From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48210) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VVNqj-0007Bz-Hb for qemu-devel@nongnu.org; Sun, 13 Oct 2013 11:45:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VVNqe-00061L-63 for qemu-devel@nongnu.org; Sun, 13 Oct 2013 11:44:57 -0400 Received: from dan.rpsys.net ([93.97.175.187]:64294) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VVNqd-00060z-RI for qemu-devel@nongnu.org; Sun, 13 Oct 2013 11:44:52 -0400 Received: from localhost (dan.rpsys.net [127.0.0.1]) by dan.rpsys.net (8.14.4/8.14.4/Debian-2.1ubuntu1) with ESMTP id r9DFinZr006297 for ; Sun, 13 Oct 2013 16:44:49 +0100 Received: from dan.rpsys.net ([127.0.0.1]) by localhost (dan.rpsys.net [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 3RHnoFP3puvf for ; Sun, 13 Oct 2013 16:44:49 +0100 (BST) Received: from [192.168.3.10] (rpvlan0 [192.168.3.10]) (authenticated bits=0) by dan.rpsys.net (8.14.4/8.14.4/Debian-2.1ubuntu1) with ESMTP id r9DFijdk006293 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NOT) for ; Sun, 13 Oct 2013 16:44:47 +0100 Message-ID: <1381679082.29912.223.camel@ted> From: Richard Purdie Date: Sun, 13 Oct 2013 16:44:42 +0100 In-Reply-To: <1380576057.18603.465.camel@ted> References: <1380576057.18603.465.camel@ted> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [BUG/PATCH] Fix i386 SSE status flag corruption List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org On Mon, 2013-09-30 at 22:20 +0100, Richard Purdie wrote: > This is a combination of bug report and patch. I'm not sure if you'll want to fix it > like this but it illustrates the problem and should be easy to fix based on this. > > When we restore the mxcsr register with FXRSTOR, we need to update the various SSE > status flags in CPUX86State by calling update_sse_status(). If we don't, we end up > using the status bits from some other context with interesting results. > > I used a function prototype since it makes the fix clear, some code rearrangement > might be needed ultimately. > > Signed-off-by: Richard Purdie Ping? This seems to be quite nasty SSE register corruption and it would be nice to get it fixed. Happy to rework the patch if needed, am just not sure the best way to handle moving the function if that is what is needed. Cheers, Richard > Index: qemu-1.5.0/target-i386/fpu_helper.c > =================================================================== > --- qemu-1.5.0.orig/target-i386/fpu_helper.c 2013-09-30 18:46:39.283377648 +0000 > +++ qemu-1.5.0/target-i386/fpu_helper.c 2013-09-30 18:46:56.895377232 +0000 > @@ -1149,6 +1149,8 @@ > } > } > > +static void update_sse_status(CPUX86State *env); > + > void helper_fxrstor(CPUX86State *env, target_ulong ptr, int data64) > { > int i, fpus, fptag, nb_xmm_regs; > @@ -1180,6 +1182,7 @@ > if (env->cr[4] & CR4_OSFXSR_MASK) { > /* XXX: finish it */ > env->mxcsr = cpu_ldl_data(env, ptr + 0x18); > + update_sse_status(env); > /* cpu_ldl_data(env, ptr + 0x1c); */ > if (env->hflags & HF_CS64_MASK) { > nb_xmm_regs = 16; > >