From: Like Xu <like.xu@xxxxxxxxxxxxxxx> On processors supporting XSAVES and XRSTORS, Architectural LBR XSAVE support is enumerated from CPUID.(EAX=0DH, ECX=1):ECX[bit 15]. The detailed sub-leaf for Arch LBR is enumerated in CPUID.(0DH, 0FH). XSAVES provides a faster means than RDMSR for guest to read all LBRs. When guest IA32_XSS[bit 15] is set, the Arch LBR state can be saved using XSAVES and restored by XRSTORS with the appropriate RFBM. Signed-off-by: Like Xu <like.xu@xxxxxxxxxxxxxxx> Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx> --- arch/x86/kvm/vmx/vmx.c | 4 ++++ arch/x86/kvm/x86.c | 2 +- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 7238628acb90..1b7194b9b6bc 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7546,6 +7546,10 @@ static __init void vmx_set_cpu_caps(void) kvm_cpu_cap_check_and_set(X86_FEATURE_DS); kvm_cpu_cap_check_and_set(X86_FEATURE_DTES64); } + if (!cpu_has_vmx_arch_lbr()) { + kvm_cpu_cap_clear(X86_FEATURE_ARCH_LBR); + supported_xss &= ~XFEATURE_MASK_LBR; + } if (!enable_sgx) { kvm_cpu_cap_clear(X86_FEATURE_SGX); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 90b3129a2fbe..637ecd19c646 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -224,7 +224,7 @@ 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 +#define KVM_SUPPORTED_XSS XFEATURE_MASK_LBR u64 __read_mostly host_efer; EXPORT_SYMBOL_GPL(host_efer); -- 2.27.0