From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NAh1A-000186-N2 for qemu-devel@nongnu.org; Wed, 18 Nov 2009 04:40:04 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NAh15-00017L-Ey for qemu-devel@nongnu.org; Wed, 18 Nov 2009 04:40:03 -0500 Received: from [199.232.76.173] (port=51105 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NAh15-00017I-93 for qemu-devel@nongnu.org; Wed, 18 Nov 2009 04:39:59 -0500 Received: from mx1.redhat.com ([209.132.183.28]:9196) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NAh14-0003E3-SS for qemu-devel@nongnu.org; Wed, 18 Nov 2009 04:39:59 -0500 Date: Wed, 18 Nov 2009 11:39:49 +0200 From: Gleb Natapov Subject: Re: [Qemu-devel] Stack corruption problem with SeaBIOS/gPXE under QEMU Message-ID: <20091118093949.GA18543@redhat.com> References: <4AFBEF9A.5010802@redhat.com> <20091114194745.GA12007@morn.localdomain> <4B01555B.1030109@redhat.com> <4B015B6C.4090000@redhat.com> <20091117022620.GA25962@morn.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091117022620.GA25962@morn.localdomain> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin O'Connor Cc: Glauber Costa , Naphtali Sprei , gpxe@etherboot.org, Avi Kivity , qemu-devel@nongnu.org On Mon, Nov 16, 2009 at 09:26:20PM -0500, Kevin O'Connor wrote: > On Mon, Nov 16, 2009 at 04:02:20PM +0200, Avi Kivity wrote: > >> Something that is likely related, I am seeing reboot failures in > >> seabios's pmm_free. Immediately after loading gpxe, seabios is in an > >> endless loop there, likely due to memory corruption. > >> > >> This is with -smp 2, rebooting Fedora 9 after installation. > > > > With gpxe disabled, rebooting works as expected. > > > > Note the tests were performed with the stack at 64K to avoid triggering > > the known issue. > > Hi Avi, > > Can you send the full qemu command line that you used? I can't seem > to reproduce this on my setup. > > I do see an issue if SeaBIOS's reboot vector is called (eg, by using > "sendkey ctrl-alt-delete" while still in the bios) because seabios > allows gpxe to modify itself, and on a seabios only reboot the gpxe > rom isn't recopied and gpxe therefore gets confused. However, on a > linux invoked reboot, it looks like a full machine reset occurs and > qemu recopies the gpxe rom, so that doesn't seem to be an issue. > Do we have the same problem with tpr patching rom (vapic,bin)? It modifies itself too. > BTW, how did you change the stack location? I've been changing > seabios by setting BUILD_STACK_ADDR to 0x7000 (or 0xfff0) in > src/config.h. > > -Kevin > -- Gleb.