From: Like Xu <like.xu@xxxxxxxxxxxxxxx>
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>
---
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 c15be89d6619..f4d228a905c8 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7244,9 +7244,10 @@ static __init void vmx_set_cpu_caps(void)
kvm_cpu_cap_set(X86_FEATURE_UMIP);
/* CPUID 0xD.1 */
- supported_xss = 0;
- if (!cpu_has_vmx_xsaves())
+ if (!cpu_has_vmx_xsaves()) {
kvm_cpu_cap_clear(X86_FEATURE_XSAVES);
+ 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 2ebb05212652..ef80370d825b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -210,6 +210,8 @@ static struct kvm_user_return_msrs __percpu *user_return_msrs;
| XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \
| XFEATURE_MASK_PKRU)
+#define KVM_SUPPORTED_XSS 0
+
u64 __read_mostly host_efer;
EXPORT_SYMBOL_GPL(host_efer);
@@ -11002,8 +11004,10 @@ 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);
+ supported_xss = host_xss & KVM_SUPPORTED_XSS;
+ }
r = ops->hardware_setup();
if (r != 0)
--
2.25.1
