KVM: x86 emulator: add JrCXZ instruction emulation

Add JrCXZ instruction emulation (opcode 0xe3)
Used by FreeBSD boot loader.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index aece501edce4..312e798d5425 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2487,7 +2487,7 @@ static struct opcode opcode_table[256] = {
         /* 0xD8 - 0xDF */
         N, N, N, N, N, N, N, N,
         /* 0xE0 - 0xE7 */
-        X3(D(SrcImmByte)), N,
+        X4(D(SrcImmByte)),
         D(ByteOp | SrcImmUByte | DstAcc), D(SrcImmUByte | DstAcc),
         D(ByteOp | SrcAcc | DstImmUByte), D(SrcAcc | DstImmUByte),
         /* 0xE8 - 0xEF */
@@ -3285,6 +3285,10 @@ special_insn:
                     (c->b == 0xe2 || test_cc(c->b ^ 0x5, ctxt->eflags)))
                         jmp_rel(c, c->src.val);
                 break;
+        case 0xe3:      /* jcxz/jecxz/jrcxz */
+                if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0)
+                        jmp_rel(c, c->src.val);
+                break;
         case 0xe4:      /* inb */
         case 0xe5:      /* in */
                 goto do_io_in;