From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aurelien Jarno Subject: Re: [PATCH]: KVM: Fix cmpxchg for writeback changes Date: Wed, 25 Jul 2007 11:41:57 +0200 Message-ID: <20070725094157.GA20665@hall.aurel32.net> References: <20070725092506.GA19697@hall.aurel32.net> <46A7190A.3080500@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Avi Kivity Return-path: Content-Disposition: inline In-Reply-To: <46A7190A.3080500-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.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 > > [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 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 ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/