From d54e4237bcbb400fda11c902fd538aa0b4805720 Mon Sep 17 00:00:00 2001
From: Joerg Roedel <joerg.roedel@amd.com>
Date: Mon, 7 May 2012 12:12:25 +0200
Subject: [PATCH] KVM: x86 emulator: convert bsf/bsr instructions to
emulate_2op_SrcV_nobyte()
The instruction emulation for bsrw is broken in KVM because
the code always uses bsr with 32 or 64 bit operand size for
emulation. Fix that by using emulate_2op_SrcV_nobyte() macro
to use guest operand size for emulation.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/emulate.c | 26 ++------------------------
1 file changed, 2 insertions(+), 24 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 7fd25763b0e0..f95d242ee9f7 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3133,35 +3133,13 @@ static int em_btc(struct x86_emulate_ctxt *ctxt)
static int em_bsf(struct x86_emulate_ctxt *ctxt)
{
- u8 zf;
-
- __asm__ ("bsf %2, %0; setz %1"
- : "=r"(ctxt->dst.val), "=q"(zf)
- : "r"(ctxt->src.val));
-
- ctxt->eflags &= ~X86_EFLAGS_ZF;
- if (zf) {
- ctxt->eflags |= X86_EFLAGS_ZF;
- /* Disable writeback. */
- ctxt->dst.type = OP_NONE;
- }
+ emulate_2op_SrcV_nobyte(ctxt, "bsf");
return X86EMUL_CONTINUE;
}
static int em_bsr(struct x86_emulate_ctxt *ctxt)
{
- u8 zf;
-
- __asm__ ("bsr %2, %0; setz %1"
- : "=r"(ctxt->dst.val), "=q"(zf)
- : "r"(ctxt->src.val));
-
- ctxt->eflags &= ~X86_EFLAGS_ZF;
- if (zf) {
- ctxt->eflags |= X86_EFLAGS_ZF;
- /* Disable writeback. */
- ctxt->dst.type = OP_NONE;
- }
+ emulate_2op_SrcV_nobyte(ctxt, "bsr");
return X86EMUL_CONTINUE;
}