Commit 4d763b16 authored by Wanpeng Li's avatar Wanpeng Li Committed by Paolo Bonzini
Browse files

KVM: VMX: check CPUID before allowing read/write of IA32_XSS 



Raise #GP when guest read/write IA32_XSS, but the CPUID bits
say that it shouldn't exist.

Fixes: 20300099 (kvm: vmx: add MSR logic for XSAVES)
Reported-by: default avatarXiaoyao Li <xiaoyao.li@linux.intel.com>
Reported-by: default avatarTao Xu <tao3.xu@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarWanpeng Li <wanpengli@tencent.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent eceb9973

arch/x86/kvm/vmx/vmx.c

+8 −2
Original line number Diff line number Diff line
@@ -1732,7 +1732,10 @@ 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;
@@ -1962,7 +1965,10 @@ 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