From d9574a25afc3cd7ccd6a0bc05252bb84189e4021 Mon Sep 17 00:00:00 2001 From: Wei Yongjun Date: Tue, 10 Aug 2010 13:48:22 +0800 Subject: [PATCH] KVM: x86 emulator: add bsf/bsr instruction emulation Add bsf/bsr instruction emulation (opcode 0x0f 0xbc~0xbd) Signed-off-by: Wei Yongjun Signed-off-by: Avi Kivity --- arch/x86/kvm/emulate.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 8617c344405d..f6b124fcc3fd 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -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 @@ twobyte_insn: 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 : -- 2.20.1