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: Yang Weijiang <weijiang.yang@xxxxxxxxx>
Message-Id: <20220517154100.29983-10-weijiang.yang@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
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 77bad663d804..32e41bd217e3 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7717,9 +7717,10 @@ static __init void vmx_set_cpu_caps(void)
kvm_cpu_cap_set(X86_FEATURE_UMIP);
/* CPUID 0xD.1 */
- kvm_caps.supported_xss = 0;
- if (!cpu_has_vmx_xsaves())
+ if (!cpu_has_vmx_xsaves()) {
kvm_cpu_cap_clear(X86_FEATURE_XSAVES);
+ kvm_caps.supported_xss = 0;
+ }
/* 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 b3d2a7ad1d18..19cb5840300b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -213,6 +213,8 @@ 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);
@@ -11965,8 +11967,10 @@ 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
