From: Aurelien Jarno <aurelien-rXXEIb44qovR7s880joybQ@public.gmane.org>
To: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Subject: Re: [PATCH]: KVM: Fix cmpxchg for writeback changes
Date: Wed, 25 Jul 2007 11:41:57 +0200 [thread overview]
Message-ID: <20070725094157.GA20665@hall.aurel32.net> (raw)
In-Reply-To: <46A7190A.3080500-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
On Wed, Jul 25, 2007 at 12:34:02PM +0300, Avi Kivity wrote:
> Aurelien Jarno wrote:
> > KVM: Fix writeback for cmpxchg instruction
> >
> > The writeback fixes (02c03a326a5df825cc01de426f72e160db2b9538) broke
> > cmpxchg emulation. The patch below fixes that.
> >
> > Signed-off-by: Aurelien Jarno <aurelien-rXXEIb44qovR7s880joybQ@public.gmane.org>
> >
[snip]
> But no_wb defaults to zero?
Oops right. So please find a new patch below.
KVM: Remove dead code in the cmpxchg instruction emulation
The writeback fixes (02c03a326a5df825cc01de426f72e160db2b9538) let
some dead code in the cmpxchg instruction emulation. Remove it.
Signed-off-by: Aurelien Jarno <aurelien-rXXEIb44qovR7s880joybQ@public.gmane.org>
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 21ce977..7b1baec 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -1274,8 +1274,6 @@ twobyte_insn:
src.orig_val = src.val;
src.val = _regs[VCPU_REGS_RAX];
emulate_2op_SrcV("cmp", src, dst, _eflags);
- /* Always write back. The question is: where to? */
- d |= Mov;
if (_eflags & EFLG_ZF) {
/* Success: write back to memory. */
dst.val = src.orig_val;
--
.''`. Aurelien Jarno | GPG: 1024D/F1BCDB73
: :' : Debian developer | Electrical Engineer
`. `' aurel32-8fiUuRrzOP0dnm+yROfE0A@public.gmane.org | aurelien-rXXEIb44qovR7s880joybQ@public.gmane.org
`- people.debian.org/~aurel32 | www.aurel32.net
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next prev parent reply other threads:[~2007-07-25 9:41 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-25 9:25 [PATCH]: KVM: Fix cmpxchg for writeback changes Aurelien Jarno
[not found] ` <20070725092506.GA19697-OqXK5JiLQY5aJl8KAwiEcA@public.gmane.org>
2007-07-25 9:34 ` Avi Kivity
[not found] ` <46A7190A.3080500-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-07-25 9:41 ` Aurelien Jarno [this message]
[not found] ` <20070725094157.GA20665-OqXK5JiLQY5aJl8KAwiEcA@public.gmane.org>
2007-07-25 9:54 ` Avi Kivity
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