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>

1 files changed, 3 insertions, 2 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 01c5a104031f..ea6063d9242e 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3330,7 +3330,8 @@ void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
         }
 }
 
-int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
+int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code,
+                       void *insn, int insn_len)
 {
         int r;
         enum emulation_result er;
@@ -3348,7 +3349,7 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
         if (r)
                 goto out;
 
-        er = x86_emulate_instruction(vcpu, cr2, 0);
+        er = x86_emulate_instruction(vcpu, cr2, 0, insn, insn_len);
 
         switch (er) {
         case EMULATE_DONE: