From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Vivier Subject: Re: Unable to handle kernel paging request Date: Thu, 27 Sep 2007 18:54:45 +0200 Message-ID: <46FBE055.2040904@bull.net> References: <46FBDA8A.8030109@bull.net> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============2080202894==" Cc: kvm-devel To: Laurent Vivier Return-path: In-Reply-To: <46FBDA8A.8030109-6ktuUTfB/bM@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 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --===============2080202894== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig0AD6FCB0332E89BA83E1E57A" This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig0AD6FCB0332E89BA83E1E57A Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Correct me if I'm wrong, perhaps it's the bug Nitin is hunting. There is always something wrong in the management in the REP prefix. I think what is happen is: - we have a REP prefix, we save ECX and EIP. - we set c->dst to emulate a "stos" - goto writeback - writeback: we try a "write_emulated()" with c->dst - write_emulated failed() AND WE DON'T RESTORE ECX AND EIP -> it's bad...= - exit to QEMU - re-enter in x86_emulate_insn() with already modified ECX and EIP. Any comment ? (Yes, I know, it's again another bug I've introduced into KVM...) Laurent Laurent Vivier wrote: > Hi, >=20 > booting a FC6 on my intel box (xeon) with a kernel 2.6.22.5 and KVM git= , I had > the following error (not reproducible): >=20 > # kvm-userspace/qemu/x86_64-softmmu/qemu-system-x86_64 -hda fc6.qcow2 -= net nic > -net tap -serial stdio -smp 4 > ... > INIT: version 2.86 booting > Welcome to Fedora Core > Press 'I' to enter interactive startup. > Setting clock (utc): Thu Sep 27 18:06:27 CEST 2007 [ OK ] > Starting udev: Unable to handle kernel paging request at ffffffff880e90= 00 RIP: > [] sys_init_module+0x985/0x1786 > PGD 203067 PUD 205063 PMD 7fc4067 PTE 6b50163 > Oops: 0002 [1] SMP > CPU 1 > Modules linked in: dm_snapshot dm_zero dm_mirror dm_mod ata_piix libata= sd_mod s > csi_mod ext3 jbd mbcache ehci_hcd ohci_hcd uhci_hcd > Pid: 641, comm: modprobe Not tainted 2.6.22.5 #1 > RIP: 0010:[] [] sys_init_module+0x= 985/0x178 > 6 > RSP: 0018:ffff810006399e68 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: ffffc20000090a20 RCX: 0000000000000f84 > RDX: ffffffff880e6000 RSI: 0000000000000163 RDI: ffffffff880e9000 > RBP: 0000000000000026 R08: ffff810007d94254 R09: 00000000000050cf > R10: 0000000000000000 R11: 0000000000000001 R12: ffffc2000007c300 > R13: 0000000000000004 R14: ffffc200000900e0 R15: 00002ab868ac2010 > FS: 00002ab8690096e0(0000) GS:ffff810007d94280(0000) knlGS:00000000000= 00000 > CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > CR2: ffffffff880e9000 CR3: 0000000007cfd000 CR4: 00000000000006e0 > Process modprobe (pid: 641, threadinfo ffff810006398000, task ffff81000= 788e000) > Stack: 00000000000276d8 0000000000000000 0000000000000000 000000000608= f340 > 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > 0000000000000000 0000000000000000 ffffc200000a2328 ffff810006402000 > Call Trace: > [] vfs_read+0xcb/0x173 > [] system_call+0x7e/0x83 >=20 >=20 > Code: f3 aa 49 89 94 24 88 01 00 00 49 8b bc 24 90 01 00 00 e8 32 > RIP [] sys_init_module+0x985/0x1786 > RSP > CR2: ffffffff880e9000 >=20 >=20 > The instruction at [] sys_init_module+0x985/0x1786 is= : >=20 > 0xffffffff8104ebc1 : rep stos %al,%es:(%rdi)= >=20 > Any idea of what happened ? >=20 > Laurent >=20 >=20 > -----------------------------------------------------------------------= - >=20 > -----------------------------------------------------------------------= -- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2005. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ >=20 >=20 > -----------------------------------------------------------------------= - >=20 > _______________________________________________ > kvm-devel mailing list > kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org > https://lists.sourceforge.net/lists/listinfo/kvm-devel --=20 ------------- Laurent.Vivier-6ktuUTfB/bM@public.gmane.org -------------- "Software is hard" - Donald Knuth --------------enig0AD6FCB0332E89BA83E1E57A Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.7 (GNU/Linux) iD8DBQFG++BY9Kffa9pFVzwRAj9zAKDG7lcVMnF+hGD+OAhhKZrGIIyBtQCcCel6 LI94drUbJdMdlB2o6JdDGqg= =GTYK -----END PGP SIGNATURE----- --------------enig0AD6FCB0332E89BA83E1E57A-- --===============2080202894== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ --===============2080202894== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ kvm-devel mailing list kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org https://lists.sourceforge.net/lists/listinfo/kvm-devel --===============2080202894==--