Commit d54e4237 authored by Joerg Roedel's avatar Joerg Roedel Committed by Avi Kivity
Browse files

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: default avatarJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 5f3fbc34

arch/x86/kvm/emulate.c

+2 −24
Original line number Original line Diff line number Diff line
@@ -3133,35 +3133,13 @@ static int em_btc(struct x86_emulate_ctxt *ctxt) 




static int em_bsf(struct x86_emulate_ctxt *ctxt)

static int em_bsf(struct x86_emulate_ctxt *ctxt)

{

{

	u8 zf;

	emulate_2op_SrcV_nobyte(ctxt, "bsf");



	__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;

	}

	return X86EMUL_CONTINUE;

	return X86EMUL_CONTINUE;

}

}





static int em_bsr(struct x86_emulate_ctxt *ctxt)

static int em_bsr(struct x86_emulate_ctxt *ctxt)

{

{

	u8 zf;

	emulate_2op_SrcV_nobyte(ctxt, "bsr");



	__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;

	}

	return X86EMUL_CONTINUE;

	return X86EMUL_CONTINUE;

}

}

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