KVM: SVM: copy instruction bytes from VMCB

In case of a nested page fault or an intercepted #PF newer SVM
implementations provide a copy of the faulting instruction bytes
in the VMCB.
Use these bytes to feed the instruction emulator and avoid the costly
guest instruction fetch in this case.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index a04c01e..af4b911 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1527,7 +1527,9 @@
 		trace_kvm_page_fault(fault_address, error_code);
 		if (!npt_enabled && kvm_event_needs_reinjection(&svm->vcpu))
 			kvm_mmu_unprotect_page_virt(&svm->vcpu, fault_address);
-		r = kvm_mmu_page_fault(&svm->vcpu, fault_address, error_code);
+		r = kvm_mmu_page_fault(&svm->vcpu, fault_address, error_code,
+			svm->vmcb->control.insn_bytes,
+			svm->vmcb->control.insn_len);
 		break;
 	case KVM_PV_REASON_PAGE_NOT_PRESENT:
 		svm->apf_reason = 0;