From f4905184931ec1664184f941215d04ebf29315f4 Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Thu, 20 Jun 2019 17:00:02 +0800 Subject: KVM: VMX: check CPUID before allowing read/write of IA32_XSS MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 4d763b168e9c5c366b05812c7bba7662e5ea3669 upstream. 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 Reported-by: Tao Xu Cc: Paolo Bonzini Cc: Radim Krčmář Cc: stable@vger.kernel.org Signed-off-by: Wanpeng Li Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/vmx/vmx.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 1f976f35db06..d9ea86cc899f 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1718,7 +1718,10 @@ 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; @@ -1929,7 +1932,10 @@ 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 -- cgit v1.2.3