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| author | Kyle Huey <me@kylehuey.com> | 2017-03-20 01:16:28 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-04-21 12:50:06 +0200 |
| commit | db2336a80489e7c3c7728cefd9be58fac5ecfb39 (patch) | |
| tree | 2a462ecee35d68dea1b931ba5ee226933e663cd0 /arch/x86/kvm/emulate.c | |
| parent | bd17117bb2af60d4bc44e0f9c859e800a3d99722 (diff) | |
| download | linux-db2336a80489e7c3c7728cefd9be58fac5ecfb39.tar.bz2 | |
KVM: x86: virtualize cpuid faulting
Hardware support for faulting on the cpuid instruction is not required to
emulate it, because cpuid triggers a VM exit anyways. KVM handles the relevant
MSRs (MSR_PLATFORM_INFO and MSR_MISC_FEATURES_ENABLE) and upon a
cpuid-induced VM exit checks the cpuid faulting state and the CPL.
kvm_require_cpl is even kind enough to inject the GP fault for us.
Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Reviewed-by: David Matlack <dmatlack@google.com>
[Return "1" from kvm_emulate_cpuid, it's not void. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/emulate.c')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 45c7306c8780..6a2ea945d01f 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3854,6 +3854,13 @@ static int em_sti(struct x86_emulate_ctxt *ctxt) static int em_cpuid(struct x86_emulate_ctxt *ctxt) { u32 eax, ebx, ecx, edx; + u64 msr = 0; + + ctxt->ops->get_msr(ctxt, MSR_MISC_FEATURES_ENABLES, &msr); + if (msr & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT && + ctxt->ops->cpl(ctxt)) { + return emulate_gp(ctxt, 0); + } eax = reg_read(ctxt, VCPU_REGS_RAX); ecx = reg_read(ctxt, VCPU_REGS_RCX); |