KVM: SVM: Sync g_pat with guest-written PAT value

When hardware supports the g_pat VMCB field, we can use it for emulating
the PAT configuration that the guest configures by writing to the
corresponding MSR.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Tested-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 414ec25b673e0ad745a30bcc7250bebfdad5e979..d36cfaf5a97a7e90e9144aa2f0de7cbdca8c9a05 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3350,6 +3350,16 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
        case MSR_VM_IGNNE:
                vcpu_unimpl(vcpu, "unimplemented wrmsr: 0x%x data 0x%llx\n", ecx, data);
                break;
+       case MSR_IA32_CR_PAT:
+               if (npt_enabled) {
+                       if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data))
+                               return 1;
+                       vcpu->arch.pat = data;
+                       svm_set_guest_pat(svm, &svm->vmcb->save.g_pat);
+                       mark_dirty(svm->vmcb, VMCB_NPT);
+                       break;
+               }
+               /* fall through */
        default:
                return kvm_set_msr_common(vcpu, msr);
        }