KVM: SVM: Add support for SVM instruction address check change

New AMD CPUs have a change that checks #VMEXIT intercept on special SVM
instructions before checking their EAX against reserved memory region.
This change is indicated by CPUID_0x8000000A_EDX[28]. If it is 1, #VMEXIT
is triggered before #GP. KVM doesn't need to intercept and emulate #GP
faults as #GP is supposed to be triggered.

Co-developed-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Wei Huang <wei.huang2@amd.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210126081831.570253-4-wei.huang2@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 073a364..0378d42 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1040,6 +1040,9 @@ static __init int svm_hardware_setup(void)
 		}
 	}
 
+	if (boot_cpu_has(X86_FEATURE_SVME_ADDR_CHK))
+		svm_gp_erratum_intercept = false;
+
 	if (vgif) {
 		if (!boot_cpu_has(X86_FEATURE_VGIF))
 			vgif = false;