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, 5 insertions, 4 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index de00b6026b76..6268f6ce6434 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -634,13 +634,13 @@ enum emulation_result {
 #define EMULTYPE_NO_DECODE          (1 << 0)
 #define EMULTYPE_TRAP_UD            (1 << 1)
 #define EMULTYPE_SKIP               (1 << 2)
-int x86_emulate_instruction(struct kvm_vcpu *vcpu,
-                        unsigned long cr2, int emulation_type);
+int x86_emulate_instruction(struct kvm_vcpu *vcpu, unsigned long cr2,
+                            int emulation_type, void *insn, int insn_len);
 
 static inline int emulate_instruction(struct kvm_vcpu *vcpu,
                         int emulation_type)
 {
-        return x86_emulate_instruction(vcpu, 0, emulation_type);
+        return x86_emulate_instruction(vcpu, 0, emulation_type, NULL, 0);
 }
 
 void realmode_lgdt(struct kvm_vcpu *vcpu, u16 size, unsigned long address);
@@ -721,7 +721,8 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu);
 
 int kvm_fix_hypercall(struct kvm_vcpu *vcpu);
 
-int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t gva, u32 error_code);
+int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t gva, u32 error_code,
+                       void *insn, int insn_len);
 void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva);
 
 void kvm_enable_tdp(void);