From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1H5epy-0001TT-54 for qemu-devel@nongnu.org; Sat, 13 Jan 2007 04:06:06 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1H5epx-0001Sa-8x for qemu-devel@nongnu.org; Sat, 13 Jan 2007 04:06:05 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1H5epw-0001SP-O4 for qemu-devel@nongnu.org; Sat, 13 Jan 2007 04:06:05 -0500 Received: from [194.25.134.17] (helo=mailout02.sul.t-online.com) by monty-python.gnu.org with esmtp (Exim 4.52) id 1H5epw-0006Ch-6Z for qemu-devel@nongnu.org; Sat, 13 Jan 2007 04:06:04 -0500 Message-ID: <45A8A0FB.3080005@t-online.de> Date: Sat, 13 Jan 2007 10:06:03 +0100 From: Werner Dittmann MIME-Version: 1.0 Subject: Re: [Qemu-devel] problem with 64/64 guest running grub References: <20070108135326.GA21227@silverwood.ncultra.org> <45A284D6.2080805@t-online.de> In-Reply-To: <45A284D6.2080805@t-online.de> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: ncmike@ncultra.org Doing some more tests and trying to get more info about the problem shows some common behaviours: - the problems are with the x86_64 emulation regardless if it is running on a 32bit or 64bit host (in my case always Linux host) - The problems happen in all qemu modes: no kqemu, user kqemu, kernel kqemu. The main difference: happens on different times during the installation process - It happens (at least this is what I can see) only if the 64 bit kernel that runs in qemu-system-x86_64 executes a 32 bit application. For example grub is a 32 bit application that runs in the 64bit kernel, some installation programs (at least in Suse) are also 32bit applications. The last statement is supported by the following oberservation: when Qemu crashes or hangs I very often see some strange register values, for example: RBX=ffffffff80523028 RSP=ffffffff80522dc0 RIP=ffffffff8025e67c If you remove the ff s then you have e.g. a instrution pointer address that is usually a valid address of a 32bit environment. IMHO something could be wrong with 32bit support inside qemu-system-x86_64. Any more ideas where to look to "embrace" the problem? Regards, Werner Werner Dittmann wrote: > Same happen to Suse 64 host/64 guest system (Suse 10.1). A 32-bit > guest system install quite well. > > My trace shows the same symptom: Qemu seems to loop in a very tight > loop. Sometimes (using infoe registers rapidly) I can even see that > it seems to switch to 32bit mode inside the guest kernel maybe because > a 32 bit application is running? > > No kqemu is involved when running the 64bit guest, started with > -no-kqemu. > > As mike wrote: any hint how I can help to tackle the problem is > appreciated. > > > Regards, > Werner > > > Mike Day wrote: >> I'm having a problem with qemu (cvs and 0.8.2) running on a 64 bit >> athlon x2 with a 64 bit guest. When installing edgy in a new 64-bit >> guest, the guest always freezes when installing grub on the boot >> partition. >> This only happens with a 64/64 system. I can run the guest in qemu (as >> opposed to >> qemu-system-x86_64) and use grub to install itself, but if I try to do >> the same thing with qemu-system-x86_64 it hangs. >> After generating a trace file and stepping through the hang in gdb it >> looks like the guest is getting overwhhelmed with interrupts. It >> reminds me of a situation where some device driver is forgetting to >> issue an eoi and the interrupt line is remaining on, which means that >> the guest can never make any progress advancing the instruction >> pointer. >> >> I've placed a compressed log file at >> http://www.ncultra.org/qemu.log.tgz >> >> I'd be happy to spend some more time runnign this down - if anyone has >> any suggestions on how I should proceed I'd be grateful. >> Mike >> >> > > > > _______________________________________________ > Qemu-devel mailing list > Qemu-devel@nongnu.org > http://lists.nongnu.org/mailman/listinfo/qemu-devel >