KVM: x86 emulator: Implement jmp far opcode ff/5

Implement jmp far opcode ff/5. It is used by multiboot loader.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 97a740368b30..5b6794adaa2e 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -346,7 +346,8 @@ static u32 group_table[] = {
         [Group5*8] =
         DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM,
         SrcMem | ModRM | Stack, 0,
-        SrcMem | ModRM | Stack, 0, SrcMem | ModRM | Stack, 0,
+        SrcMem | ModRM | Stack, SrcMem | ModRM | Src2Mem16 | ImplicitOps,
+        SrcMem | ModRM | Stack, 0,
         [Group7*8] =
         0, 0, ModRM | SrcMem | Priv, ModRM | SrcMem | Priv,
         SrcNone | ModRM | DstMem | Mov, 0,
@@ -2322,6 +2323,7 @@ special_insn:
         case 0xe9: /* jmp rel */
                 goto jmp;
         case 0xea: /* jmp far */
+        jump_far:
                 if (kvm_load_segment_descriptor(ctxt->vcpu, c->src2.val,
                                                 VCPU_SREG_CS))
                         goto done;
@@ -2397,11 +2399,16 @@ special_insn:
                 ctxt->eflags |= EFLG_DF;
                 c->dst.type = OP_NONE;  /* Disable writeback. */
                 break;
-        case 0xfe ... 0xff:     /* Grp4/Grp5 */
+        case 0xfe: /* Grp4 */
+        grp45:
                 rc = emulate_grp45(ctxt, ops);
                 if (rc != X86EMUL_CONTINUE)
                         goto done;
                 break;
+        case 0xff: /* Grp5 */
+                if (c->modrm_reg == 5)
+                        goto jump_far;
+                goto grp45;
         }
 
 writeback: