Commit Graph

805 Commits

Author SHA1 Message Date
Radim Krčmář 21bc8dc5b7 KVM: VMX: fix build without CONFIG_SMP
'apic' is not defined if !CONFIG_X86_64 && !CONFIG_X86_LOCAL_APIC.
Posted interrupt makes no sense without CONFIG_SMP, and
CONFIG_X86_LOCAL_APIC will be set with it.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-23 22:28:48 +01:00
Linus Torvalds 37507717de Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 perf updates from Ingo Molnar:
 "This series tightens up RDPMC permissions: currently even highly
  sandboxed x86 execution environments (such as seccomp) have permission
  to execute RDPMC, which may leak various perf events / PMU state such
  as timing information and other CPU execution details.

  This 'all is allowed' RDPMC mode is still preserved as the
  (non-default) /sys/devices/cpu/rdpmc=2 setting.  The new default is
  that RDPMC access is only allowed if a perf event is mmap-ed (which is
  needed to correctly interpret RDPMC counter values in any case).

  As a side effect of these changes CR4 handling is cleaned up in the
  x86 code and a shadow copy of the CR4 value is added.

  The extra CR4 manipulation adds ~ <50ns to the context switch cost
  between rdpmc-capable and rdpmc-non-capable mms"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86: Add /sys/devices/cpu/rdpmc=2 to allow rdpmc for all tasks
  perf/x86: Only allow rdpmc if a perf_event is mapped
  perf: Pass the event to arch_perf_update_userpage()
  perf: Add pmu callbacks to track event mapping and unmapping
  x86: Add a comment clarifying LDT context switching
  x86: Store a per-cpu shadow copy of CR4
  x86: Clean up cr4 manipulation
2015-02-16 14:58:12 -08:00
Radim Krčmář dab2087def KVM: x86: fix build with !CONFIG_SMP
<asm/apic.h> isn't included directly and without CONFIG_SMP, an option
that automagically pulls it can't be enabled.

Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-10 08:53:18 +01:00
Andy Lutomirski 1e02ce4ccc x86: Store a per-cpu shadow copy of CR4
Context switches and TLB flushes can change individual bits of CR4.
CR4 reads take several cycles, so store a shadow copy of CR4 in a
per-cpu variable.

To avoid wasting a cache line, I added the CR4 shadow to
cpu_tlbstate, which is already touched in switch_mm.  The heaviest
users of the cr4 shadow will be switch_mm and __switch_to_xtra, and
__switch_to_xtra is called shortly after switch_mm during context
switch, so the cacheline is likely to be hot.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Vince Weaver <vince@deater.net>
Cc: "hillf.zj" <hillf.zj@alibaba-inc.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/3a54dd3353fffbf84804398e00dfdc5b7c1afd7d.1414190806.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-04 12:10:42 +01:00
Andy Lutomirski 375074cc73 x86: Clean up cr4 manipulation
CR4 manipulation was split, seemingly at random, between direct
(write_cr4) and using a helper (set/clear_in_cr4).  Unfortunately,
the set_in_cr4 and clear_in_cr4 helpers also poke at the boot code,
which only a small subset of users actually wanted.

This patch replaces all cr4 access in functions that don't leave cr4
exactly the way they found it with new helpers cr4_set_bits,
cr4_clear_bits, and cr4_set_bits_and_update_boot.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Vince Weaver <vince@deater.net>
Cc: "hillf.zj" <hillf.zj@alibaba-inc.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/495a10bdc9e67016b8fd3945700d46cfd5c12c2f.1414190806.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-04 12:10:41 +01:00
Wincy Van 705699a139 KVM: nVMX: Enable nested posted interrupt processing
If vcpu has a interrupt in vmx non-root mode, injecting that interrupt
requires a vmexit.  With posted interrupt processing, the vmexit
is not needed, and interrupts are fully taken care of by hardware.
In nested vmx, this feature avoids much more vmexits than non-nested vmx.

When L1 asks L0 to deliver L1's posted interrupt vector, and the target
VCPU is in non-root mode, we use a physical ipi to deliver POSTED_INTR_NV
to the target vCPU.  Using POSTED_INTR_NV avoids unexpected interrupts
if a concurrent vmexit happens and L1's vector is different with L0's.
The IPI triggers posted interrupt processing in the target physical CPU.

In case the target vCPU was not in guest mode, complete the posted
interrupt delivery on the next entry to L2.

Signed-off-by: Wincy Van <fanwenyi0529@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-03 17:15:08 +01:00
Wincy Van 608406e290 KVM: nVMX: Enable nested virtual interrupt delivery
With virtual interrupt delivery, the hardware lets KVM use a more
efficient mechanism for interrupt injection. This is an important feature
for nested VMX, because it reduces vmexits substantially and they are
much more expensive with nested virtualization.  This is especially
important for throughput-bound scenarios.

Signed-off-by: Wincy Van <fanwenyi0529@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-03 17:07:38 +01:00
Wincy Van 82f0dd4b27 KVM: nVMX: Enable nested apic register virtualization
We can reduce apic register virtualization cost with this feature,
it is also a requirement for virtual interrupt delivery and posted
interrupt processing.

Signed-off-by: Wincy Van <fanwenyi0529@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-03 17:07:03 +01:00
Wincy Van b9c237bb1d KVM: nVMX: Make nested control MSRs per-cpu
To enable nested apicv support, we need per-cpu vmx
control MSRs:
  1. If in-kernel irqchip is enabled, we can enable nested
     posted interrupt, we should set posted intr bit in
     the nested_vmx_pinbased_ctls_high.
  2. If in-kernel irqchip is disabled, we can not enable
     nested posted interrupt, the posted intr bit
     in the nested_vmx_pinbased_ctls_high will be cleared.

Since there would be different settings about in-kernel
irqchip between VMs, different nested control MSRs
are needed.

Signed-off-by: Wincy Van <fanwenyi0529@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-03 17:06:51 +01:00
Wincy Van f2b93280ed KVM: nVMX: Enable nested virtualize x2apic mode
When L2 is using x2apic, we can use virtualize x2apic mode to
gain higher performance, especially in apicv case.

This patch also introduces nested_vmx_check_apicv_controls
for the nested apicv patches.

Signed-off-by: Wincy Van <fanwenyi0529@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-03 17:06:17 +01:00
Wincy Van 3af18d9c5f KVM: nVMX: Prepare for using hardware MSR bitmap
Currently, if L1 enables MSR_BITMAP, we will emulate this feature, all
of L2's msr access is intercepted by L0.  Features like "virtualize
x2apic mode" require that the MSR bitmap is enabled, or the hardware
will exit and for example not virtualize the x2apic MSRs.  In order to
let L1 use these features, we need to build a merged bitmap that only
not cause a VMEXIT if 1) L1 requires that 2) the bit is not required by
the processor for APIC virtualization.

For now the guests are still run with MSR bitmap disabled, but this
patch already introduces nested_vmx_merge_msr_bitmap for future use.

Signed-off-by: Wincy Van <fanwenyi0529@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-03 17:02:32 +01:00
Marcelo Tosatti 2e6d015799 KVM: x86: revert "add method to test PIR bitmap vector"
Revert 7c6a98dfa1, given
that testing PIR is not necessary anymore.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-02 18:36:34 +01:00
Paolo Bonzini ad15a29647 kvm: vmx: fix oops with explicit flexpriority=0 option
A function pointer was not NULLed, causing kvm_vcpu_reload_apic_access_page to
go down the wrong path and OOPS when doing put_page(NULL).

This did not happen on old processors, only when setting the module option
explicitly.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-30 16:18:49 +01:00
Kai Huang 843e433057 KVM: VMX: Add PML support in VMX
This patch adds PML support in VMX. A new module parameter 'enable_pml' is added
to allow user to enable/disable it manually.

Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-30 09:39:54 +01:00
Rickard Strandqvist 0c55d6d931 x86: kvm: vmx: Remove some unused functions
Removes some functions that are not used anywhere:
cpu_has_vmx_eptp_writeback() cpu_has_vmx_eptp_uncacheable()

This was partially found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-19 11:09:36 +01:00
Paolo Bonzini ad896af0b5 KVM: x86: mmu: remove argument to kvm_init_shadow_mmu and kvm_init_shadow_ept_mmu
The initialization function in mmu.c can always use walk_mmu, which
is known to be vcpu->arch.mmu.  Only init_kvm_nested_mmu is used to
initialize vcpu->arch.nested_mmu.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08 22:48:02 +01:00
Marcelo Tosatti 7c6a98dfa1 KVM: x86: add method to test PIR bitmap vector
kvm_x86_ops->test_posted_interrupt() returns true/false depending
whether 'vector' is set.

Next patch makes use of this interface.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08 22:45:18 +01:00
Tiejun Chen b4eef9b36d kvm: x86: vmx: NULL out hwapic_isr_update() in case of !enable_apicv
In most cases calling hwapic_isr_update(), we always check if
kvm_apic_vid_enabled() == 1, but actually,
kvm_apic_vid_enabled()
    -> kvm_x86_ops->vm_has_apicv()
        -> vmx_vm_has_apicv() or '0' in svm case
            -> return enable_apicv && irqchip_in_kernel(kvm)

So its a little cost to recall vmx_vm_has_apicv() inside
hwapic_isr_update(), here just NULL out hwapic_isr_update() in
case of !enable_apicv inside hardware_setup() then make all
related stuffs follow this. Note we don't check this under that
condition of irqchip_in_kernel() since we should make sure
definitely any caller don't work  without in-kernel irqchip.

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08 22:45:17 +01:00
Eugene Korenevsky 19d5f10b3a KVM: nVMX: consult PFEC_MASK and PFEC_MATCH when generating #PF VM-exit
When generating #PF VM-exit, check equality:
(PFEC & PFEC_MASK) == PFEC_MATCH
If there is equality, the 14 bit of exception bitmap is used to take decision
about generating #PF VM-exit. If there is inequality, inverted 14 bit is used.

Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08 22:45:16 +01:00
Eugene Korenevsky e9ac033e6b KVM: nVMX: Improve nested msr switch checking
This patch improve checks required by Intel Software Developer Manual.
 - SMM MSRs are not allowed.
 - microcode MSRs are not allowed.
 - check x2apic MSRs only when LAPIC is in x2apic mode.
 - MSR switch areas must be aligned to 16 bytes.
 - address of first and last byte in MSR switch areas should not set any bits
   beyond the processor's physical-address width.

Also it adds warning messages on failures during MSR switch. These messages
are useful for people who debug their VMMs in nVMX.

Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08 22:45:15 +01:00
Wincy Van ff651cb613 KVM: nVMX: Add nested msr load/restore algorithm
Several hypervisors need MSR auto load/restore feature.
We read MSRs from VM-entry MSR load area which specified by L1,
and load them via kvm_set_msr in the nested entry.
When nested exit occurs, we get MSRs via kvm_get_msr, writing
them to L1`s MSR store area. After this, we read MSRs from VM-exit
MSR load area, and load them via kvm_set_msr.

Signed-off-by: Wincy Van <fanwenyi0529@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-08 22:45:14 +01:00
Tiejun Chen baa035227b kvm: x86: vmx: reorder some msr writing
The commit 34a1cd60d1, "x86: vmx: move some vmx setting from
vmx_init() to hardware_setup()", tried to refactor some codes
specific to vmx hardware setting into hardware_setup(), but some
msr writing should depend on our previous setting condition like
enable_apicv, enable_ept and so on.

Reported-by: Jamie Heilman <jamie@audible.transient.net>
Tested-by: Jamie Heilman <jamie@audible.transient.net>
Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-27 21:52:10 +01:00
Bandan Das 78051e3b7e KVM: nVMX: Disable unrestricted mode if ept=0
If L0 has disabled EPT, don't advertise unrestricted
mode at all since it depends on EPT to run real mode code.

Fixes: 92fbc7b195
Cc: stable@vger.kernel.org
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-11 12:26:15 +01:00
Wanpeng Li 81dc01f749 kvm: vmx: add nested virtualization support for xsaves
Add nested virtualization support for xsaves.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:57:44 +01:00
Wanpeng Li 203000993d kvm: vmx: add MSR logic for XSAVES
Add logic to get/set the XSS model-specific register.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:57:39 +01:00
Wanpeng Li f53cd63c2d kvm: x86: handle XSAVES vmcs and vmexit
Initialize the XSS exit bitmap.  It is zero so there should be no XSAVES
or XRSTORS exits.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:57:33 +01:00
Wanpeng Li 55412b2eda kvm: x86: Add kvm_x86_ops hook that enables XSAVES for guest
Expose the XSAVES feature to the guest if the kvm_x86_ops say it is
available.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-05 13:57:16 +01:00
Tiejun Chen 81ed33e4aa kvm: x86: vmx: cleanup handle_ept_violation
Instead, just use PFERR_{FETCH, PRESENT, WRITE}_MASK
inside handle_ept_violation() for slightly better code.

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-18 11:07:53 +01:00
Andy Lutomirski 54b98bff8e x86, kvm, vmx: Don't set LOAD_IA32_EFER when host and guest match
There's nothing to switch if the host and guest values are the same.
I am unable to find evidence that this makes any difference
whatsoever.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
[I could see a difference on Nehalem.  From 5 runs:

 userspace exit, guest!=host   12200 11772 12130 12164 12327
 userspace exit, guest=host    11983 11780 11920 11919 12040
 lightweight exit, guest!=host  3214  3220  3238  3218  3337
 lightweight exit, guest=host   3178  3193  3193  3187  3220

 This passes the t-test with 99% confidence for userspace exit,
 98.5% confidence for lightweight exit. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-12 16:27:21 +01:00
Andy Lutomirski f6577a5fa1 x86, kvm, vmx: Always use LOAD_IA32_EFER if available
At least on Sandy Bridge, letting the CPU switch IA32_EFER is much
faster than switching it manually.

I benchmarked this using the vmexit kvm-unit-test (single run, but
GOAL multiplied by 5 to do more iterations):

Test                                  Before      After    Change
cpuid                                   2000       1932    -3.40%
vmcall                                  1914       1817    -5.07%
mov_from_cr8                              13         13     0.00%
mov_to_cr8                                19         19     0.00%
inl_from_pmtimer                       19164      10619   -44.59%
inl_from_qemu                          15662      10302   -34.22%
inl_from_kernel                         3916       3802    -2.91%
outl_to_kernel                          2230       2194    -1.61%
mov_dr                                   172        176     2.33%
ipi                                (skipped)  (skipped)
ipi+halt                           (skipped)  (skipped)
ple-round-robin                           13         13     0.00%
wr_tsc_adjust_msr                       1920       1845    -3.91%
rd_tsc_adjust_msr                       1892       1814    -4.12%
mmio-no-eventfd:pci-mem                16394      11165   -31.90%
mmio-wildcard-eventfd:pci-mem           4607       4645     0.82%
mmio-datamatch-eventfd:pci-mem          4601       4610     0.20%
portio-no-eventfd:pci-io               11507       7942   -30.98%
portio-wildcard-eventfd:pci-io          2239       2225    -0.63%
portio-datamatch-eventfd:pci-io         2250       2234    -0.71%

I haven't explicitly computed the significance of these numbers,
but this isn't subtle.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
[The results were reproducible on all of Nehalem, Sandy Bridge and
 Ivy Bridge.  The slowness of manual switching is because writing
 to EFER with WRMSR triggers a TLB flush, even if the only bit you're
 touching is SCE (so the page table format is not affected).  Doing
 the write as part of vmentry/vmexit, instead, does not flush the TLB,
 probably because all processors that have EPT also have VPID. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-12 12:35:02 +01:00
Nadav Amit 82b32774c2 KVM: x86: Breakpoints do not consider CS.base
x86 debug registers hold a linear address. Therefore, breakpoints detection
should consider CS.base, and check whether instruction linear address equals
(CS.base + RIP). This patch introduces a function to evaluate RIP linear
address and uses it for breakpoints detection.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-07 15:44:04 +01:00
Nadav Amit 7305eb5d8c KVM: x86: Clear DR6[0:3] on #DB during handle_dr
DR6[0:3] (previous breakpoint indications) are cleared when #DB is injected
during handle_exception, just as real hardware does.  Similarily, handle_dr
should clear DR6[0:3].

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-07 15:44:03 +01:00
Wei Wang 4114c27d45 KVM: x86: reset RVI upon system reset
A bug was reported as follows: when running Windows 7 32-bit guests on qemu-kvm,
sometimes the guests run into blue screen during reboot. The problem was that a
guest's RVI was not cleared when it rebooted. This patch has fixed the problem.

Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Tested-by: Rongrong Liu <rongrongx.liu@intel.com>, Da Chun <ngugc@qq.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-07 15:44:00 +01:00
Paolo Bonzini a2ae9df7c9 kvm: x86: vmx: avoid returning bool to distinguish success from error
Return a negative error code instead, and WARN() when we should be covering
the entire 2-bit space of vmcs_field_type's return value.  For increased
robustness, add a BUILD_BUG_ON checking the range of vmcs_field_to_offset.

Suggested-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-07 15:44:00 +01:00
Tiejun Chen 34a1cd60d1 kvm: x86: vmx: move some vmx setting from vmx_init() to hardware_setup()
Instead of vmx_init(), actually it would make reasonable sense to do
anything specific to vmx hardware setting in vmx_x86_ops->hardware_setup().

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-07 15:43:59 +01:00
Tiejun Chen f2c7648d91 kvm: x86: vmx: move down hardware_setup() and hardware_unsetup()
Just move this pair of functions down to make sure later we can
add something dependent on others.

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-07 15:43:59 +01:00
Nadav Amit 16f8a6f979 KVM: vmx: Unavailable DR4/5 is checked before CPL
If DR4/5 is accessed when it is unavailable (since CR4.DE is set), then #UD
should be generated even if CPL>0. This is according to Intel SDM Table 6-2:
"Priority Among Simultaneous Exceptions and Interrupts".

Note, that this may happen on the first DR access, even if the host does not
sets debug breakpoints. Obviously, it occurs when the host debugs the guest.

This patch moves the DR4/5 checks from __kvm_set_dr/_kvm_get_dr to handle_dr.
The emulator already checks DR4/5 availability in check_dr_read. Nested
virutalization related calls to kvm_set_dr/kvm_get_dr would not like to inject
exceptions to the guest.

As for SVM, the patch follows the previous logic as much as possible. Anyhow,
it appears the DR interception code might be buggy - even if the DR access
may cause an exception, the instruction is skipped.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03 12:07:26 +01:00
Nadav Amit 0e8a09969a KVM: x86: Clear DR7.LE during task-switch
DR7.LE should be cleared during task-switch. This feature is poorly documented.
For reference, see:
http://pdos.csail.mit.edu/6.828/2005/readings/i386/s12_02.htm

SDM [17.2.4]:
  This feature is not supported in the P6 family processors, later IA-32
  processors, and Intel 64 processors.

AMD [2:13.1.1.4]:
  This bit is ignored by implementations of the AMD64 architecture.

Intel's formulation could mean that it isn't even zeroed, but current
hardware indeed does not behave like that.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03 12:07:25 +01:00
Nadav Amit 6bdf06625d KVM: x86: DR7.GD should be cleared upon any #DB exception
Intel SDM 17.2.4 (Debug Control Register (DR7)) says: "The processor clears the
GD flag upon entering to the debug exception handler." This sentence may be
misunderstood as if it happens only on #DB due to debug-register protection,
but it happens regardless to the cause of the #DB.

Fix the behavior to match both real hardware and Bochs.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03 12:07:23 +01:00
Andy Lutomirski 52ce3c21ae x86,kvm,vmx: Don't trap writes to CR4.TSD
CR4.TSD is guest-owned; don't trap writes to it in VMX guests.  This
avoids a VM exit on context switches into or out of a PR_TSC_SIGSEGV
task.

I think that this fixes an unintentional side-effect of:
    4c38609ac5 KVM: VMX: Make guest cr4 mask more conservative

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-03 12:07:22 +01:00
Paolo Bonzini a73896cb5b KVM: vmx: defer load of APIC access page address during reset
Most call paths to vmx_vcpu_reset do not hold the SRCU lock.  Defer loading
the APIC access page to the next vmentry.

This avoids the following lockdep splat:

[ INFO: suspicious RCU usage. ]
3.18.0-rc2-test2+ #70 Not tainted
-------------------------------
include/linux/kvm_host.h:474 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
1 lock held by qemu-system-x86/2371:
 #0:  (&vcpu->mutex){+.+...}, at: [<ffffffffa037d800>] vcpu_load+0x20/0xd0 [kvm]

stack backtrace:
CPU: 4 PID: 2371 Comm: qemu-system-x86 Not tainted 3.18.0-rc2-test2+ #70
Hardware name: Dell Inc. OptiPlex 9010/0M9KCM, BIOS A12 01/10/2013
 0000000000000001 ffff880209983ca8 ffffffff816f514f 0000000000000000
 ffff8802099b8990 ffff880209983cd8 ffffffff810bd687 00000000000fee00
 ffff880208a2c000 ffff880208a10000 ffff88020ef50040 ffff880209983d08
Call Trace:
 [<ffffffff816f514f>] dump_stack+0x4e/0x71
 [<ffffffff810bd687>] lockdep_rcu_suspicious+0xe7/0x120
 [<ffffffffa037d055>] gfn_to_memslot+0xd5/0xe0 [kvm]
 [<ffffffffa03807d3>] __gfn_to_pfn+0x33/0x60 [kvm]
 [<ffffffffa0380885>] gfn_to_page+0x25/0x90 [kvm]
 [<ffffffffa038aeec>] kvm_vcpu_reload_apic_access_page+0x3c/0x80 [kvm]
 [<ffffffffa08f0a9c>] vmx_vcpu_reset+0x20c/0x460 [kvm_intel]
 [<ffffffffa039ab8e>] kvm_vcpu_reset+0x15e/0x1b0 [kvm]
 [<ffffffffa039ac0c>] kvm_arch_vcpu_setup+0x2c/0x50 [kvm]
 [<ffffffffa037f7e0>] kvm_vm_ioctl+0x1d0/0x780 [kvm]
 [<ffffffff810bc664>] ? __lock_is_held+0x54/0x80
 [<ffffffff812231f0>] do_vfs_ioctl+0x300/0x520
 [<ffffffff8122ee45>] ? __fget+0x5/0x250
 [<ffffffff8122f0fa>] ? __fget_light+0x2a/0xe0
 [<ffffffff81223491>] SyS_ioctl+0x81/0xa0
 [<ffffffff816fed6d>] system_call_fastpath+0x16/0x1b

Reported-by: Takashi Iwai <tiwai@suse.de>
Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Reviewed-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Tested-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Fixes: 38b9917350
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-02 08:37:18 +01:00
Jan Kiszka 282da870f4 KVM: nVMX: Disable preemption while reading from shadow VMCS
In order to access the shadow VMCS, we need to load it. At this point,
vmx->loaded_vmcs->vmcs and the actually loaded one start to differ. If
we now get preempted by Linux, vmx_vcpu_put and, on return, the
vmx_vcpu_load will work against the wrong vmcs. That can cause
copy_shadow_to_vmcs12 to corrupt the vmcs12 state.

Fix the issue by disabling preemption during the copy operation.
copy_vmcs12_to_shadow is safe from this issue as it is executed by
vmx_vcpu_run when preemption is already disabled before vmentry.

This bug is exposed by running Jailhouse within KVM on CPUs with
shadow VMCS support.  Jailhouse never expects an interrupt pending
vmexit, but the bug can cause it if, after copy_shadow_to_vmcs12
is preempted, the active VMCS happens to have the virtual interrupt
pending flag set in the CPU-based execution controls.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-11-02 07:55:46 +01:00
Michael S. Tsirkin 2bc19dc375 kvm: x86: don't kill guest on unknown exit reason
KVM_EXIT_UNKNOWN is a kvm bug, we don't really know whether it was
triggered by a priveledged application.  Let's not kill the guest: WARN
and inject #UD instead.

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24 13:21:17 +02:00
Petr Matousek a642fc3050 kvm: vmx: handle invvpid vm exit gracefully
On systems with invvpid instruction support (corresponding bit in
IA32_VMX_EPT_VPID_CAP MSR is set) guest invocation of invvpid
causes vm exit, which is currently not handled and results in
propagation of unknown exit to userspace.

Fix this by installing an invvpid vm exit handler.

This is CVE-2014-3646.

Cc: stable@vger.kernel.org
Signed-off-by: Petr Matousek <pmatouse@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24 13:21:17 +02:00
Andy Honig 8b3c3104c3 KVM: x86: Prevent host from panicking on shared MSR writes.
The previous patch blocked invalid writes directly when the MSR
is written.  As a precaution, prevent future similar mistakes by
gracefulling handle GPs caused by writes to shared MSRs.

Cc: stable@vger.kernel.org
Signed-off-by: Andrew Honig <ahonig@google.com>
[Remove parts obsoleted by Nadav's patch. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24 13:21:08 +02:00
Nadav Amit 854e8bb1aa KVM: x86: Check non-canonical addresses upon WRMSR
Upon WRMSR, the CPU should inject #GP if a non-canonical value (address) is
written to certain MSRs. The behavior is "almost" identical for AMD and Intel
(ignoring MSRs that are not implemented in either architecture since they would
anyhow #GP). However, IA32_SYSENTER_ESP and IA32_SYSENTER_EIP cause #GP if
non-canonical address is written on Intel but not on AMD (which ignores the top
32-bits).

Accordingly, this patch injects a #GP on the MSRs which behave identically on
Intel and AMD.  To eliminate the differences between the architecutres, the
value which is written to IA32_SYSENTER_ESP and IA32_SYSENTER_EIP is turned to
canonical value before writing instead of injecting a #GP.

Some references from Intel and AMD manuals:

According to Intel SDM description of WRMSR instruction #GP is expected on
WRMSR "If the source register contains a non-canonical address and ECX
specifies one of the following MSRs: IA32_DS_AREA, IA32_FS_BASE, IA32_GS_BASE,
IA32_KERNEL_GS_BASE, IA32_LSTAR, IA32_SYSENTER_EIP, IA32_SYSENTER_ESP."

According to AMD manual instruction manual:
LSTAR/CSTAR (SYSCALL): "The WRMSR instruction loads the target RIP into the
LSTAR and CSTAR registers.  If an RIP written by WRMSR is not in canonical
form, a general-protection exception (#GP) occurs."
IA32_GS_BASE and IA32_FS_BASE (WRFSBASE/WRGSBASE): "The address written to the
base field must be in canonical form or a #GP fault will occur."
IA32_KERNEL_GS_BASE (SWAPGS): "The address stored in the KernelGSbase MSR must
be in canonical form."

This patch fixes CVE-2014-3610.

Cc: stable@vger.kernel.org
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-24 13:21:08 +02:00
Andy Lutomirski d974baa398 x86,kvm,vmx: Preserve CR4 across VM entry
CR4 isn't constant; at least the TSD and PCE bits can vary.

TBH, treating CR0 and CR3 as constant scares me a bit, too, but it looks
like it's correct.

This adds a branch and a read from cr4 to each vm entry.  Because it is
extremely likely that consecutive entries into the same vcpu will have
the same host cr4 value, this fixes up the vmcs instead of restoring cr4
after the fact.  A subsequent patch will add a kernel-wide cr4 shadow,
reducing the overhead in the common case to just two memory reads and a
branch.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Cc: Petr Matousek <pmatouse@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-18 10:09:03 -07:00
Linus Torvalds 0429fbc0bd Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu consistent-ops changes from Tejun Heo:
 "Way back, before the current percpu allocator was implemented, static
  and dynamic percpu memory areas were allocated and handled separately
  and had their own accessors.  The distinction has been gone for many
  years now; however, the now duplicate two sets of accessors remained
  with the pointer based ones - this_cpu_*() - evolving various other
  operations over time.  During the process, we also accumulated other
  inconsistent operations.

  This pull request contains Christoph's patches to clean up the
  duplicate accessor situation.  __get_cpu_var() uses are replaced with
  with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr().

  Unfortunately, the former sometimes is tricky thanks to C being a bit
  messy with the distinction between lvalues and pointers, which led to
  a rather ugly solution for cpumask_var_t involving the introduction of
  this_cpu_cpumask_var_ptr().

  This converts most of the uses but not all.  Christoph will follow up
  with the remaining conversions in this merge window and hopefully
  remove the obsolete accessors"

* 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits)
  irqchip: Properly fetch the per cpu offset
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix
  ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write.
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t
  Revert "powerpc: Replace __get_cpu_var uses"
  percpu: Remove __this_cpu_ptr
  clocksource: Replace __this_cpu_ptr with raw_cpu_ptr
  sparc: Replace __get_cpu_var uses
  avr32: Replace __get_cpu_var with __this_cpu_write
  blackfin: Replace __get_cpu_var uses
  tile: Use this_cpu_ptr() for hardware counters
  tile: Replace __get_cpu_var uses
  powerpc: Replace __get_cpu_var uses
  alpha: Replace __get_cpu_var
  ia64: Replace __get_cpu_var uses
  s390: cio driver &__get_cpu_var replacements
  s390: Replace __get_cpu_var uses
  mips: Replace __get_cpu_var uses
  MIPS: Replace __get_cpu_var uses in FPU emulator.
  arm: Replace __this_cpu_ptr with raw_cpu_ptr
  ...
2014-10-15 07:48:18 +02:00
Tang Chen c24ae0dcd3 kvm: x86: Unpin and remove kvm_arch->apic_access_page
In order to make the APIC access page migratable, stop pinning it in
memory.

And because the APIC access page is not pinned in memory, we can
remove kvm_arch->apic_access_page.  When we need to write its
physical address into vmcs, we use gfn_to_page() to get its page
struct, which is needed to call page_to_phys(); the page is then
immediately unpinned.

Suggested-by: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-24 14:08:01 +02:00
Tang Chen 38b9917350 kvm: vmx: Implement set_apic_access_page_addr
Currently, the APIC access page is pinned by KVM for the entire life
of the guest.  We want to make it migratable in order to make memory
hot-unplug available for machines that run KVM.

This patch prepares to handle this for the case where there is no nested
virtualization, or where the nested guest does not have an APIC page of
its own.  All accesses to kvm->arch.apic_access_page are changed to go
through kvm_vcpu_reload_apic_access_page.

If the APIC access page is invalidated when the host is running, we update
the VMCS in the next guest entry.

If it is invalidated when the guest is running, the MMU notifier will force
an exit, after which we will handle everything as in the previous case.

If it is invalidated when a nested guest is running, the request will update
either the VMCS01 or the VMCS02.  Updating the VMCS01 is done at the
next L2->L1 exit, while updating the VMCS02 is done in prepare_vmcs02.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-24 14:08:01 +02:00
Tiejun Chen b461966063 kvm: x86: fix two typos in comment
s/drity/dirty and s/vmsc01/vmcs01

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-24 14:07:53 +02:00
Nadav Amit 4566654bb9 KVM: vmx: Inject #GP on invalid PAT CR
Guest which sets the PAT CR to invalid value should get a #GP.  Currently, if
vmx supports loading PAT CR during entry, then the value is not checked.  This
patch makes the required check in that case.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-24 14:07:52 +02:00
Liang Chen 77c3913b74 KVM: x86: directly use kvm_make_request again
A one-line wrapper around kvm_make_request is not particularly
useful. Replace kvm_mmu_flush_tlb() with kvm_make_request().

Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-24 14:07:51 +02:00
Marcelo Tosatti bc6134942d KVM: nested VMX: disable perf cpuid reporting
Initilization of L2 guest with -cpu host, on L1 guest with -cpu host
triggers:

(qemu) KVM: entry failed, hardware error 0x7
...
nested_vmx_run: VMCS MSR_{LOAD,STORE} unsupported

Nested VMX MSR load/store support is not sufficient to
allow perf for L2 guest.

Until properly fixed, trap CPUID and disable function 0xA.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-24 14:07:50 +02:00
Paolo Bonzini 1f755a8275 kvm: Make init_rmode_tss() return 0 on success.
In init_rmode_tss(), there two variables indicating the return
value, r and ret, and it return 0 on error, 1 on success. The function
is only called by vmx_set_tss_addr(), and ret is redundant.

This patch removes the redundant variable, by making init_rmode_tss()
return 0 on success, -errno on failure.

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-24 14:07:48 +02:00
Tang Chen f51770ed46 kvm: Make init_rmode_identity_map() return 0 on success.
In init_rmode_identity_map(), there two variables indicating the return
value, r and ret, and it return 0 on error, 1 on success. The function
is only called by vmx_create_vcpu(), and ret is redundant.

This patch removes the redundant variable, and makes init_rmode_identity_map()
return 0 on success, -errno on failure.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-17 13:10:12 +02:00
Tang Chen a255d4795f kvm: Remove ept_identity_pagetable from struct kvm_arch.
kvm_arch->ept_identity_pagetable holds the ept identity pagetable page. But
it is never used to refer to the page at all.

In vcpu initialization, it indicates two things:
1. indicates if ept page is allocated
2. indicates if a memory slot for identity page is initialized

Actually, kvm_arch->ept_identity_pagetable_done is enough to tell if the ept
identity pagetable is initialized. So we can remove ept_identity_pagetable.

NOTE: In the original code, ept identity pagetable page is pinned in memroy.
      As a result, it cannot be migrated/hot-removed. After this patch, since
      kvm_arch->ept_identity_pagetable is removed, ept identity pagetable page
      is no longer pinned in memory. And it can be migrated/hot-removed.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-17 13:10:11 +02:00
Tang Chen 73a6d94162 kvm: Use APIC_DEFAULT_PHYS_BASE macro as the apic access page address.
We have APIC_DEFAULT_PHYS_BASE defined as 0xfee00000, which is also the address of
apic access page. So use this macro.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-11 11:10:22 +02:00
Radim Krčmář 13a34e067e KVM: remove garbage arg to *hardware_{en,dis}able
In the beggining was on_each_cpu(), which required an unused argument to
kvm_arch_ops.hardware_{en,dis}able, but this was soon forgotten.

Remove unnecessary arguments that stem from this.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 16:35:55 +02:00
Paolo Bonzini 48d89b9260 KVM: x86: fix some sparse warnings
Sparse reports the following easily fixed warnings:

   arch/x86/kvm/vmx.c:8795:48: sparse: Using plain integer as NULL pointer
   arch/x86/kvm/vmx.c:2138:5: sparse: symbol vmx_read_l1_tsc was not declared. Should it be static?
   arch/x86/kvm/vmx.c:6151:48: sparse: Using plain integer as NULL pointer
   arch/x86/kvm/vmx.c:8851:6: sparse: symbol vmx_sched_in was not declared. Should it be static?

   arch/x86/kvm/svm.c:2162:5: sparse: symbol svm_read_l1_tsc was not declared. Should it be static?

Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 14:02:49 +02:00
Wanpeng Li a7c0b07d57 KVM: nVMX: nested TPR shadow/threshold emulation
This patch fix bug https://bugzilla.kernel.org/show_bug.cgi?id=61411

TPR shadow/threshold feature is important to speed up the Windows guest.
Besides, it is a must feature for certain VMM.

We map virtual APIC page address and TPR threshold from L1 VMCS. If
TPR_BELOW_THRESHOLD VM exit is triggered by L2 guest and L1 interested
in, we inject it into L1 VMM for handling.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
[Add PAGE_ALIGNED check, do not write useless virtual APIC page address
 if TPR shadowing is disabled. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 14:02:48 +02:00
Wanpeng Li a2bcba5035 KVM: nVMX: introduce nested_get_vmcs12_pages
Introduce function nested_get_vmcs12_pages() to check the valid
of nested apic access page and virtual apic page earlier.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-29 14:02:48 +02:00
Christoph Lameter 89cbc76768 x86: Replace __get_cpu_var uses
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	__this_cpu_inc(y)

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-26 13:45:49 -04:00
Radim Krčmář 7b46268d29 KVM: trace kvm_ple_window grow/shrink
Tracepoint for dynamic PLE window, fired on every potential change.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-21 18:45:23 +02:00
Radim Krčmář b4a2d31da8 KVM: VMX: dynamise PLE window
Window is increased on every PLE exit and decreased on every sched_in.
The idea is that we don't want to PLE exit if there is no preemption
going on.
We do this with sched_in() because it does not hold rq lock.

There are two new kernel parameters for changing the window:
 ple_window_grow and ple_window_shrink
ple_window_grow affects the window on PLE exit and ple_window_shrink
does it on sched_in;  depending on their value, the window is modifier
like this: (ple_window is kvm_intel's global)

  ple_window_shrink/ |
  ple_window_grow    | PLE exit           | sched_in
  -------------------+--------------------+---------------------
  < 1                |  = ple_window      |  = ple_window
  < ple_window       | *= ple_window_grow | /= ple_window_shrink
  otherwise          | += ple_window_grow | -= ple_window_shrink

A third new parameter, ple_window_max, controls the maximal ple_window;
it is internally rounded down to a closest multiple of ple_window_grow.

VCPU's PLE window is never allowed below ple_window.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-21 18:45:23 +02:00
Radim Krčmář a7653ecdf3 KVM: VMX: make PLE window per-VCPU
Change PLE window into per-VCPU variable, seeded from module parameter,
to allow greater flexibility.

Brings in a small overhead on every vmentry.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-21 18:45:22 +02:00
Radim Krčmář ae97a3b818 KVM: x86: introduce sched_in to kvm_x86_ops
sched_in preempt notifier is available for x86, allow its use in
specific virtualization technlogies as well.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-21 18:45:22 +02:00
Wanpeng Li a32e84594d KVM: vmx: fix ept reserved bits for 1-GByte page
EPT misconfig handler in kvm will check which reason lead to EPT
misconfiguration after vmexit. One of the reasons is that an EPT
paging-structure entry is configured with settings reserved for
future functionality. However, the handler can't identify if
paging-structure entry of reserved bits for 1-GByte page are
configured, since PDPTE which point to 1-GByte page will reserve
bits 29:12 instead of bits 7:3 which are reserved for PDPTE that
references an EPT Page Directory. This patch fix it by reserve
bits 29:12 for 1-GByte page.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-20 10:13:40 +02:00
Monam Agarwal 3b63a43f1e arch/x86: Use RCU_INIT_POINTER(x, NULL) in kvm/vmx.c
Here rcu_assign_pointer() is ensuring that the
initialization of a structure is carried out before storing a pointer
to that structure.
So, rcu_assign_pointer(p, NULL) can always safely be converted to
RCU_INIT_POINTER(p, NULL).

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-19 15:12:29 +02:00
Wanpeng Li 4473b570a7 KVM: x86: drop fpu_activate hook
The only user of the fpu_activate hook was dropped in commit
2d04a05bd7 (KVM: x86 emulator: emulate CLTS internally, 2011-04-20).
vmx_fpu_activate and svm_fpu_activate are still called on #NM (and for
Intel CLTS), but never from common code; hence, there's no need for
a hook.

Reviewed-by: Yang Zhang <yang.z.zhang@intel.com>
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-19 15:12:28 +02:00
Wanpeng Li f3380ca5d7 KVM: nVMX: Fix nested vmexit ack intr before load vmcs01
An external interrupt will cause a vmexit with reason "external interrupt"
when L2 is running.  L1 will pick up the interrupt through vmcs12 if
L1 set the ack interrupt bit.  Commit 77b0f5d (KVM: nVMX: Ack and write
vector info to intr_info if L1 asks us to) retrieves the interrupt that
belongs to L1 before vmcs01 is loaded.

This will lead to problems in the next patch, which would write to SVI
of vmcs02 instead of vmcs01 (SVI of vmcs02 doesn't make sense because
L2 runs without APICv).

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Liu, RongrongX <rongrongx.liu@intel.com>
Tested-by: Felipe Reyes <freyes@suse.com>
Fixes: 77b0f5d67f
Cc: stable@vger.kernel.org
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
[Move tracepoint as well. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-05 14:50:45 +02:00
Chris J Arges 296f047502 KVM: vmx: remove duplicate vmx_mpx_supported() prototype
Remove a prototype which was added by both 93c4adc7af and 36be0b9deb.

Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-30 17:43:57 +02:00
Paolo Bonzini 03916db934 Replace NR_VMX_MSR with its definition
Using ARRAY_SIZE directly makes it easier to read the code.  While touching
the code, replace the division by a multiplication in the recently added
BUILD_BUG_ON.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-24 14:21:57 +02:00
Nadav Amit 0123be429f KVM: x86: Assertions to check no overrun in MSR lists
Currently there is no check whether shared MSRs list overrun the allocated size
which can results in bugs. In addition there is no check that vmx->guest_msrs
has sufficient space to accommodate all the VMX msrs.  This patch adds the
assertions.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-24 14:16:57 +02:00
Nadav Amit 6f43ed01e8 KVM: x86: DR6/7.RTM cannot be written
Haswell and newer Intel CPUs have support for RTM, and in that case DR6.RTM is
not fixed to 1 and DR7.RTM is not fixed to zero. That is not the case in the
current KVM implementation. This bug is apparent only if the MOV-DR instruction
is emulated or the host also debugs the guest.

This patch is a partial fix which enables DR6.RTM and DR7.RTM to be cleared and
set respectively. It also sets DR6.RTM upon every debug exception. Obviously,
it is not a complete fix, as debugging of RTM is still unsupported.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-21 17:17:52 +02:00
Paolo Bonzini 9a2a05b9ed KVM: nVMX: clean up nested_release_vmcs12 and code around it
Make nested_release_vmcs12 idempotent.

Tested-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-21 14:29:49 +02:00
Paolo Bonzini 4fa7734c62 KVM: nVMX: fix lifetime issues for vmcs02
free_nested needs the loaded_vmcs to be valid if it is a vmcs02, in
order to detach it from the shadow vmcs.  However, this is not
available anymore after commit 26a865f4aa (KVM: VMX: fix use after
free of vmx->loaded_vmcs, 2014-01-03).

Revert that patch, and fix its problem by forcing a vmcs01 as the
active VMCS before freeing all the nested VMX state.

Reported-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Tested-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-21 14:29:49 +02:00
Wanpeng Li 963fee1656 KVM: nVMX: Fix virtual interrupt delivery injection
This patch fix bug reported in https://bugzilla.kernel.org/show_bug.cgi?id=73331,
after the patch http://www.spinics.net/lists/kvm/msg105230.html applied, there is
some progress and the L2 can boot up, however, slowly. The original idea of this
fix vid injection patch is from "Zhang, Yang Z" <yang.z.zhang@intel.com>.

Interrupt which delivered by vid should be injected to L1 by L0 if current is in
L1, or should be injected to L2 by L0 through the old injection way if L1 doesn't
have set External-interrupt exiting bit. The current logic doen't consider these
cases. This patch fix it by vid intr to L1 if current is L1 or L2 through old
injection way if L1 doen't have External-interrupt exiting bit set.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: "Zhang, Yang Z" <yang.z.zhang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-17 14:45:26 +02:00
Paolo Bonzini 37ccdcbe07 KVM: x86: return all bits from get_interrupt_shadow
For the next patch we will need to know the full state of the
interrupt shadow; we will then set KVM_REQ_EVENT when one bit
is cleared.

However, right now get_interrupt_shadow only returns the one
corresponding to the emulated instruction, or an unconditional
0 if the emulated instruction does not have an interrupt shadow.
This is confusing and does not allow us to check for cleared
bits as mentioned above.

Clean the callback up, and modify toggle_interruptibility to
match the comment above the call.  As a small result, the
call to set_interrupt_shadow will be skipped in the common
case where int_shadow == 0 && mask == 0.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-11 09:13:56 +02:00
Paolo Bonzini 98eb2f8b14 KVM: vmx: speed up emulation of invalid guest state
About 25% of the time spent in emulation of invalid guest state
is wasted in checking whether emulation is required for the next
instruction.  However, this almost never changes except when a
segment register (or TR or LDTR) changes, or when there is a mode
transition (i.e. CR0 changes).

In fact, vmx_set_segment and vmx_set_cr0 already modify
vmx->emulation_required (except that the former for some reason
uses |= instead of just an assignment).  So there is no need to
call guest_state_valid in the emulation loop.

Emulation performance test results indicate 1650-2600 cycles
for common instructions, versus 2300-3200 before this patch on
a Sandy Bridge Xeon.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-11 09:13:56 +02:00
Nadav Amit 27e6fb5dae KVM: vmx: vmx instructions handling does not consider cs.l
VMX instructions use 32-bit operands in 32-bit mode, and 64-bit operands in
64-bit mode.  The current implementation is broken since it does not use the
register operands correctly, and always uses 64-bit for reads and writes.
Moreover, write to memory in vmwrite only considers long-mode, so it ignores
cs.l. This patch fixes this behavior.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-19 12:52:15 +02:00
Nadav Amit 1e32c07955 KVM: vmx: handle_cr ignores 32/64-bit mode
On 32-bit mode only bits [31:0] of the CR should be used for setting the CR
value.  Otherwise, the host may incorrectly assume the value is invalid if bits
[63:32] are not zero.  Moreover, the CR is currently being read twice when CR8
is used.  Last, nested mov-cr exiting is modified to handle the CR value
correctly as well.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-19 12:52:15 +02:00
Nadav Amit 5777392e83 KVM: x86: check DR6/7 high-bits are clear only on long-mode
When the guest sets DR6 and DR7, KVM asserts the high 32-bits are clear, and
otherwise injects a #GP exception. This exception should only be injected only
if running in long-mode.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-19 12:52:14 +02:00
Jan Kiszka 5381417f6a KVM: nVMX: Fix returned value of MSR_IA32_VMX_VMCS_ENUM
Many real CPUs get this wrong as well, but ours is totally off: bits 9:1
define the highest index value.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-19 12:52:13 +02:00
Jan Kiszka 2996fca069 KVM: nVMX: Allow to disable VM_{ENTRY_LOAD,EXIT_SAVE}_DEBUG_CONTROLS
Allow L1 to "leak" its debug controls into L2, i.e. permit cleared
VM_{ENTRY_LOAD,EXIT_SAVE}_DEBUG_CONTROLS. This requires to manually
transfer the state of DR7 and IA32_DEBUGCTLMSR from L1 into L2 as both
run on different VMCS.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-19 12:52:13 +02:00
Jan Kiszka 560b7ee12c KVM: nVMX: Fix returned value of MSR_IA32_VMX_PROCBASED_CTLS
SDM says bits 1, 4-6, 8, 13-16, and 26 have to be set.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-19 12:52:12 +02:00
Jan Kiszka 3dcdf3ec6e KVM: nVMX: Allow to disable CR3 access interception
We already have this control enabled by exposing a broken
MSR_IA32_VMX_PROCBASED_CTLS value. This will properly advertise our
capability once the value is fixed by clearing the right bits in
MSR_IA32_VMX_TRUE_PROCBASED_CTLS. We also have to ensure to test the
right value on L2 entry.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-19 12:52:12 +02:00
Jan Kiszka 3dbcd8da7b KVM: nVMX: Advertise support for MSR_IA32_VMX_TRUE_*_CTLS
We already implemented them but failed to advertise them. Currently they
all return the identical values to the capability MSRs they are
augmenting. So there is no change in exposed features yet.

Drop related comments at this chance that are partially incorrect and
redundant anyway.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-19 12:52:11 +02:00
Fabian Frederick bc39c4db71 arch/x86/kvm/vmx.c: use PAGE_ALIGNED instead of IS_ALIGNED(PAGE_SIZE
use mm.h definition

Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-19 12:52:08 +02:00
Linus Torvalds b05d59dfce At over 200 commits, covering almost all supported architectures, this
was a pretty active cycle for KVM.  Changes include:
 
 - a lot of s390 changes: optimizations, support for migration,
   GDB support and more
 
 - ARM changes are pretty small: support for the PSCI 0.2 hypercall
   interface on both the guest and the host (the latter acked by Catalin)
 
 - initial POWER8 and little-endian host support
 
 - support for running u-boot on embedded POWER targets
 
 - pretty large changes to MIPS too, completing the userspace interface
   and improving the handling of virtualized timer hardware
 
 - for x86, a larger set of changes is scheduled for 3.17.  Still,
   we have a few emulator bugfixes and support for running nested
   fully-virtualized Xen guests (para-virtualized Xen guests have
   always worked).  And some optimizations too.
 
 The only missing architecture here is ia64.  It's not a coincidence
 that support for KVM on ia64 is scheduled for removal in 3.17.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm into next

Pull KVM updates from Paolo Bonzini:
 "At over 200 commits, covering almost all supported architectures, this
  was a pretty active cycle for KVM.  Changes include:

   - a lot of s390 changes: optimizations, support for migration, GDB
     support and more

   - ARM changes are pretty small: support for the PSCI 0.2 hypercall
     interface on both the guest and the host (the latter acked by
     Catalin)

   - initial POWER8 and little-endian host support

   - support for running u-boot on embedded POWER targets

   - pretty large changes to MIPS too, completing the userspace
     interface and improving the handling of virtualized timer hardware

   - for x86, a larger set of changes is scheduled for 3.17.  Still, we
     have a few emulator bugfixes and support for running nested
     fully-virtualized Xen guests (para-virtualized Xen guests have
     always worked).  And some optimizations too.

  The only missing architecture here is ia64.  It's not a coincidence
  that support for KVM on ia64 is scheduled for removal in 3.17"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (203 commits)
  KVM: add missing cleanup_srcu_struct
  KVM: PPC: Book3S PR: Rework SLB switching code
  KVM: PPC: Book3S PR: Use SLB entry 0
  KVM: PPC: Book3S HV: Fix machine check delivery to guest
  KVM: PPC: Book3S HV: Work around POWER8 performance monitor bugs
  KVM: PPC: Book3S HV: Make sure we don't miss dirty pages
  KVM: PPC: Book3S HV: Fix dirty map for hugepages
  KVM: PPC: Book3S HV: Put huge-page HPTEs in rmap chain for base address
  KVM: PPC: Book3S HV: Fix check for running inside guest in global_invalidates()
  KVM: PPC: Book3S: Move KVM_REG_PPC_WORT to an unused register number
  KVM: PPC: Book3S: Add ONE_REG register names that were missed
  KVM: PPC: Add CAP to indicate hcall fixes
  KVM: PPC: MPIC: Reset IRQ source private members
  KVM: PPC: Graciously fail broken LE hypercalls
  PPC: ePAPR: Fix hypercall on LE guest
  KVM: PPC: BOOK3S: Remove open coded make_dsisr in alignment handler
  KVM: PPC: BOOK3S: Always use the saved DAR value
  PPC: KVM: Make NX bit available with magic page
  KVM: PPC: Disable NX for old magic page using guests
  KVM: PPC: BOOK3S: HV: Add mixed page-size support for guest
  ...
2014-06-04 08:47:12 -07:00
Nadav Amit 1f85411255 KVM: vmx: DR7 masking on task switch emulation is wrong
The DR7 masking which is done on task switch emulation should be in hex format
(clearing the local breakpoints enable bits 0,2,4 and 6).

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-22 17:47:18 +02:00
Paolo Bonzini ae9fedc793 KVM: x86: get CPL from SS.DPL
CS.RPL is not equal to the CPL in the few instructions between
setting CR0.PE and reloading CS.  And CS.DPL is also not equal
to the CPL for conforming code segments.

However, SS.DPL *is* always equal to the CPL except for the weird
case of SYSRET on AMD processors, which sets SS.DPL=SS.RPL from the
value in the STAR MSR, but force CPL=3 (Intel instead forces
SS.DPL=SS.RPL=CPL=3).

So this patch:

- modifies SVM to update the CPL from SS.DPL rather than CS.RPL;
the above case with SYSRET is not broken further, and the way
to fix it would be to pass the CPL to userspace and back

- modifies VMX to always return the CPL from SS.DPL (except
forcing it to 0 if we are emulating real mode via vm86 mode;
in vm86 mode all DPLs have to be 3, but real mode does allow
privileged instructions).  It also removes the CPL cache,
which becomes a duplicate of the SS access rights cache.

This fixes doing KVM_IOCTL_SET_SREGS exactly after setting
CR0.PE=1 but before CS has been reloaded.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-22 17:47:17 +02:00
Gabriel L. Somlo 87c00572ba kvm: x86: emulate monitor and mwait instructions as nop
Treat monitor and mwait instructions as nop, which is architecturally
correct (but inefficient) behavior. We do this to prevent misbehaving
guests (e.g. OS X <= 10.7) from crashing after they fail to check for
monitor/mwait availability via cpuid.

Since mwait-based idle loops relying on these nop-emulated instructions
would keep the host CPU pegged at 100%, do NOT advertise their presence
via cpuid, to prevent compliant guests from using them inadvertently.

Signed-off-by: Gabriel L. Somlo <somlo@cmu.edu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-08 15:40:49 +02:00
Nadav Amit a4ab9d0cf1 KVM: vmx: handle_dr does not handle RSP correctly
The RSP register is not automatically cached, causing mov DR instruction with
RSP to fail.  Instead the regular register accessing interface should be used.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-07 17:24:59 +02:00
Paolo Bonzini 696dfd95ba KVM: vmx: disable APIC virtualization in nested guests
While running a nested guest, we should disable APIC virtualization
controls (virtualized APIC register accesses, virtual interrupt
delivery and posted interrupts), because we do not expose them to
the nested guest.

Reported-by: Hu Yaohui <loki2441@gmail.com>
Suggested-by: Abel Gordon <abel@stratoscale.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-07 13:46:02 +02:00
Bandan Das 4291b58885 KVM: nVMX: move vmclear and vmptrld pre-checks to nested_vmx_check_vmptr
Some checks are common to all, and moreover,
according to the spec, the check for whether any bits
beyond the physical address width are set are also
applicable to all of them

Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-06 19:00:43 +02:00
Bandan Das 96ec146330 KVM: nVMX: fail on invalid vmclear/vmptrld pointer
The spec mandates that if the vmptrld or vmclear
address is equal to the vmxon region pointer, the
instruction should fail with error "VMPTRLD with
VMXON pointer" or "VMCLEAR with VMXON pointer"

Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-06 19:00:37 +02:00
Bandan Das 3573e22cfe KVM: nVMX: additional checks on vmxon region
Currently, the vmxon region isn't used in the nested case.
However, according to the spec, the vmxon instruction performs
additional sanity checks on this region and the associated
pointer. Modify emulated vmxon to better adhere to the spec
requirements

Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-06 19:00:27 +02:00
Bandan Das 19677e32fe KVM: nVMX: rearrange get_vmx_mem_address
Our common function for vmptr checks (in 2/4) needs to fetch
the memory address

Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-06 18:59:57 +02:00
Bandan Das fe2b201b3b KVM: x86: Check for host supported fields in shadow vmcs
We track shadow vmcs fields through two static lists,
one for read only and another for r/w fields. However, with
addition of new vmcs fields, not all fields may be supported on
all hosts. If so, copy_vmcs12_to_shadow() trying to vmwrite on
unsupported hosts will result in a vmwrite error. For example, commit
36be0b9deb introduced GUEST_BNDCFGS, which is not supported
by all processors. Filter out host unsupported fields before
letting guests use shadow vmcs

Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-04-28 11:14:51 +02:00