From e8b6fa70e3545f0afd63434dbd0c5220d47205f6 Mon Sep 17 00:00:00 2001 From: Wei Yongjun Date: Wed, 18 Aug 2010 16:43:13 +0800 Subject: [PATCH] KVM: x86 emulator: add CBW/CWDE/CDQE instruction emulation Add CBW/CWDE/CDQE instruction emulation.(opcode 0x98) Used by FreeBSD's boot loader. Signed-off-by: Wei Yongjun Signed-off-by: Avi Kivity --- arch/x86/kvm/emulate.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index aab62d50752e..312dda57f93b 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2300,7 +2300,7 @@ static struct opcode opcode_table[256] = { /* 0x90 - 0x97 */ X8(D(SrcAcc | DstReg)), /* 0x98 - 0x9F */ - N, N, D(SrcImmFAddr | No64), N, + D(DstAcc | SrcNone), N, D(SrcImmFAddr | No64), N, D(ImplicitOps | Stack), D(ImplicitOps | Stack), N, N, /* 0xA0 - 0xA7 */ D(ByteOp | DstAcc | SrcMem | Mov | MemAbs), D(DstAcc | SrcMem | Mov | MemAbs), @@ -3003,6 +3003,13 @@ special_insn: if (c->dst.addr.reg == &c->regs[VCPU_REGS_RAX]) break; goto xchg; + case 0x98: /* cbw/cwde/cdqe */ + switch (c->op_bytes) { + case 2: c->dst.val = (s8)c->dst.val; break; + case 4: c->dst.val = (s16)c->dst.val; break; + case 8: c->dst.val = (s32)c->dst.val; break; + } + break; case 0x9c: /* pushf */ c->src.val = (unsigned long) ctxt->eflags; emulate_push(ctxt, ops);