From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NAhE7-0006X1-Gd for qemu-devel@nongnu.org; Wed, 18 Nov 2009 04:53:27 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NAhE2-0006Ud-Qn for qemu-devel@nongnu.org; Wed, 18 Nov 2009 04:53:27 -0500 Received: from [199.232.76.173] (port=34637 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NAhE2-0006UH-Dj for qemu-devel@nongnu.org; Wed, 18 Nov 2009 04:53:22 -0500 Received: from mx1.redhat.com ([209.132.183.28]:1025) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NAhE1-0005Yz-OK for qemu-devel@nongnu.org; Wed, 18 Nov 2009 04:53:22 -0500 Date: Wed, 18 Nov 2009 11:53:12 +0200 From: Gleb Natapov Subject: Re: [Qemu-devel] Stack corruption problem with SeaBIOS/gPXE under QEMU Message-ID: <20091118095312.GB18543@redhat.com> References: <4AFBEF9A.5010802@redhat.com> <20091114194745.GA12007@morn.localdomain> <4B01555B.1030109@redhat.com> <4B015B6C.4090000@redhat.com> <20091117022620.GA25962@morn.localdomain> <20091118093949.GA18543@redhat.com> <4BEC722D-2E27-4591-BF99-1935C18C6412@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4BEC722D-2E27-4591-BF99-1935C18C6412@suse.de> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: gpxe@etherboot.org, Glauber Costa , qemu-devel@nongnu.org, Kevin O'Connor , Avi Kivity , Naphtali Sprei On Wed, Nov 18, 2009 at 10:49:37AM +0100, Alexander Graf wrote: > > On 18.11.2009, at 10:39, Gleb Natapov wrote: > > >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. > > Are you sure vapic.bin still works with SeaBIOS? I've had to modify > the multiboot and linuxboot code to write to the stack because the > code section of the option rom was read only. > I tested it with SeaBIOS and it worked. Actually vapic.bin doesn't modifies itself during BIOS run. Part of vapic.bin are modified by QEMU and other part are modified during Windows run. -- Gleb.