KVM: x86 emulator: Add vmmcall/vmcall to x86_emulate (v3)

Add vmmcall/vmcall to x86_emulate.  Future patch will implement functionality
for these instructions.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 17 insertions, 6 deletions

diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index bd46de6bf891..84af9cc737fa 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -1380,6 +1380,12 @@ twobyte_insn:
                         u16 size;
                         unsigned long address;
 
+                case 0: /* vmcall */
+                        if (modrm_mod != 3 || modrm_rm != 1)
+                                goto cannot_emulate;
+
+                        /* nop */
+                        break;
                 case 2: /* lgdt */
                         rc = read_descriptor(ctxt, ops, src.ptr,
                                              &size, &address, op_bytes);
@@ -1387,12 +1393,17 @@ twobyte_insn:
                                 goto done;
                         realmode_lgdt(ctxt->vcpu, size, address);
                         break;
-                case 3: /* lidt */
-                        rc = read_descriptor(ctxt, ops, src.ptr,
-                                             &size, &address, op_bytes);
-                        if (rc)
-                                goto done;
-                        realmode_lidt(ctxt->vcpu, size, address);
+                case 3: /* lidt/vmmcall */
+                        if (modrm_mod == 3 && modrm_rm == 1) {
+                                /* nop */
+                        } else {
+                                rc = read_descriptor(ctxt, ops, src.ptr,
+                                                     &size, &address,
+                                                     op_bytes);
+                                if (rc)
+                                        goto done;
+                                realmode_lidt(ctxt->vcpu, size, address);
+                        }
                         break;
                 case 4: /* smsw */
                         if (modrm_mod != 3)