Let's suggest to the user how the machine should be configured to allow
the guest to boot successfully.
Suggested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155799221739.527449.14907564571096243745.stgit@bahia.lan>
Reviewed-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Tested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
[dwg: Adjusted for style error]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
If a machine is started with ic-mode=xive but the guest only knows
about XICS, eg. an RHEL 7.6 guest, the kernel panics. This is
expected but a bit unfortunate since the crash doesn't provide
much information for the end user to guess what's happening.
Detect that during CAS and exit QEMU with a proper error message
instead, like it is already done for the MMU.
Even if this is less likely to happen, the opposite case of a guest
that only knows about XIVE would certainly fail all the same if the
machine is started with ic-mode=xics.
Also, the only valid values a guest can pass in byte 23 of OV5 during
CAS are 0b00 (XIVE legacy mode) and 0b01 (XIVE exploitation mode). Any
other value is a bug, at least with the current spec. Again, it does
not seem right to let the guest go on without a precise idea of the
interrupt mode it asked for.
Handle these cases as well.
Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <155793986451.464434.12887933000007255549.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
With MT-TCG, we are now running translation in a racy way, thus
we need to mimic hardware when it comes to updating the R and
C bits, by doing byte stores.
The current "store_hpte" abstraction is ill suited for this, we
replace it with two separate callbacks for setting R and C.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190411080004.8690-4-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190411080004.8690-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
176dccee "target/ppc/spapr: Clear partition table entry when allocating
hash table" reworked the H_REGISTER_PROCESS_TABLE hypercall, but
unfortunately due to a small error no longer correctly sets the LPCR[GTSE]
bit which allows the guest to directly execute (some types of) tlbie (TLB
flush) instructions without involving the hypervisor.
We got away with this, initially, because POWER9 did not have hypervisor
mode enabled in its msr_mask, which meant we didn't actually run hypervisor
privilege checks in TCG at all. However, da874d90 "target/ppc: add HV
support for POWER9" turned on HV support on POWER9 for the benefit of the
powernv machine type.
This exposed the earlier bug in H_REGISTER_PROCESS_TABLE, and causes guests
which rely on LPCR[GTSE] (i.e. basically all of them) to crash during early
boot when their first tlbie instruction causes an unexpected trap.
Fixes: 176dccee target/ppc/spapr: Clear partition table entry when allocating hash table
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>
Tested-by: Cleber Rosa <crosa@redhat.com>
The qemu coding standard is to use CamelCase for type and structure names,
and the pseries code follows that... sort of. There are quite a lot of
places where we bend the rules in order to preserve the capitalization of
internal acronyms like "PHB", "TCE", "DIMM" and most commonly "sPAPR".
That was a bad idea - it frequently leads to names ending up with hard to
read clusters of capital letters, and means they don't catch the eye as
type identifiers, which is kind of the point of the CamelCase convention in
the first place.
In short, keeping type identifiers look like CamelCase is more important
than preserving standard capitalization of internal "words". So, this
patch renames a heap of spapr internal type names to a more standard
CamelCase.
In addition to case changes, we also make some other identifier renames:
VIOsPAPR* -> SpaprVio*
The reverse word ordering was only ever used to mitigate the capital
cluster, so revert to the natural ordering.
VIOsPAPRVTYDevice -> SpaprVioVty
VIOsPAPRVLANDevice -> SpaprVioVlan
Brevity, since the "Device" didn't add useful information
sPAPRDRConnector -> SpaprDrc
sPAPRDRConnectorClass -> SpaprDrcClass
Brevity, and makes it clearer this is the same thing as a "DRC"
mentioned in many other places in the code
This is 100% a mechanical search-and-replace patch. It will, however,
conflict with essentially any and all outstanding patches touching the
spapr code.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
If we allocate a hash page table then we know that the guest won't be
using process tables, so set the partition table entry maintained for
the guest to zero. If this isn't done, then the guest radix bit will
remain set in the entry. This means that when the guest calls
H_REGISTER_PROCESS_TABLE there will be a mismatch between then flags
and the value in spapr->patb_entry, and the call will fail. The guest
will then panic:
Failed to register process table (rc=-4)
kernel BUG at arch/powerpc/platforms/pseries/lpar.c:959
The result being that it isn't possible to boot a hash guest on a P9
system.
Also fix a bug in the flags parsing in h_register_process_table() which
was introduced by the same patch, and simplify the handling to make it
less likely that errors will be introduced in the future. The effect
would have been setting the host radix bit LPCR_HR for a hash guest
using process tables, which currently isn't supported and so couldn't
have been triggered.
Fixes: 00fd075e18 "target/ppc/spapr: Set LPCR:HR when using Radix mode"
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Message-Id: <20190305022102.17610-1-sjitindarsingh@gmail.com>
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>
That "b" means "base address" and thus shouldn't be in the name
of actual entries and related constants.
This patch keeps the synthetic patb_entry field of the spapr
virtual hypervisor unchanged until I figure out if that has
an impact on the migration stream.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190215170029.15641-11-clg@kaod.org>
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>
The 'dual' sPAPR IRQ backend supports both interrupt mode, XIVE
exploitation mode and the legacy compatibility mode (XICS). both modes
are not supported at the same time.
The machine starts with the legacy mode and a new interrupt mode can
then be negotiated by the CAS process. In this case, the new mode is
activated after a reset to take into account the required changes in
the machine. These impact the device tree layout, the interrupt
presenter object and the exposed MMIO regions in the case of XIVE.
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>
CPUPPCState currently contains a number of fields containing the state of
the VPA. The VPA is a PAPR specific concept covering several guest/host
shared memory areas used to communicate some information with the
hypervisor.
As a PAPR concept this is really machine specific information, although it
is per-cpu, so it doesn't really belong in the core CPU state structure.
There's also other information that's per-cpu, but platform/machine
specific. So create a (void *)machine_data in PowerPCCPU which can be
used by the machine to locate per-cpu data. Intialization, lifetime and
cleanup of machine_data is entirely up to the machine type.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
If the negotiated compat mode can't be set, but raw mode is supported,
we decide to ignore the error. An so, we should free it to prevent a
memory leak.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Rename it to better match the new terminology.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180423165126.15441-9-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
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>
On the qmp level, we already have the concept of memory devices:
"query-memory-devices"
Right now, we only support NVDIMM and PCDIMM.
We want to map other devices later into the address space of the guest.
Such device could e.g. be virtio devices. These devices will have a
guest memory range assigned but won't be exposed via e.g. ACPI. We want
to make them look like memory device, but not glued to pc-dimm.
Especially, it will not always be possible to have TYPE_PC_DIMM as a parent
class (e.g. virtio devices). Let's use an interface instead. As a first
part, convert handling of
- qmp_pc_dimm_device_list
- get_plugged_memory_size
to our new model. plug/unplug stuff etc. will follow later.
A memory device will have to provide the following functions:
- get_addr(): Necessary, as the property "addr" can e.g. not be used for
virtio devices (already defined).
- get_plugged_size(): The amount this device offers to the guest as of
now.
- get_region_size(): Because this can later on be bigger than the
plugged size.
- fill_device_info(): Fill MemoryDeviceInfo, e.g. for qmp.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180423165126.15441-2-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
There are several places in spapr_hcall.c where we need to update the LPCR
value on all CPUs. We do this with the set_spr() helper. That's not
really correct because this directly sets the SPR value, without going
through the ppc_store_lpcr() helper which may need to update state based
on the LPCR change.
In fact, set_spr() is only ever used for the LPCR, so replace it with an
explicit LPCR updated which uses the right low-level helper. While we're
there, move the CPU_FOREACH() which was in every one of the callers into
the new helper: set_all_lpcrs().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
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>
Newer kernels have a htab resize capability when adding or remove
memory. At these situations, the guest kernel might reallocate its
htab to a more suitable size based on the resulting memory.
However, we're not setting the new value back into the machine state
when a KVM guest resizes its htab. At first this doesn't seem harmful,
but when migrating or saving the guest state (via virsh managedsave,
for instance) this mismatch between the htab size of QEMU and the
kernel makes the guest hangs when trying to load its state.
Inside h_resize_hpt_commit, the hypercall that commits the hash page
resize changes, let's set spapr->htab_shift to the new value if we're
sure that kvmppc_resize_hpt_commit were successful.
While we're here, add a "not RADIX" sanity check as it is already done
in the related hypercall h_resize_hpt_prepare.
Fixes: https://github.com/open-power-host-os/qemu/issues/28
Reported-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Commit bcb5ce08cf ("spapr: Rename machine init functions for clarity")
renamed ppc_spapr_reset to spapr_machine_reset and ppc_spapr_init
to spapr_machine_init. Let's also rename the references in
comments.
Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Detected by Coverity (CID 1385702). This fixes the recently added hypercall
to let guests properly apply Spectre and Meltdown workarounds.
Fixes: c59704b254 "target/ppc/spapr: Add H-Call H_GET_CPU_CHARACTERISTICS"
Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
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>
applied using ./scripts/clean-includes
not needed since 7ebaf79556
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
KVM HV will soon support running a guest in hash mode on a POWER9 host
running in radix mode (see [1]), however the guest currently fails to
boot.
This is because the "htab_shift" value (the size of the MMU's hash
table) is added to the device tree before KVM has had a chance to
change it. If the host is in hash mode, KVM does not need to change it
and so the problem is not seen, but when the host is in radix mode a
change is required and we see a problem.
To fix this, move the call spapr_setup_hpt_and_vrma() (where
htab_shift could be changed) up a little so that it's called before
spapr_h_cas_compose_response() (where htab_shift is added to the
device tree).
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
[1] See http://www.spinics.net/lists/kvm-ppc/msg13057.html
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
In order to prevent the guest from forcing the allocation of large amounts
of qemu memory (or host kernel memory, in the case of KVM HV), we limit
the size of Hashed Page Table (HPT) it is allowed to allocated, based on
its RAM size.
However, the current calculation is not correct: it only adds up the size
of plugged memory, ignoring the base memory size. This patch corrects it.
While we're there, use get_plugged_memory_size() instead of directly
calling pc_existing_dimms_capacity(). The only difference is that it
will abort on failure, which is right: a failure here indicates something
wrong within qemu.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
When running with KVM PR, if a new HPT is allocated we need to inform
KVM about the HPT address and size. This is currently done by hacking
the value of SDR1 and pushing it to KVM in several places.
Also, migration breaks the guest since it is very unlikely the HPT has
the same address in source and destination, but we push the incoming
value of SDR1 to KVM anyway.
This patch introduces a new virtual hypervisor hook so that the spapr
code can provide the correct value of SDR1 to be pushed to KVM each
time kvmppc_put_books_sregs() is called.
It allows to get rid of all the hacking in the spapr/kvmppc code and
it fixes migration of nested KVM PR.
Suggested-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>
The OV5_MMU_RADIX_300 requires special handling in the CAS negotiation
process. It is cleared from the option vector of the guest before
evaluating the changes and re-added later. But, when testing for a
possible CAS reset :
spapr->cas_reboot = spapr_ovec_diff(ov5_updates,
ov5_cas_old, spapr->ov5_cas);
the bit OV5_MMU_RADIX_300 will each time be seen as removed from the
previous OV5 set, hence generating a reset loop.
Fix this problem by also clearing the same bit in the ov5_cas_old set.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Commit b55d295e3e added the possibility to support HPT resizing with KVM.
In the case of PR, we need to pass the userspace address of the HPT to KVM
using the SDR1 slot.
This is handled by kvmppc_update_sdr1() which uses CPU_FOREACH() to update
all CPUs. It is hence not needed to call kvmppc_update_sdr1() for each CPU.
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
KVM PR doesn't allow to set a compat mode. This causes ppc_set_compat_all()
to fail and we return H_HARDWARE to the guest right away.
This is excessive: even if we favor compat mode since commit 152ef803ce,
we should at least fallback to raw mode if the guest supports it.
This patch modifies cas_check_pvr() so that it also reports that the real
PVR was found in the table supplied by the guest. Note that this is only
makes sense if raw mode isn't explicitely disabled (ie, the user didn't
set the machine "max-cpu-compat" property). If this is the case, we can
simply ignore ppc_set_compat_all() failures, and let the guest run in raw
mode.
Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The concept of a VCPU ID that differs from the CPU's index
(cpu->cpu_index) exists only within SPAPR machines so, move the
functions ppc_get_vcpu_id() and ppc_get_cpu_by_vcpu_id() into spapr.c
and rename them appropriately.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This field actually records the VCPU ID used by KVM and, although the
value is also used in the device tree it is primarily the VCPU ID so
rename it as such.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
[dwg: Updated comment missed in cpu.h]
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The unicast case in h_signal_sys_reset() seems to be broken:
rather than selecting the target CPU, it looks like it will pick
either the first CPU or fail to find one at all.
Fix it by using the search function rather than open coding the
search.
This was found by inspection; the code appears to be unused because
the Linux kernel only uses the broadcast target.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
So far, qemu implements the PAPR Hash Page Table (HPT) resizing extension
with TCG. The same implementation will work with KVM PR, but we don't
currently allow that. For KVM HV we can only implement resizing with the
assistance of the host kernel, which needs a new capability and ioctl()s.
This patch adds support for testing the new KVM capability and implementing
the resize in terms of KVM facilities when necessary. If we're running on
a kernel which doesn't have the new capability flag at all, we fall back to
testing for PR vs. HV KVM using the same hack that we already use in a
number of places for older kernels.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
We've now implemented a PAPR extension allowing PAPR guest to resize
their hash page table (HPT) during runtime.
This patch makes use of that facility to allocate smaller HPTs by default.
Specifically when a guest is aware of the HPT resize facility, qemu sizes
the HPT to the initial memory size, rather than the maximum memory size on
the assumption that the guest will resize its HPT if necessary for hot
plugged memory.
When the initial memory size is much smaller than the maximum memory size
(a common configuration with e.g. oVirt / RHEV) then this can save
significant memory on the HPT.
If the guest does *not* advertise HPT resize awareness when it makes the
ibm,client-architecture-support call, qemu resizes the HPT for maxmimum
memory size (unless it's been configured not to allow such guests at all).
For now we make that reallocation assuming the guest has not yet used the
HPT at all. That's true in practice, but not, strictly, an architectural
or PAPR requirement. If we need to in future we can fix this by having
the client-architecture-support call reboot the guest with the revised
HPT size (the client-architecture-support call is explicitly permitted to
trigger a reboot in this way).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
This patch implements hypercalls allowing a PAPR guest to resize its own
hash page table. This will eventually allow for more flexible memory
hotplug.
The implementation is partially asynchronous, handled in a special thread
running the hpt_prepare_thread() function. The state of a pending resize
is stored in SPAPR_MACHINE->pending_hpt.
The H_RESIZE_HPT_PREPARE hypercall will kick off creation of a new HPT, or,
if one is already in progress, monitor it for completion. If there is an
existing HPT resize in progress that doesn't match the size specified in
the call, it will cancel it, replacing it with a new one matching the
given size.
The H_RESIZE_HPT_COMMIT completes transition to a resized HPT, and can only
be called successfully once H_RESIZE_HPT_PREPARE has successfully
completed initialization of a new HPT. The guest must ensure that there
are no concurrent accesses to the existing HPT while this is called (this
effectively means stop_machine() for Linux guests).
For now H_RESIZE_HPT_COMMIT goes through the whole old HPT, rehashing each
HPTE into the new HPT. This can have quite high latency, but it seems to
be of the order of typical migration downtime latencies for HPTs of size
up to ~2GiB (which would be used in a 256GiB guest).
In future we probably want to move more of the rehashing to the "prepare"
phase, by having H_ENTER and other hcalls update both current and
pending HPTs. That's a project for another day, but should be possible
without any changes to the guest interface.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This introduces stub implementations of the H_RESIZE_HPT_PREPARE and
H_RESIZE_HPT_COMMIT hypercalls which we hope to add in a PAPR
extension to allow run time resizing of a guest's hash page table. It
also adds a new machine property for controlling whether this new
facility is available.
For now we only allow resizing with TCG, allowing it with KVM will require
kernel changes as well.
Finally, it adds a new string to the hypertas property in the device
tree, advertising to the guest the availability of the HPT resizing
hypercalls. This is a tentative suggested value, and would need to be
standardized by PAPR before being merged.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Server class POWER CPUs have a "compat" property, which is used to set the
backwards compatibility mode for the processor. However, this only makes
sense for machine types which don't give the guest access to hypervisor
privilege - otherwise the compatibility level is under the guest's control.
To reflect this, this removes the CPU 'compat' property and instead
creates a 'max-cpu-compat' property on the pseries machine. Strictly
speaking this breaks compatibility, but AFAIK the 'compat' option was
never (directly) used with -device or device_add.
The option was used with -cpu. So, to maintain compatibility, this
patch adds a hack to the cpu option parsing to strip out any compat
options supplied with -cpu and set them on the machine property
instead of the now deprecated cpu property.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Tested-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
Tested-by: Andrea Bolognani <abologna@redhat.com>
set_spr is used in the function h_register_process_table() to update the
LPCR_GTSE and LPCR_UPRT values based on the flags passed by the guest.
The set_spr function takes the last two arguments mask and value used to
mask and set the value of the spr respectively.
The current call site passes these arguments in the wrong order and thus
bot GTSE and UPRT will be set irrespective, which is obviously
incorrect.
Rearrange the function call so that these arguments are passed in the
correct order and the correct behaviour is exhibited.
It is worth noting that this wasn't detected earlier since these were
always both set in all cases where this H_CALL was made.
Fixes: 6de833070c ("target/ppc: Set UPRT and GTSE on all cpus in H_REGISTER_PROCESS_TABLE")
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Assorted accumulated patches. These are nearly all bugfixes at one
level or another - some for longstanding problems, others for some
regressions caused by more recent cleanups.
This includes preliminary patches towards fixing migration for Radix
Page Table guests under POWER9 and also fixing some migration
regressions due to the re-organization of the interrupt controller
code. Not all the pieces are there yet, so those still won't quite
work, but the preliminary changes make sense on their own.
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Merge remote-tracking branch 'dgibson/tags/ppc-for-2.10-20170525' into staging
ppc patch queue 2017-05-25
Assorted accumulated patches. These are nearly all bugfixes at one
level or another - some for longstanding problems, others for some
regressions caused by more recent cleanups.
This includes preliminary patches towards fixing migration for Radix
Page Table guests under POWER9 and also fixing some migration
regressions due to the re-organization of the interrupt controller
code. Not all the pieces are there yet, so those still won't quite
work, but the preliminary changes make sense on their own.
# gpg: Signature made Thu 25 May 2017 04:50:00 AM BST
# gpg: using RSA key 0x6C38CACA20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>"
# gpg: aka "David Gibson (kernel.org) <dwg@kernel.org>"
# gpg: aka "David Gibson (Red Hat) <dgibson@redhat.com>"
# gpg: aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>"
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E 87DC 6C38 CACA 20D9 B392
* dgibson/tags/ppc-for-2.10-20170525:
xics: add unrealize handler
hw/ppc/spapr.c: recover pending LMB unplug info in spapr_lmb_release
hw/ppc: migrating the DRC state of hotplugged devices
hw/ppc: removing drc->detach_cb and drc->detach_cb_opaque
hw/ppc/spapr.c: adding pending_dimm_unplugs to sPAPRMachineState
spapr: add pre_plug function for memory
pseries: Restore support for total vcpus not a multiple of threads-per-core for old machine types
pseries: Split CAS PVR negotiation out into a separate function
spapr: fix error reporting in xics_system_init()
spapr_cpu_core: drop reference on ICP object during CPU realization
hw/ppc/spapr_events.c: removing 'exception' from sPAPREventLogEntry
spapr: ensure core_slot isn't NULL in spapr_core_unplug()
xics_kvm: cache already enabled vCPU ids
spapr: Consolidate HPT freeing code into a routine
spapr-cpu-core: release ICP object when realization fails
spapr: sanitize error handling in spapr_ics_create()
ppc/xics: simplify prototype of xics_spapr_init()
target/ppc: reset reservation in do_rfi()
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Guests of the qemu machine type go through a feature negotiation process
known as "client architecture support" (CAS) during early boot. This does
a number of things, one of which is finding a CPU compatibility mode which
can be supported by both guest and host.
In fact the CPU negotiation is probably the single most complex part of the
CAS process, so this splits it out into a helper function. We've recently
made some mistakes in maintaining backward compatibility for old machine
types here. Splitting this out will also make it easier to fix this.
This also adds a possibly useful error message if the negotiation fails
(i.e. if there isn't a CPU mode that's suitable for both guest and host).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Consolidate the code that frees HPT into a separate routine
spapr_free_hpt() as the same chunk of code is called from two places.
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Time to wire up all the call sites that request a shutdown or
reset to use the enum added in the previous patch.
It would have been less churn to keep the common case with no
arguments as meaning guest-triggered, and only modified the
host-triggered code paths, via a wrapper function, but then we'd
still have to audit that I didn't miss any host-triggered spots;
changing the signature forces us to double-check that I correctly
categorized all callers.
Since command line options can change whether a guest reset request
causes an actual reset vs. a shutdown, it's easy to also add the
information to reset requests.
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au> [ppc parts]
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> [SPARC part]
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> [s390x parts]
Message-Id: <20170515214114.15442-5-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
The UPRT and GTSE bits are set when a guest calls H_REGISTER_PROCESS_TABLE
to choose determine how address translation is performed. Currently these
bits in the LPCR are only set for the cpu which handles the H_CALL, however
they need to be set for all cpus for that guest as address translation
cannot be performed differently on a per cpu basis.
Update the H_CALL handler to set these bits in the LPCR correctly for all
cpus of the guest.
Note it is the reponsibility of the guest to ensure that any secondary cpus
are suspended when the H_CALL is made and thus we can safely update these
values here.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
For a little while around 4.9, Linux kernels that saw the radix bit in
ibm,pa-features would attempt to set up the MMU as if they were a
hypervisor, even if they were a guest, which would cause them to
crash.
Work around this by detecting pre-ISA 3.0 guests by their lack of that
bit in option vector 1, and then removing the radix bit from
ibm,pa-features. Note: This now requires regeneration of that node
after CAS negotiation.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
[dwg: Fix style nits]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Add the new node, /chosen/ibm,arch-vec-5-platform-support to the
device tree. This allows the guest to determine which modes are
supported by the hypervisor.
Update the option vector processing in h_client_architecture_support()
to handle the new MMU bits. This allows guests to request hash or
radix mode and QEMU to create the guest's HPT at this time if it is
necessary but hasn't yet been done. QEMU will terminate the guest if
it requests an unavailable mode, as required by the architecture.
Extend the ibm,pa-features node with the new ISA 3.0 values
and set the radix bit if KVM supports radix mode. This probably won't
be used directly by guests to determine the availability of radix mode
(that is indicated by the new node added above) but the architecture
requires that it be set when the hardware supports it.
If QEMU is using KVM, and KVM is capable of running in radix mode,
guests can be run in real-mode without allocating a HPT (because KVM
will use a minimal RPT). So in this case, we avoid creating the HPT
at reset time and later (during CAS) create it if it is necessary.
ISA 3.0 guests will now begin to call h_register_process_table(),
which has been added previously.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
[dwg: Strip some unneeded prefix from error messages]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The H_REGISTER_PROCESS_TABLE H_CALL is used by a guest to indicate to the
hypervisor where in memory its process table is and how translation should
be performed using this process table.
Provide the implementation of this H_CALL for a guest.
We first check for invalid flags, then parse the flags to determine the
operation, and then check the other parameters for valid values based on
the operation (register new table/deregister table/maintain registration).
The process table is then stored in the appropriate location and registered
with the hypervisor (if running under KVM), and the LPCR_[UPRT/GTSE] bits
are updated as required.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
[dwg: Correct missing prototype and uninitialized variable]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
