KVM: SVM: use explicit 64bit storage for sysenter values

Since AMD does not support sysenter in 64bit mode, the VMCB fields storing
the MSRs are truncated to 32bit upon VMRUN/#VMEXIT. So store the values
in a separate 64bit storage to avoid truncation.

[andre: fix amd->amd migration]

Signed-off-by: Christoph Egger <christoph.egger@amd.com>
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 48b22c9..e3e7edc 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -367,8 +367,6 @@
 #endif
 	set_msr_interception(msrpm, MSR_K6_STAR, 1, 1);
 	set_msr_interception(msrpm, MSR_IA32_SYSENTER_CS, 1, 1);
-	set_msr_interception(msrpm, MSR_IA32_SYSENTER_ESP, 1, 1);
-	set_msr_interception(msrpm, MSR_IA32_SYSENTER_EIP, 1, 1);
 }
 
 static void svm_enable_lbrv(struct vcpu_svm *svm)
@@ -1981,10 +1979,10 @@
 		*data = svm->vmcb->save.sysenter_cs;
 		break;
 	case MSR_IA32_SYSENTER_EIP:
-		*data = svm->vmcb->save.sysenter_eip;
+		*data = svm->sysenter_eip;
 		break;
 	case MSR_IA32_SYSENTER_ESP:
-		*data = svm->vmcb->save.sysenter_esp;
+		*data = svm->sysenter_esp;
 		break;
 	/* Nobody will change the following 5 values in the VMCB so
 	   we can safely return them on rdmsr. They will always be 0
@@ -2071,9 +2069,11 @@
 		svm->vmcb->save.sysenter_cs = data;
 		break;
 	case MSR_IA32_SYSENTER_EIP:
+		svm->sysenter_eip = data;
 		svm->vmcb->save.sysenter_eip = data;
 		break;
 	case MSR_IA32_SYSENTER_ESP:
+		svm->sysenter_esp = data;
 		svm->vmcb->save.sysenter_esp = data;
 		break;
 	case MSR_IA32_DEBUGCTLMSR: