* [PATCH] KVM: x86 emulator: add bsf/bsr instruction emulation
@ 2010-08-09 10:00 Wei Yongjun
2010-08-10 3:14 ` Avi Kivity
0 siblings, 1 reply; 4+ messages in thread
From: Wei Yongjun @ 2010-08-09 10:00 UTC (permalink / raw)
To: Avi Kivity; +Cc: kvm
Add bsf/bsr instruction emulation (opcode 0x0f 0xbc~0xbd)
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
---
arch/x86/kvm/emulate.c | 28 ++++++++++++++++++++++++++--
1 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index fb4ac8c..831aa6e 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2342,8 +2342,8 @@ 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),
@@ -3464,6 +3464,30 @@ twobyte_insn:
btc: /* btc */
emulate_2op_SrcV_nobyte("btc", c->src, c->dst, ctxt->eflags);
break;
+ case 0xbc: { /* bsf */
+ int zf;
+ __asm__ ("bsf %2, %0; setz %b1"
+ : "=r"(c->dst.val), "=q"(zf)
+ : "r"(c->src.val), "1" (0));
+ ctxt->eflags &= ~X86_EFLAGS_ZF;
+ if (zf) {
+ ctxt->eflags |= X86_EFLAGS_ZF;
+ c->dst.type = OP_NONE; /* Disable writeback. */
+ }
+ break;
+ }
+ case 0xbd: { /* bsr */
+ int zf;
+ __asm__ ("bsr %2, %0; setz %b1"
+ : "=r"(c->dst.val), "=q"(zf)
+ : "r"(c->src.val), "1" (0));
+ 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 :
--
1.7.0.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] KVM: x86 emulator: add bsf/bsr instruction emulation
2010-08-09 10:00 [PATCH] KVM: x86 emulator: add bsf/bsr instruction emulation Wei Yongjun
@ 2010-08-10 3:14 ` Avi Kivity
2010-08-10 5:48 ` [PATCH v2] " Wei Yongjun
0 siblings, 1 reply; 4+ messages in thread
From: Avi Kivity @ 2010-08-10 3:14 UTC (permalink / raw)
To: Wei Yongjun; +Cc: kvm
On 08/09/2010 06:00 AM, Wei Yongjun wrote:
> Add bsf/bsr instruction emulation (opcode 0x0f 0xbc~0xbd)
>
> @@ -3464,6 +3464,30 @@ twobyte_insn:
> btc: /* btc */
> emulate_2op_SrcV_nobyte("btc", c->src, c->dst, ctxt->eflags);
> break;
> + case 0xbc: { /* bsf */
> + int zf;
> + __asm__ ("bsf %2, %0; setz %b1"
> + : "=r"(c->dst.val), "=q"(zf)
> + : "r"(c->src.val), "1" (0));
Won't the high bytes of zf remain clear? Please examine the assembly.
Declaring it u8 is probably better.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v2] KVM: x86 emulator: add bsf/bsr instruction emulation
2010-08-10 3:14 ` Avi Kivity
@ 2010-08-10 5:48 ` Wei Yongjun
2010-08-10 10:21 ` Avi Kivity
0 siblings, 1 reply; 4+ messages in thread
From: Wei Yongjun @ 2010-08-10 5:48 UTC (permalink / raw)
To: Avi Kivity; +Cc: kvm
Add bsf/bsr instruction emulation (opcode 0x0f 0xbc~0xbd)
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
---
v1 -> v2: use 'u8 zf' instead of int.
---
arch/x86/kvm/emulate.c | 28 ++++++++++++++++++++++++++--
1 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 66139ad..7cbcb66 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2381,8 +2381,8 @@ 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),
@@ -3500,6 +3500,30 @@ 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 :
--
1.7.0.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] KVM: x86 emulator: add bsf/bsr instruction emulation
2010-08-10 5:48 ` [PATCH v2] " Wei Yongjun
@ 2010-08-10 10:21 ` Avi Kivity
0 siblings, 0 replies; 4+ messages in thread
From: Avi Kivity @ 2010-08-10 10:21 UTC (permalink / raw)
To: Wei Yongjun; +Cc: kvm
On 08/10/2010 01:48 AM, Wei Yongjun wrote:
> Add bsf/bsr instruction emulation (opcode 0x0f 0xbc~0xbd)
>
Applied, thanks.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2010-08-10 10:21 UTC | newest]
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2010-08-09 10:00 [PATCH] KVM: x86 emulator: add bsf/bsr instruction emulation Wei Yongjun
2010-08-10 3:14 ` Avi Kivity
2010-08-10 5:48 ` [PATCH v2] " Wei Yongjun
2010-08-10 10:21 ` Avi Kivity
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