[PATCH v2 5/8] KVM: x86: nSVM: Save gPAT to vmcb12.g_pat on VMEXIT

[Jim Mattson <jmattson@google.com>]

According to the APM volume 3 pseudo-code for "VMRUN," when nested paging
is enabled in the vmcb, the guest PAT register (gPAT) is saved to the vmcb
on emulated VMEXIT.

Under KVM, the guest PAT register lives in the vmcb02 g_pat field. Save
this value to the vmcb12 g_pat field on emulated VMEXIT.

Fixes: 15038e147247 ("KVM: SVM: obey guest PAT")
Signed-off-by: Jim Mattson <jmattson@google.com>
---
 arch/x86/kvm/svm/nested.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index b0c0184e6e24..5fb31faf2b46 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -1189,6 +1189,9 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
 	vmcb12->save.dr6    = svm->vcpu.arch.dr6;
 	vmcb12->save.cpl    = vmcb02->save.cpl;
 
+	if (nested_npt_enabled(svm))
+		vmcb12->save.g_pat = svm->vmcb->save.g_pat;
+
 	if (guest_cpu_cap_has(vcpu, X86_FEATURE_SHSTK)) {
 		vmcb12->save.s_cet	= vmcb02->save.s_cet;
 		vmcb12->save.isst_addr	= vmcb02->save.isst_addr;
-- 
2.52.0.457.g6b5491de43-goog