On Thu, Nov 24, 2022, Yang Weijiang wrote: > From: Paolo Bonzini <pbonzini@xxxxxxxxxx> > > Refine the code path of the existing clearing of supported_xss in this way: > initialize the supported_xss with the filter of KVM_SUPPORTED_XSS mask and > update its value in a bit clear manner (rather than bit setting). > > Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx> > Signed-off-by: Like Xu <like.xu@xxxxxxxxxxxxxxx> > Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> > Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx> > --- > arch/x86/kvm/vmx/vmx.c | 5 +++-- > arch/x86/kvm/x86.c | 6 +++++- > 2 files changed, 8 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index 9bd52ad3bbf4..2ab4c33b5008 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -7738,9 +7738,10 @@ static __init void vmx_set_cpu_caps(void) > kvm_cpu_cap_set(X86_FEATURE_UMIP); > > /* CPUID 0xD.1 */ > - kvm_caps.supported_xss = 0; This needs to stay until VMX actually supports something. > - if (!cpu_has_vmx_xsaves()) > + if (!cpu_has_vmx_xsaves()) { > kvm_cpu_cap_clear(X86_FEATURE_XSAVES); > + kvm_caps.supported_xss = 0; This is already handled in common KVM. > + } > > /* CPUID 0x80000001 and 0x7 (RDPID) */ > if (!cpu_has_vmx_rdtscp()) { > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 74c858eaa1ea..889be0c9176d 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -217,6 +217,8 @@ static struct kvm_user_return_msrs __percpu *user_return_msrs; > | XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \ > | XFEATURE_MASK_PKRU | XFEATURE_MASK_XTILE) > > +#define KVM_SUPPORTED_XSS 0 > + > u64 __read_mostly host_efer; > EXPORT_SYMBOL_GPL(host_efer); > > @@ -11999,8 +12001,10 @@ int kvm_arch_hardware_setup(void *opaque) > > rdmsrl_safe(MSR_EFER, &host_efer); > > - if (boot_cpu_has(X86_FEATURE_XSAVES)) > + if (boot_cpu_has(X86_FEATURE_XSAVES)) { > rdmsrl(MSR_IA32_XSS, host_xss); > + kvm_caps.supported_xss = host_xss & KVM_SUPPORTED_XSS; > + } > > kvm_init_pmu_capability(); > > -- > 2.27.0 >