| Message ID | 20200508233749.3417-1-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: Restore update of required xstate size in guest's CPUID | expand |
On 5/9/2020 7:37 AM, Sean Christopherson wrote: > Restore a guest CPUID update that was unintentional collateral damage > when the per-vCPU guest_xstate_size field was removed. It's really unintentional. None of us noticed it. :( It's good that you catch it! > Cc: Xiaoyao Li <xiaoyao.li@intel.com> > Fixes: d87277414b851 ("kvm: x86: Cleanup vcpu->arch.guest_xstate_size") > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > > There's nothing more thrilling than watching bisect home in on your own > commits, only to land on someone else's on the very last step. > > arch/x86/kvm/cpuid.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index 35845704cf57a..cd708b0b460a0 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -84,11 +84,13 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu) > kvm_read_cr4_bits(vcpu, X86_CR4_PKE)); > > best = kvm_find_cpuid_entry(vcpu, 0xD, 0); > - if (!best) > + if (!best) { > vcpu->arch.guest_supported_xcr0 = 0; > - else > + } else { > vcpu->arch.guest_supported_xcr0 = > (best->eax | ((u64)best->edx << 32)) & supported_xcr0; > + best->ebx = xstate_required_size(vcpu->arch.xcr0, false); > + } > > best = kvm_find_cpuid_entry(vcpu, 0xD, 1); > if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) || >
On 09/05/20 01:37, Sean Christopherson wrote: > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index 35845704cf57a..cd708b0b460a0 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -84,11 +84,13 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu) > kvm_read_cr4_bits(vcpu, X86_CR4_PKE)); > > best = kvm_find_cpuid_entry(vcpu, 0xD, 0); > - if (!best) > + if (!best) { > vcpu->arch.guest_supported_xcr0 = 0; > - else > + } else { > vcpu->arch.guest_supported_xcr0 = > (best->eax | ((u64)best->edx << 32)) & supported_xcr0; > + best->ebx = xstate_required_size(vcpu->arch.xcr0, false); > + } > > best = kvm_find_cpuid_entry(vcpu, 0xD, 1); > if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) || > -- 2.26.0 Ugh, I'll write a testcase as penance. Squashed, thanks. Paolo
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 35845704cf57a..cd708b0b460a0 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -84,11 +84,13 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu) kvm_read_cr4_bits(vcpu, X86_CR4_PKE)); best = kvm_find_cpuid_entry(vcpu, 0xD, 0); - if (!best) + if (!best) { vcpu->arch.guest_supported_xcr0 = 0; - else + } else { vcpu->arch.guest_supported_xcr0 = (best->eax | ((u64)best->edx << 32)) & supported_xcr0; + best->ebx = xstate_required_size(vcpu->arch.xcr0, false); + } best = kvm_find_cpuid_entry(vcpu, 0xD, 1); if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
Restore a guest CPUID update that was unintentional collateral damage when the per-vCPU guest_xstate_size field was removed. Cc: Xiaoyao Li <xiaoyao.li@intel.com> Fixes: d87277414b851 ("kvm: x86: Cleanup vcpu->arch.guest_xstate_size") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- There's nothing more thrilling than watching bisect home in on your own commits, only to land on someone else's on the very last step. arch/x86/kvm/cpuid.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)