines.
Another option would have been to use a callback to get the PATE
but this gets messy when implementing bare metal support, it's
much simpler (and faster) to use LPCR.
Since existing migration streams may not have it, fix it up in
spapr_post_load() as well based on the pseudo-PATE entry that
we keep.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190215170029.15641-2-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
On ppc hosts, hypervisor shares following system attributes
- /proc/device-tree/system-id
- /proc/device-tree/model
with a guest. This could lead to information leakage and misuse.[*]
Add machine attributes to control such system information exposure
to a guest.
[*] https://wiki.openstack.org/wiki/OSSN/OSSN-0028
Reported-by: Daniel P. Berrangé <berrange@redhat.com>
Fix-suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-Id: <20190218181349.23885-1-ppandit@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The base ICP class knows how to interact with KVM. Adapt sPAPR to use it
instead of the ICP KVM class.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155023080638.1011724.792095453419098948.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
All this code is used with both the XICS and XIVE interrupt controllers.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
When compiling the ppc code with clang and -std=gnu99, there are a
couple of warnings/errors like this one:
CC ppc64-softmmu/hw/intc/xics.o
In file included from hw/intc/xics.c:35:
include/hw/ppc/xics.h:43:25: error: redefinition of typedef 'ICPState' is a C11 feature
[-Werror,-Wtypedef-redefinition]
typedef struct ICPState ICPState;
^
target/ppc/cpu.h:1181:25: note: previous definition is here
typedef struct ICPState ICPState;
^
Work around the problems by including the proper headers in spapr.h
and by using struct forward declarations in cpu.h.
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
The qemu_irq array is now allocated at the machine level using a sPAPR
IRQ set_irq handler depending on the chosen interrupt mode. The use of
this handler is slightly inefficient today but it will become necessary
when the 'dual' interrupt mode is introduced.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
SLOF receives a device tree and updates it with various properties
before switching to the guest kernel and QEMU is not aware of any changes
made by SLOF. Since there is no real RTAS (QEMU implements it), it makes
sense to pass the SLOF final device tree to QEMU to let it implement
RTAS related tasks better, such as PCI host bus adapter hotplug.
Specifially, now QEMU can find out the actual XICS phandle (for PHB
hotplug) and the RTAS linux,rtas-entry/base properties (for firmware
assisted NMI - FWNMI).
This stores the initial DT blob in the sPAPR machine and replaces it
in the KVMPPC_H_UPDATE_DT (new private hypercall) handler.
This adds an @update_dt_enabled machine property to allow backward
migration.
SLOF already has a hypercall since
https://github.com/aik/SLOF/commit/e6fc84652c9c0073f9183
This makes use of the new fdt_check_full() helper. In order to allow
the configure script to pick the correct DTC version, this adjusts
the DTC presense test.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
H_HOME_NODE_ASSOCIATIVITY H-Call returns the associativity domain
designation associated with the identifier input parameter
This fixes a crash when we try to hotplug a CPU in memory-less and
CPU-less numa node. In this case, the kernel tries to online the
node, but without the information provided by this h-call, the node id,
it cannot and the CPU is started while the node is not onlined.
It also removes the warning message from the kernel:
VPHN is not supported. Disabling polling..
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This option is used to select the interrupt controller mode (XICS or
XIVE) with which the machine will operate. XICS being the default
mode for now.
When running a machine with the XIVE interrupt mode backend, the guest
OS is required to have support for the XIVE exploitation mode. In the
case of legacy OS, the mode selected by CAS should be XICS and the OS
should fail to boot. However, QEMU could possibly detect it, terminate
the boot process and reset to stop in the SLOF firmware. This is not
yet handled.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The interrupt modes supported by the hypervisor are advertised to the
guest with new bits definitions of the option vector 5 of property
"ibm,arch-vec-5-platform-support. The byte 23 bits 0-1 of the OV5 are
defined as follow :
0b00 PAPR 2.7 and earlier (Legacy systems)
0b01 XIVE Exploitation mode only
0b10 Either available
If the client/guest selects the XIVE interrupt mode, it informs the
hypervisor by returning the value 0b01 in byte 23 bits 0-1. A 0b00
value indicates the use of the XICS interrupt mode (Legacy systems).
The sPAPR IRQ backend is extended with these definitions and the
values are directly used to populate the "ibm,arch-vec-5-platform-support"
property. The interrupt mode is advertised under TCG and under KVM.
Although a KVM XIVE device is not yet available, the machine can still
operate with kernel_irqchip=off. However, we apply a restriction on
the CPU which is required to be a POWER9 when a XIVE interrupt
controller is in use.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The different XIVE virtualization structures (sources and event queues)
are configured with a set of Hypervisor calls :
- H_INT_GET_SOURCE_INFO
used to obtain the address of the MMIO page of the Event State
Buffer (ESB) entry associated with the source.
- H_INT_SET_SOURCE_CONFIG
assigns a source to a "target".
- H_INT_GET_SOURCE_CONFIG
determines which "target" and "priority" is assigned to a source
- H_INT_GET_QUEUE_INFO
returns the address of the notification management page associated
with the specified "target" and "priority".
- H_INT_SET_QUEUE_CONFIG
sets or resets the event queue for a given "target" and "priority".
It is also used to set the notification configuration associated
with the queue, only unconditional notification is supported for
the moment. Reset is performed with a queue size of 0 and queueing
is disabled in that case.
- H_INT_GET_QUEUE_CONFIG
returns the queue settings for a given "target" and "priority".
- H_INT_RESET
resets all of the guest's internal interrupt structures to their
initial state, losing all configuration set via the hcalls
H_INT_SET_SOURCE_CONFIG and H_INT_SET_QUEUE_CONFIG.
- H_INT_SYNC
issue a synchronisation on a source to make sure all notifications
have reached their queue.
Calls that still need to be addressed :
H_INT_SET_OS_REPORTING_LINE
H_INT_GET_OS_REPORTING_LINE
See the code for more documentation on each hcall.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
[dwg: Folded in fix for field accessors]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The XIVE IRQ backend uses the same layout as the new XICS backend but
covers the full range of the IRQ number space. The IRQ numbers for the
CPU IPIs are allocated at the bottom of this space, below 4K, to
preserve compatibility with XICS which does not use that range.
This should be enough given that the maximum number of CPUs is 1024
for the sPAPR machine under QEMU. For the record, the biggest POWER8
or POWER9 system has a maximum of 1536 HW threads (16 sockets, 192
cores, SMT8).
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The XIVE sPAPR IRQ backend will use it to define the number of ENDs of
the IC controller.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Add the spapr cap SPAPR_CAP_NESTED_KVM_HV to be used to control the
availability of nested kvm-hv to the level 1 (L1) guest.
Assuming a hypervisor with support enabled an L1 guest can be allowed to
use the kvm-hv module (and thus run it's own kvm-hv guests) by setting:
-machine pseries,cap-nested-hv=true
or disabled with:
-machine pseries,cap-nested-hv=false
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The spapr-rng device is suboptimal when compared to virtio-rng, so
users might want to disable it in their builds. Thus let's introduce
a proper CONFIG switch to allow us to compile QEMU without this device.
The function spapr_rng_populate_dt is required for linking, so move it
to a different location.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This proposal moves all the related IRQ routines of the sPAPR machine
behind a sPAPR IRQ backend interface 'spapr_irq' to prepare for future
changes. First of which will be to increase the size of the IRQ number
space, then, will follow a new backend for the POWER9 XIVE IRQ controller.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This proposal introduces a new IRQ number space layout using static
numbers for all devices, depending on a device index, and a bitmap
allocator for the MSI IRQ numbers which are negotiated by the guest at
runtime.
As the VIO device model does not have a device index but a "reg"
property, we introduce a formula to compute an IRQ number from a "reg"
value. It should minimize most of the collisions.
The previous layout is kept in pre-3.1 machines raising the
'legacy_irq_allocation' machine class flag.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
It eases code review, unit is explicit.
Patch generated using:
$ git grep -E '(1024|2048|4096|8192|(<<|>>).?(10|20|30))' hw/ include/hw/
and modified manually.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20180625124238.25339-33-f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The way we used to handle KVM allowable guest pagesizes for PAPR guests
required some convoluted checking of memory attached to the guest.
The allowable pagesizes advertised to the guest cpus depended on the memory
which was attached at boot, but then we needed to ensure that any memory
later hotplugged didn't change which pagesizes were allowed.
Now that we have an explicit machine option to control the allowable
maximum pagesize we can simplify this. We just check all memory backends
against that declared pagesize. We check base and cold-plugged memory at
reset time, and hotplugged memory at pre_plug() time.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
The way the POWER Hash Page Table (HPT) MMU is virtualized by KVM HV means
that every page that the guest puts in the pagetables must be truly
physically contiguous, not just GPA-contiguous. In effect this means that
an HPT guest can't use any pagesizes greater than the host page size used
to back its memory.
At present we handle this by changing what we advertise to the guest based
on the backing pagesizes. This is pretty bad, because it means the guest
sees a different environment depending on what should be host configuration
details.
As a start on fixing this, we add a new capability parameter to the
pseries machine type which gives the maximum allowed pagesizes for an
HPT guest. For now we just create and validate the parameter without
making it do anything.
For backwards compatibility, on older machine types we set it to the max
available page size for the host. For the 3.0 machine type, we fix it to
16, the intention being to only allow HPT pagesizes up to 64kiB by default
in future.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
spapr_irq_alloc_block and spapr_irq_alloc() are now deprecated.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Today, when a device requests for IRQ number in a sPAPR machine, the
spapr_irq_alloc() routine first scans the ICSState status array to
find an empty slot and then performs the assignement of the selected
numbers. Split this sequence in two distinct routines : spapr_irq_find()
for lookups and spapr_irq_claim() for claiming the IRQ numbers.
This will ease the introduction of a static layout of IRQ numbers.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
spapr capabilities have an apply hook to actually activate (or deactivate)
the feature in the system at reset time. However, a number of capabilities
affect the setup of cpus, and need to be applied to each of them -
including hotplugged cpus for extra complication. To make this simpler,
add an optional cpu_apply hook that is called from spapr_cpu_reset().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Previously, the effective values of the various spapr capability flags
were only determined at machine reset time. That was a lazy way of making
sure it was after cpu initialization so it could use the cpu object to
inform the defaults.
But we've now improved the compat checking code so that we don't need to
instantiate the cpus to use it. That lets us move the resolution of the
capability defaults much earlier.
This is going to be necessary for some future capabilities.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Let's make it clear at relevant places that we are dealing with device
memory. That it can be used for memory hotplug is just a special case.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180423165126.15441-11-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
[ehabkost: rebased series, solved conflicts at spapr.c]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Let's allow to query the MemoryHotplugState directly from the machine.
If the pointer is NULL, the machine does not support memory devices. If
the pointer is !NULL, the machine supports memory devices and the
data structure contains information about the applicable physical
guest address space region.
This allows us to generically detect if a certain machine has support
for memory devices, and to generically manage it (find free address
range, plug/unplug a memory region).
We will rename "MemoryHotplugState" to something more meaningful
("DeviceMemory") after we completed factoring out the pc-dimm code into
MemoryDevice code.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180423165126.15441-3-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
[ehabkost: rebased series, solved conflicts at spapr.c]
[ehabkost: squashed fix to use g_malloc0()]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Convert cap-ibs (indirect branch speculation) to a custom spapr-cap
type.
All tristate caps have now been converted to custom spapr-caps, so
remove the remaining support for them.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
[dwg: Don't explicitly list "?"/help option, trust convention]
[dwg: Fold tristate removal into here, to not break bisect]
[dwg: Fix minor style problems]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The spapr_vcpu_id() function is an accessor actually. Let's rename it
for symmetry with the recently added spapr_set_vcpu_id() helper.
The motivation behind this is that a later patch will consolidate
the VCPU id formula in a function and spapr_vcpu_id looks like an
appropriate name.
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The VCPU ids are currently computed and assigned to each individual
CPU threads in spapr_cpu_core_realize(). But the numbering logic
of VCPU ids is actually a machine-level concept, and many places
in hw/ppc/spapr.c also have to compute VCPU ids out of CPU indexes.
The current formula used in spapr_cpu_core_realize() is:
vcpu_id = (cc->core_id * spapr->vsmt / smp_threads) + i
where:
cc->core_id is a multiple of smp_threads
cpu_index = cc->core_id + i
0 <= i < smp_threads
So we have:
cpu_index % smp_threads == i
cc->core_id / smp_threads == cpu_index / smp_threads
hence:
vcpu_id =
(cpu_index / smp_threads) * spapr->vsmt + cpu_index % smp_threads;
This formula was used before VSMT at the time VCPU ids where computed
at the target emulation level. It has the advantage of being useable
to derive a VPCU id out of a CPU index only. It is fitted for all the
places where the machine code has to compute a VCPU id.
This patch introduces an accessor to set the VCPU id in a PowerPCCPU object
using the above formula. It is a first step to consolidate all the VCPU id
logic in a single place.
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The new H-Call H_GET_CPU_CHARACTERISTICS is used by the guest to query
behaviours and available characteristics of the cpu.
Implement the handler for this new H-Call which formulates its response
based on the setting of the spapr_caps cap-cfpc, cap-sbbc and cap-ibs.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Add new tristate cap cap-ibs to represent the indirect branch
serialisation capability.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Add new tristate cap cap-sbbc to represent the speculation barrier
bounds checking capability.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Add new tristate cap cap-cfpc to represent the cache flush on privilege
change capability.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
spapr_caps are used to represent the level of support for various
capabilities related to the spapr machine type. Currently there is
only support for boolean capabilities.
Add support for tristate capabilities by implementing their get/set
functions. These capabilities can have the values 0, 1 or 2
corresponding to broken, workaround and fixed.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Add three new kvm capabilities used to represent the level of host support
for three corresponding workarounds.
Host support for each of the capabilities is queried through the
new ioctl KVM_PPC_GET_CPU_CHAR which returns four uint64 quantities. The
first two, character and behaviour, represent the available
characteristics of the cpu and the behaviour of the cpu respectively.
The second two, c_mask and b_mask, represent the mask of known bits for
the character and beheviour dwords respectively.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
[dwg: Correct some compile errors due to name change in final kernel
patch version]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Currently spapr_caps are tied to boolean values (on or off). This patch
reworks the caps so that they can have any uint8 value. This allows more
capabilities with various values to be represented in the same way
internally. Capabilities are numbered in ascending order. The internal
representation of capability values is an array of uint8s in the
sPAPRMachineState, indexed by capability number.
Capabilities can have their own name, description, options, getter and
setter functions, type and allow functions. They also each have their own
section in the migration stream. Capabilities are only migrated if they
were explictly set on the command line, with the assumption that
otherwise the default will match.
On migration we ensure that the capability value on the destination
is greater than or equal to the capability value from the source. So
long at this remains the case then the migration is considered
compatible and allowed to continue.
This patch implements generic getter and setter functions for boolean
capabilities. It also converts the existings cap-htm, cap-vsx and
cap-dfp capabilities to this new format.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Decimal Floating Point has been available on POWER7 and later (server)
cpus. However, it can be disabled on the hypervisor, meaning that it's
not available to guests.
We currently handle this by conditionally advertising DFP support in the
device tree depending on whether the guest CPU model supports it - which
can also depend on what's allowed in the host for -cpu host. That can lead
to confusion on migration, since host properties are silently affecting
guest visible properties.
This patch handles it by treating it as an optional capability for the
pseries machine type.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
We currently have some conditionals in the spapr device tree code to decide
whether or not to advertise the availability of the VMX (aka Altivec) and
VSX vector extensions to the guest, based on whether the guest cpu has
those features.
This can lead to confusion and subtle failures on migration, since it makes
a guest visible change based only on host capabilities. We now have a
better mechanism for this, in spapr capabilities flags, which explicitly
depend on user options rather than host capabilities.
Rework the advertisement of VSX and VMX based on a new VSX capability. We
no longer bother with a conditional for VMX support, because every CPU
that's ever been supported by the pseries machine type supports VMX.
NOTE: Some userspace distributions (e.g. RHEL7.4) already rely on
availability of VSX in libc, so using cap-vsx=off may lead to a fatal
SIGILL in init.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Now that the "pseries" machine type implements optional capabilities (well,
one so far) there's the possibility of having different capabilities
available at either end of a migration. Although arguably a user error,
it would be nice to catch this situation and fail as gracefully as we can.
This adds code to migrate the capabilities flags. These aren't pulled
directly into the destination's configuration since what the user has
specified on the destination command line should take precedence. However,
they are checked against the destination capabilities.
If the source was using a capability which is absent on the destination,
we fail the migration, since that could easily cause a guest crash or other
bad behaviour. If the source lacked a capability which is present on the
destination we warn, but allow the migration to proceed.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
This adds an spapr capability bit for Hardware Transactional Memory. It is
enabled by default for pseries-2.11 and earlier machine types. with POWER8
or later CPUs (as it must be, since earlier qemu versions would implicitly
allow it). However it is disabled by default for the latest pseries-2.12
machine type.
This means that with the latest machine type, HTM will not be available,
regardless of CPU, unless it is explicitly enabled on the command line.
That change is made on the basis that:
* This way running with -M pseries,accel=tcg will start with whatever cpu
and will provide the same guest visible model as with accel=kvm.
- More specifically, this means existing make check tests don't have
to be modified to use cap-htm=off in order to run with TCG
* We hope to add a new "HTM without suspend" feature in the not too
distant future which could work on both POWER8 and POWER9 cpus, and
could be enabled by default.
* Best guesses suggest that future POWER cpus may well only support the
HTM-without-suspend model, not the (frankly, horribly overcomplicated)
POWER8 style HTM with suspend.
* Anecdotal evidence suggests problems with HTM being enabled when it
wasn't wanted are more common than being missing when it was.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Because PAPR is a paravirtual environment access to certain CPU (or other)
facilities can be blocked by the hypervisor. PAPR provides ways to
advertise in the device tree whether or not those features are available to
the guest.
In some places we automatically determine whether to make a feature
available based on whether our host can support it, in most cases this is
based on limitations in the available KVM implementation.
Although we correctly advertise this to the guest, it means that host
factors might make changes to the guest visible environment which is bad:
as well as generaly reducing reproducibility, it means that a migration
between different host environments can easily go bad.
We've mostly gotten away with it because the environments considered mature
enough to be well supported (basically, KVM on POWER8) have had consistent
feature availability. But, it's still not right and some limitations on
POWER9 is going to make it more of an issue in future.
This introduces an infrastructure for defining "sPAPR capabilities". These
are set by default based on the machine version, masked by the capabilities
of the chosen cpu, but can be overriden with machine properties.
The intention is at reset time we verify that the requested capabilities
can be supported on the host (considering TCG, KVM and/or host cpu
limitations). If not we simply fail, rather than silently modifying the
advertised featureset to the guest.
This does mean that certain configurations that "worked" may now fail, but
such configurations were already more subtly broken.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
LoPAPR 1.1 B.6.9.1.2 describes the "#interrupt-cells" property of the
PowerPC External Interrupt Source Controller node as follows:
“#interrupt-cells”
Standard property name to define the number of cells in an interrupt-
specifier within an interrupt domain.
prop-encoded-array: An integer, encoded as with encode-int, that denotes
the number of cells required to represent an interrupt specifier in its
child nodes.
The value of this property for the PowerPC External Interrupt option shall
be 2. Thus all interrupt specifiers (as used in the standard “interrupts”
property) shall consist of two cells, each containing an integer encoded
as with encode-int. The first integer represents the interrupt number the
second integer is the trigger code: 0 for edge triggered, 1 for level
triggered.
This patch fixes the interrupt specifiers in the "interrupt-map" property
of the PHB node, that were setting the second cell to 8 (confusion with
IRQ_TYPE_LEVEL_LOW ?) instead of 1.
VIO devices and RTAS event sources use the same format for interrupt
specifiers: while here, we introduce a common helper to handle the
encoding details.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
--
v3: - reference public LoPAPR instead of internal PAPR+ in changelog
- change helper name to spapr_dt_xics_irq()
v2: - drop the erroneous changes to the "interrupts" prop in PCI device nodes
- introduce a common helper to encode interrupt specifiers
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
