Commit graph

166 commits

Author SHA1 Message Date
Eduardo Habkost 4fb73f1d3b i386: kvm: extract CPUID entry lookup to cpuid_find_entry() function
No behavior change, just code movement.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-30 23:39:46 -02:00
Eduardo Habkost 829ae2f9fa i386: kvm: extract register switch to cpuid_entry_get_reg() function
No behavior change: just code movement.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-30 23:39:46 -02:00
Eduardo Habkost 47111e2cfa i386: kvm: kvm_arch_get_supported_cpuid: use 'entry' variable
The reg switch will be moved to a separate function, so store the entry
pointer in a variable.

No behavior change, just code movement.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-30 23:39:46 -02:00
Eduardo Habkost 8c723b7958 i386: kvm: kvm_arch_get_supported_cpuid: clean up has_kvm_features check
Instead of a function-specific has_kvm_features variable, simply use a
"found" variable that will be checked in case we have to use the legacy
get_para_features() interface.

No behavior change, just code cleanup.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-30 23:39:46 -02:00
Eduardo Habkost 7b46e5ce81 i386: kvm: kvm_arch_get_supported_cpuid: move R_EDX hack outside of for loop
The for loop will become a separate function, so clean it up so it can
become independent from the bit hacking for R_EDX.

No behavior change[1], just code movement.

[1] Well, only if the kernel returned CPUID leafs 1 or 0x80000001 as
    unsupported, but there's no kernel version that does that.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-10-30 23:39:45 -02:00
Avi Kivity a8170e5e97 Rename target_phys_addr_t to hwaddr
target_phys_addr_t is unwieldly, violates the C standard (_t suffixes are
reserved) and its purpose doesn't match the name (most target_phys_addr_t
addresses are not target specific).  Replace it with a finger-friendly,
standards conformant hwaddr.

Outstanding patchsets can be fixed up with the command

  git rebase -i --exec 'find -name "*.[ch]"
                        | xargs s/target_phys_addr_t/hwaddr/g' origin

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-10-23 08:58:25 -05:00
Eduardo Habkost 8fad4b44a0 i386: kvm: use a #define for the set of alias feature bits
Instea of using a hardcoded hex constant, define CPUID_EXT2_AMD_ALIASES
as the set of CPUID[8000_0001].EDX bits that on AMD are the same as the
bits of CPUID[1].EDX.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-By: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Don Slutz <Don@CloudSwitch.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-09-30 11:11:00 +00:00
Eduardo Habkost b1f4679392 i386: kvm: bit 10 of CPUID[8000_0001].EDX is reserved
Bit 10 of CPUID[8000_0001].EDX is not defined as an alias of
CPUID[1].EDX[10], so do not duplicate it on
kvm_arch_get_supported_cpuid().

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-By: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Don Slutz <Don@CloudSwitch.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-09-30 11:10:38 +00:00
Jan Kiszka b139bd300f kvm: i386: Add services required for PCI device assignment
These helpers abstract the interaction of upcoming pci-assign with the
KVM kernel services. Put them under i386 only as other archs will
implement device pass-through via VFIO and not this classic interface.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-09-10 15:29:59 +03:00
Michael S. Tsirkin bc9a839d56 kvm: get/set PV EOI MSR
Support get/set of new PV EOI MSR, for migration.
Add an optional section for MSR value - send it
out in case MSR was changed from the default value (0).

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-08-29 10:51:28 -05:00
Peter Maydell f3e1bed8da kvm: Decouple 'GSI routing' from 'kernel irqchip'
Don't assume having an in-kernel irqchip means that GSI
routing is enabled.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-09 16:16:57 +03:00
Peter Maydell 614e41bc26 kvm: Decouple 'MSI routing via irqfds' from 'kernel irqchip'
Decouple another x86-specific assumption about what irqchips imply.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-09 16:16:56 +03:00
Peter Maydell cc7e0ddf5a kvm: Decouple 'irqfds usable' from 'kernel irqchip'
Instead of assuming that we can use irqfds if and only if
kvm_irqchip_in_kernel(), add a bool to the KVMState which
indicates this, and is set only on x86 and only if the
irqchip is in the kernel.

The kernel documentation implies that the only thing
you need to use KVM_IRQFD is that KVM_CAP_IRQFD is
advertised, but this seems to be untrue. In particular
the kernel does not (alas) return a sensible error if you
try to set up an irqfd when you haven't created an irqchip.
If it did we could remove all this nonsense and let the
kernel return the error code.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-09 16:16:56 +03:00
Peter Maydell 1d31f66bbc kvm: Move kvm_allows_irq0_override() to target-i386, fix return type
kvm_allows_irq0_override() is a totally x86 specific concept:
move it to the target-specific source file where it belongs.
This means we need a new header file for the prototype:
kvm_i386.h, in line with the existing kvm_ppc.h.

While we are moving it, fix the return type to be 'bool' rather
than 'int'.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-09 16:16:55 +03:00
Igor Mammedov dd673288a8 target-i386: move cpu halted decision into x86_cpu_reset
MP initialization protocol differs between cpu families, and for P6 and
onward models it is up to CPU to decide if it will be BSP using this
protocol, so try to model this. However there is no point in implementing
MP initialization protocol in qemu. Thus first CPU is always marked as BSP.

This patch:
 - moves decision to designate BSP from board into cpu, making cpu
self-sufficient in this regard. Later it will allow to cleanup hw/pc.c
and remove cpu_reset and wrappers from there.
 - stores flag that CPU is BSP in IA32_APIC_BASE to model behavior
described in Inted SDM vol 3a part 1 chapter 8.4.1
 - uses MSR_IA32_APICBASE_BSP flag in apic_base for checking if cpu is BSP

patch is based on Jan Kiszka's proposal:
    http://thread.gmane.org/gmane.comp.emulators.qemu/100806

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-08-01 08:45:06 -05:00
Jan Kiszka 5d62c43a17 apic: Defer interrupt updates to VCPU thread
KVM performs TPR raising asynchronously to QEMU, specifically outside
QEMU's global lock. When an interrupt is injected into the APIC and TPR
is checked to decide if this can be delivered, a stale TPR value may be
used, causing spurious interrupts in the end.

Fix this by deferring apic_update_irq to the context of the target VCPU.
We introduce a new interrupt flag for this, CPU_INTERRUPT_POLL. When it
is set, the VCPU calls apic_poll_irq before checking for further pending
interrupts. To avoid special-casing KVM, we also implement this logic
for TCG mode.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-07-10 11:31:09 +03:00
Liu, Jinsong a75b3e0f64 kvm: expose tsc deadline timer feature to guest
This patch exposes tsc deadline timer feature to guest if
1). in-kernel irqchip is used, and
2). kvm has emulated tsc deadline timer, and
3). user authorize the feature exposing via -cpu or +/- tsc-deadline

Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-03 17:36:32 -03:00
Andreas Färber 232fc23bed target-i386: Pass X86CPU to do_cpu_{init,sipi}()
Allows to use cpu_reset() in place of cpu_state_reset().

Signed-off-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
2012-06-04 23:00:42 +02:00
Andreas Färber 317ac6201a target-i386: Don't overuse CPUState
Scripted conversion:
  sed -i "s/CPUState/CPUX86State/g" target-i386/*.[hc]
  sed -i "s/#define CPUX86State/#define CPUState/" target-i386/cpu.h

Signed-off-by: Andreas Färber <afaerber@suse.de>
Acked-by: Anthony Liguori <aliguori@us.ibm.com>
2012-03-14 22:20:25 +01:00
Michael S. Tsirkin 7e680753cf kvm: fill in padding to help valgrind
valgrind warns about padding fields which are passed
to vcpu ioctls uninitialized.
This is not an error in practice because kvm ignored padding.
Since the ioctls in question are off data path and
the cost is zero anyway, initialize padding to 0
to suppress these errors.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-07 12:31:48 +02:00
Jan Kiszka d362e757d3 target-i386: Add infrastructure for reporting TPR MMIO accesses
This will allow the APIC core to file a TPR access report. Depending on
the accelerator and kernel irqchip mode, it will either be delivered
right away or queued for later reporting.

In TCG mode, we can restart the triggering instruction and can therefore
forward the event directly. KVM does not allows us to restart, so we
postpone the delivery of events recording in the user space APIC until
the current instruction is completed.

Note that KVM without in-kernel irqchip will report the address after
the instruction that triggered the access.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-02-18 12:15:55 +02:00
Gleb Natapov d1f8663660 kvm: Synchronize cpu state in kvm_arch_stop_on_emulation_error()
Call to kvm_cpu_synchronize_state() is missing.
kvm_arch_stop_on_emulation_error may look at outdated registers here.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
2012-02-16 18:21:46 +02:00
Jan Kiszka 3d4b26494f kvm: Implement kvm_irqchip_in_kernel like kvm_enabled
To both avoid that kvm_irqchip_in_kernel always has to be paired with
kvm_enabled and that the former ends up in a function call, implement it
like the latter. This means keeping the state in a global variable and
defining kvm_irqchip_in_kernel as a preprocessor macro.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-02-08 15:57:50 -02:00
Jan Kiszka 39d6960aab kvm: Allow to set shadow MMU size
Introduce the KVM-specific machine option kvm_shadow_mem. It allows to
set a custom shadow MMU size for the virtual machine. This is useful for
stress testing e.g.

Only x86 supports this for now, but it is in principle a generic
concept for all targets with shadow MMUs.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-02-08 15:57:50 -02:00
Jan Kiszka 680c1c6fd7 kvm: x86: Add user space part for in-kernel APIC
This introduces the alternative APIC device which makes use of KVM's
in-kernel device model. External NMI injection via LINT1 is emulated by
checking the current state of the in-kernel APIC, only injecting a NMI
into the VCPU if LINT1 is unmasked and configured to DM_NMI.

MSI is not yet supported, so we disable this when the in-kernel model is
in use.

CC: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
2012-01-19 12:14:42 +01:00
Jan Kiszka 84b058d7df kvm: Introduce core services for in-kernel irqchip support
Add the basic infrastructure to active in-kernel irqchip support, inject
interrupts into these models, and maintain IRQ routes.

Routing is optional and depends on the host arch supporting
KVM_CAP_IRQ_ROUTING. When it's not available on x86, we looe the HPET as
we can't route GSI0 to IOAPIC pin 2.

In-kernel irqchip support will once be controlled by the machine
property 'kernel_irqchip', but this is not yet wired up.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
2012-01-19 12:14:42 +01:00
Vadim Rozenfeld eab70139a6 hyper-v: initialize Hyper-V CPUID leaves.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-01-19 08:33:12 -02:00
Anthony Liguori f3c6a169a3 Merge remote-tracking branch 'qemu-kvm/memory/page_desc' into staging
* qemu-kvm/memory/page_desc: (22 commits)
  Remove cpu_get_physical_page_desc()
  sparc: avoid cpu_get_physical_page_desc()
  virtio-balloon: avoid cpu_get_physical_page_desc()
  vhost: avoid cpu_get_physical_page_desc()
  kvm: avoid cpu_get_physical_page_desc()
  memory: remove CPUPhysMemoryClient
  xen: convert to MemoryListener API
  memory: temporarily add memory_region_get_ram_addr()
  xen, vga: add API for registering the framebuffer
  vhost: convert to MemoryListener API
  kvm: convert to MemoryListener API
  kvm: switch kvm slots to use host virtual address instead of ram_addr_t
  memory: add API for observing updates to the physical memory map
  memory: replace cpu_physical_sync_dirty_bitmap() with a memory API
  framebuffer: drop use of cpu_physical_sync_dirty_bitmap()
  loader: remove calls to cpu_get_physical_page_desc()
  framebuffer: drop use of cpu_get_physical_page_desc()
  memory: introduce memory_region_find()
  memory: add memory_region_is_logging()
  memory: add memory_region_is_rom()
  ...
2012-01-03 14:39:05 -06:00
Jan Kiszka cce47516cd kvm: x86: Drop redundant apic base and tpr update from kvm_get_sregs
The latter was already commented out, the former is redundant as well.
We always get the latest changes after return from the guest via
kvm_arch_post_run.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-22 14:53:01 -02:00
Jan Kiszka fabacc0f79 kvm: x86: Avoid runtime allocation of xsave buffer
Keep a per-VCPU xsave buffer for kvm_put/get_xsave instead of
continuously allocating and freeing it on state sync.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-22 14:53:01 -02:00
Jan Kiszka 6b42494b21 kvm: x86: Use symbols for all xsave field
Field 0 (FCW+FSW) and 1 (FTW+FOP) were hard-coded so far.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-22 14:53:00 -02:00
Avi Kivity 9f213ed92c kvm: switch kvm slots to use host virtual address instead of ram_addr_t
This simplifies a later switch to the memory API in slot management.

Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-20 14:14:07 +02:00
Vagrant Cascadian 126197214e Fix typo: runnning -> running
One n too many for running, need we say more.

Signed-Off-By: Vagrant Cascadian <vagrant@freegeek.org>

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-11-17 12:57:41 +00:00
Avi Kivity 21e87c4625 i386: wire up MSR_IA32_MISC_ENABLE
It's needed for its default value - bit 0 specifies that "rep movs" is
good enough for memcpy, and Linux may use a slower memcpu if it is not set,
depending on cpu family/model.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-10-24 21:33:32 -02:00
Liu, Jinsong aa82ba549a kvm: support TSC deadline MSR with subsection
KVM add emulation of lapic tsc deadline timer for guest.
This patch is co-operation work at qemu side.

Use subsections to save/restore the field (mtosatti).

Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-10-24 21:29:07 -02:00
Marcelo Tosatti 38d2c27ea6 Revert "kvm: support TSC deadline MSR"
This reverts commit bfc2455ddb.
New patch with subsections will follow.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-10-24 21:27:16 -02:00
Liu, Jinsong bfc2455ddb kvm: support TSC deadline MSR
KVM add emulation of lapic tsc deadline timer for guest.
This patch is co-operation work at qemu side.

Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-10-03 13:53:14 -03:00
Luiz Capitulino 1354869c38 Drop the vm_running global variable
Use runstate_is_running() instead, which is introduced by this commit.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2011-09-15 16:39:32 -03:00
Luiz Capitulino 1dfb4dd993 Replace the VMSTOP macros with a proper state type
Today, when notifying a VM state change with vm_state_notify(),
we pass a VMSTOP macro as the 'reason' argument. This is not ideal
because the VMSTOP macros tell why qemu stopped and not exactly
what the current VM state is.

One example to demonstrate this problem is that vm_start() calls
vm_state_notify() with reason=0, which turns out to be VMSTOP_USER.

This commit fixes that by replacing the VMSTOP macros with a proper
state type called RunState.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2011-09-15 16:39:32 -03:00
Blue Swirl 6115c0a82d kvm: remove unnecessary assignments
Avoid these warnings from clang analyzer:
/src/qemu/target-i386/kvm.c:772:5: warning: Value stored to 'cwd' is never read
    cwd = swd = twd = 0;
/src/qemu/target-i386/kvm.c:772:11: warning: Although the value stored to 'swd' is used in the enclosing expression, the value is never actually read from 'swd'
    cwd = swd = twd = 0;

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2011-09-10 14:50:00 +00:00
Stefan Weil 541dc0d47f Use new macro QEMU_PACKED for packed structures
Most changes were made using these commands:

git grep -la '__attribute__((packed))'|xargs perl -pi -e 's/__attribute__\(\(packed\)\)/QEMU_PACKED/'
git grep -la '__attribute__ ((packed))'|xargs perl -pi -e 's/__attribute__ \(\(packed\)\)/QEMU_PACKED/'
git grep -la '__attribute__((__packed__))'|xargs perl -pi -e 's/__attribute__\(\(__packed__\)\)/QEMU_PACKED/'
git grep -la '__attribute__ ((__packed__))'|xargs perl -pi -e 's/__attribute__ \(\(__packed__\)\)/QEMU_PACKED/'
git grep -la '__attribute((packed))'|xargs perl -pi -e 's/__attribute\(\(packed\)\)/QEMU_PACKED/'

Whitespace in linux-user/syscall_defs.h was fixed manually
to avoid warnings from scripts/checkpatch.pl.

Manual changes were also applied to hw/pc.c.

I did not fix indentation with tabs in block/vvfat.c.
The patch will show 4 errors with scripts/checkpatch.pl.

Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2011-09-03 10:45:59 +00:00
Jan Kiszka fdc9c41a5a Fix up some style nits of last uq/master merge
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-08-25 09:21:35 +01:00
Anthony Liguori 7267c0947d Use glib memory allocation and free functions
qemu_malloc/qemu_free no longer exist after this commit.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-08-20 23:01:08 -05:00
Marcelo Tosatti ac363c9042 Remove #ifdef KVM_CAP_TSC_CONTROL
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-08-05 12:10:55 -03:00
Joerg Roedel e7429073ed qemu-x86: Set tsc_khz in kvm when supported
Make use of the KVM_TSC_CONTROL feature if available.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-08-05 12:04:27 -03:00
Andre Przywara 31e8c69697 KVM: Fix XSAVE feature bit enumeration
When iterating through the XSAVE feature enumeration CPUID leaf (0xD)
we should not stop at the first zero EAX, but instead keep scanning
since there are gaps in the enumeration (ECX=1 for instance).
This fixes the proper usage of AVX in KVM guests.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-06-20 15:26:21 -03:00
Jan Kiszka ba9bc59e1f kvm: x86: Pass KVMState to kvm_arch_get_supported_cpuid
kvm_arch_get_supported_cpuid checks for global cpuid restrictions, it
does not require any CPUState reference. Changing its interface allows
to call it before any VCPU is initialized.

CC: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-06-20 15:24:00 -03:00
Jan Kiszka e56ff191b6 kvm: x86: Drop KVM_CAP build dependencies
No longer needed with accompanied kernel headers.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-06-20 15:19:54 -03:00
Jan Kiszka 5802e066eb kvm: Drop CONFIG_KVM_PARA
The kvm_para.h header is now always available.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-06-20 15:16:45 -03:00
Jan Kiszka 42cc8fa620 kvm: x86: Save/restore FPU OP, IP and DP
These FPU states are properly maintained by KVM but not yet by TCG. So
far we unconditionally set them to 0 in the guest which may cause
state corruptions, though not with modern guests.

To avoid breaking backward migration, use a conditional subsection that
is only written if any of the three fields is non-zero. The guest's
FNINIT clears them frequently, and cleared IA32_MISC_ENABLE MSR[2]
reduces the probability of non-zero values further so that this
subsection is not expected to restrict migration in any common scenario.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-06-19 15:57:56 +03:00