| Message ID | 20230421134615.62539-8-weijiang.yang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Enable CET Virtualization | expand |
On 4/21/2023 9:46 PM, Yang Weijiang wrote: > Update CPUID(EAX=0DH,ECX=1) when the guest's XSS is modified. > CPUID(EAX=0DH,ECX=1).EBX reports current required storage size for all > features enabled via XCR0 | XSS so that guest can allocate correct xsave > buffer. > > Note, KVM does not yet support any XSS based features, i.e. supported_xss > is guaranteed to be zero at this time. > > Co-developed-by: Zhang Yi Z <yi.z.zhang@linux.intel.com> > Signed-off-by: Zhang Yi Z <yi.z.zhang@linux.intel.com> > Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> > --- > arch/x86/kvm/cpuid.c | 11 ++++++++--- > arch/x86/kvm/x86.c | 6 ++++-- > 2 files changed, 12 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index 123bf8b97a4b..dd6d5150d86a 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -276,9 +276,14 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e > best->ebx = xstate_required_size(vcpu->arch.xcr0, false); > > best = cpuid_entry2_find(entries, nent, 0xD, 1); > - if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) || > - cpuid_entry_has(best, X86_FEATURE_XSAVEC))) > - best->ebx = xstate_required_size(vcpu->arch.xcr0, true); > + if (best) { > + if (cpuid_entry_has(best, X86_FEATURE_XSAVES) || > + cpuid_entry_has(best, X86_FEATURE_XSAVEC)) { Is it necessary to change to use two ifs? > + u64 xstate = vcpu->arch.xcr0 | vcpu->arch.ia32_xss; > + > + best->ebx = xstate_required_size(xstate, true); > + } > + } > > best = __kvm_find_kvm_cpuid_features(vcpu, entries, nent); > if (kvm_hlt_in_guest(vcpu->kvm) && best && > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 33a780fe820b..ab3360a10933 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -3776,8 +3776,10 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) > */ > if (data & ~kvm_caps.supported_xss) > return 1; > - vcpu->arch.ia32_xss = data; > - kvm_update_cpuid_runtime(vcpu); > + if (vcpu->arch.ia32_xss != data) { > + vcpu->arch.ia32_xss = data; > + kvm_update_cpuid_runtime(vcpu); > + } > break; > case MSR_SMI_COUNT: > if (!msr_info->host_initiated)
On 4/24/2023 9:38 AM, Binbin Wu wrote: > > On 4/21/2023 9:46 PM, Yang Weijiang wrote: >> [...] >> @@ -276,9 +276,14 @@ static void __kvm_update_cpuid_runtime(struct >> kvm_vcpu *vcpu, struct kvm_cpuid_e >> best->ebx = xstate_required_size(vcpu->arch.xcr0, false); >> best = cpuid_entry2_find(entries, nent, 0xD, 1); >> - if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) || >> - cpuid_entry_has(best, X86_FEATURE_XSAVEC))) >> - best->ebx = xstate_required_size(vcpu->arch.xcr0, true); >> + if (best) { >> + if (cpuid_entry_has(best, X86_FEATURE_XSAVES) || >> + cpuid_entry_has(best, X86_FEATURE_XSAVEC)) { > > Is it necessary to change to use two ifs? Good catch! I changed the patch a bit, but forgot to re-shape it. > > >> + u64 xstate = vcpu->arch.xcr0 | vcpu->arch.ia32_xss; >> + >> + best->ebx = xstate_required_size(xstate, true); >> [...]
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 123bf8b97a4b..dd6d5150d86a 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -276,9 +276,14 @@ static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_e best->ebx = xstate_required_size(vcpu->arch.xcr0, false); best = cpuid_entry2_find(entries, nent, 0xD, 1); - if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) || - cpuid_entry_has(best, X86_FEATURE_XSAVEC))) - best->ebx = xstate_required_size(vcpu->arch.xcr0, true); + if (best) { + if (cpuid_entry_has(best, X86_FEATURE_XSAVES) || + cpuid_entry_has(best, X86_FEATURE_XSAVEC)) { + u64 xstate = vcpu->arch.xcr0 | vcpu->arch.ia32_xss; + + best->ebx = xstate_required_size(xstate, true); + } + } best = __kvm_find_kvm_cpuid_features(vcpu, entries, nent); if (kvm_hlt_in_guest(vcpu->kvm) && best && diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 33a780fe820b..ab3360a10933 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3776,8 +3776,10 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) */ if (data & ~kvm_caps.supported_xss) return 1; - vcpu->arch.ia32_xss = data; - kvm_update_cpuid_runtime(vcpu); + if (vcpu->arch.ia32_xss != data) { + vcpu->arch.ia32_xss = data; + kvm_update_cpuid_runtime(vcpu); + } break; case MSR_SMI_COUNT: if (!msr_info->host_initiated)