[ Upstream commit 4d763b168e9c5c366b05812c7bba7662e5ea3669 ] Raise #GP when guest read/write IA32_XSS, but the CPUID bits say that it shouldn't exist. Fixes: 203000993de5 (kvm: vmx: add MSR logic for XSAVES) Reported-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxxxxxxxx> Reported-by: Tao Xu <tao3.xu@xxxxxxxxx> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/x86/kvm/vmx.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 82253d31842a2..2938b4bcc9684 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -4135,7 +4135,10 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) return vmx_get_vmx_msr(&vmx->nested.msrs, msr_info->index, &msr_info->data); case MSR_IA32_XSS: - if (!vmx_xsaves_supported()) + if (!vmx_xsaves_supported() || + (!msr_info->host_initiated && + !(guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) && + guest_cpuid_has(vcpu, X86_FEATURE_XSAVES)))) return 1; msr_info->data = vcpu->arch.ia32_xss; break; @@ -4302,7 +4305,10 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) return 1; return vmx_set_vmx_msr(vcpu, msr_index, data); case MSR_IA32_XSS: - if (!vmx_xsaves_supported()) + if (!vmx_xsaves_supported() || + (!msr_info->host_initiated && + !(guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) && + guest_cpuid_has(vcpu, X86_FEATURE_XSAVES)))) return 1; /* * The only supported bit as of Skylake is bit 8, but -- 2.20.1
