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>

2 files changed, 6 insertions, 4 deletions

diff --git a/arch/x86/kvm/kvm_svm.h b/arch/x86/kvm/kvm_svm.h
index ed66e4c078dc..6f275b4cf628 100644
--- a/arch/x86/kvm/kvm_svm.h
+++ b/arch/x86/kvm/kvm_svm.h
@@ -27,6 +27,8 @@ struct vcpu_svm {
         unsigned long vmcb_pa;
         struct svm_cpu_data *svm_data;
         uint64_t asid_generation;
+        uint64_t sysenter_esp;
+        uint64_t sysenter_eip;
 
         u64 next_rip;
 
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 48b22c9892d8..e3e7edca35d1 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -367,8 +367,6 @@ static void svm_vcpu_init_msrpm(u32 *msrpm)
 #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 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 *data)
                 *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 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 data)
                 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: