Commit d9574a25 authored by Wei Yongjun's avatar Wei Yongjun Committed by Avi Kivity

KVM: x86 emulator: add bsf/bsr instruction emulation

Add bsf/bsr instruction emulation (opcode 0x0f 0xbc~0xbd)
Signed-off-by: default avatarWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 8c5eee30
......@@ -2379,8 +2379,8 @@ static struct opcode twobyte_table[256] = {
/* 0xB8 - 0xBF */
N, N,
G(BitOp, group8), D(DstMem | SrcReg | ModRM | BitOp | Lock),
N, N, D(ByteOp | DstReg | SrcMem | ModRM | Mov),
D(DstReg | SrcMem16 | ModRM | Mov),
D(DstReg | SrcMem | ModRM), D(DstReg | SrcMem | ModRM),
D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
/* 0xC0 - 0xCF */
N, N, N, D(DstMem | SrcReg | ModRM | Mov),
N, N, N, GD(0, &group9),
......@@ -3511,6 +3511,30 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
btc: /* btc */
emulate_2op_SrcV_nobyte("btc", c->src, c->dst, ctxt->eflags);
break;
case 0xbc: { /* bsf */
u8 zf;
__asm__ ("bsf %2, %0; setz %1"
: "=r"(c->dst.val), "=q"(zf)
: "r"(c->src.val));
ctxt->eflags &= ~X86_EFLAGS_ZF;
if (zf) {
ctxt->eflags |= X86_EFLAGS_ZF;
c->dst.type = OP_NONE; /* Disable writeback. */
}
break;
}
case 0xbd: { /* bsr */
u8 zf;
__asm__ ("bsr %2, %0; setz %1"
: "=r"(c->dst.val), "=q"(zf)
: "r"(c->src.val));
ctxt->eflags &= ~X86_EFLAGS_ZF;
if (zf) {
ctxt->eflags |= X86_EFLAGS_ZF;
c->dst.type = OP_NONE; /* Disable writeback. */
}
break;
}
case 0xbe ... 0xbf: /* movsx */
c->dst.bytes = c->op_bytes;
c->dst.val = (c->d & ByteOp) ? (s8) c->src.val :
......
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