From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50513) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eRVp0-0006FH-As for qemu-devel@nongnu.org; Tue, 19 Dec 2017 23:17:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eRVoy-0004q3-Ss for qemu-devel@nongnu.org; Tue, 19 Dec 2017 23:17:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34512) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eRVoy-0004ou-J8 for qemu-devel@nongnu.org; Tue, 19 Dec 2017 23:17:32 -0500 Date: Wed, 20 Dec 2017 06:17:28 +0200 From: "Michael S. Tsirkin" Message-ID: <20171220061654-mutt-send-email-mst@kernel.org> References: <1513350170-20168-1-git-send-email-den@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH v3 0/2] virtio: fix IO request length in virtio SCSI/block List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Denis V. Lunev" Cc: qemu-devel@nongnu.org, Stefan Hajnoczi , Kevin Wolf , Max Reitz , Paolo Bonzini , Richard Henderson , Eduardo Habkost On Tue, Dec 19, 2017 at 03:45:52PM +0300, Denis V. Lunev wrote: > On 12/15/2017 06:02 PM, Denis V. Lunev wrote: > > v2->v3 > > - added 2.12 machine types > > - added compat properties for 2.11 machine type > > > > v1->v2: > > - added max_segments property for virtblock device > > > > Signed-off-by: Denis V. Lunev > > CC: "Michael S. Tsirkin" > > CC: Stefan Hajnoczi > > CC: Kevin Wolf > > CC: Max Reitz > > CC: Paolo Bonzini > > CC: Richard Henderson > > CC: Eduardo Habkost > > > the patch appears to be problematic. > > We observe the following crashes under heavy load > > [ 2.348177] kernel BUG at drivers/virtio/virtio_ring.c:160! > [ 2.349382] invalid opcode: 0000 [#1] SMP > [ 2.350448] Modules linked in: xfs libcrc32c sr_mod cdrom sd_mod crc_t10dif crct10dif_generic virtio_scsi virtio_console virtio_net ata_generic pata_acpi crct10dif_pclmul crct10dif_common crc32c_intel serio_raw bochs_drm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm virtio_pci virtio_ring virtio i2c_core ata_piix libata floppy dm_mirror dm_region_hash dm_log dm_mod > [ 2.357149] CPU: 1 PID: 399 Comm: mount Not tainted 3.10.0-514.26.2.el7.x86_64 #1 > [ 2.358569] Hardware name: Virtuozzo KVM, BIOS 1.10.2-3.1.vz7.2 04/01/2014 > [ 2.359967] task: ffff8800362f4e70 ti: ffff880035b00000 task.ti: ffff880035b00000 > [ 2.361443] RIP: 0010:[] [] virtqueue_add_sgs+0x370/0x3c0 [virtio_ring] > [ 2.363171] RSP: 0018:ffff880035b03760 EFLAGS: 00010002 > [ 2.364419] RAX: ffff8800359b8800 RBX: 0000000000000082 RCX: 0000000000000003 > [ 2.365866] RDX: ffffea0000d9b7c2 RSI: ffff880035b037e0 RDI: ffff8800783dcfe0 > [ 2.367325] RBP: ffff880035b037b8 R08: ffff88003679d3c0 R09: 0000000000000020 > [ 2.368766] R10: ffff8800359c08c0 R11: ffff8800359c08c0 R12: ffff8800787a4948 > [ 2.370232] R13: ffff880035b037f8 R14: ffff880035b037f8 R15: 0000000000000020 > [ 2.371681] FS: 00007f38a0887880(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000 > [ 2.373233] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 2.374529] CR2: 00007f2090d276f8 CR3: 0000000036371000 CR4: 00000000000406e0 > [ 2.375982] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 2.377462] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > [ 2.378913] Stack: > [ 2.379846] ffff88003679d3c0 0000000100000000 ffff88003582d800 ffff880035b037e0 > [ 2.381389] 0000000335b03820 ffff8800359b8800 ffff88003679d3c0 ffff8800787a4948 > [ 2.382905] ffff8800359c0998 ffff8800359b8800 000000000000006c ffff880035b03870 > [ 2.384449] Call Trace: > [ 2.385420] [] virtscsi_kick_cmd+0x161/0x280 [virtio_scsi] > [ 2.386874] [] ? mempool_alloc+0x69/0x170 > [ 2.388189] [] virtscsi_queuecommand+0x12f/0x230 [virtio_scsi] > [ 2.389702] [] virtscsi_queuecommand_single+0x37/0x40 [virtio_scsi] > [ 2.391217] [] scsi_dispatch_cmd+0xaa/0x230 > [ 2.392537] [] scsi_request_fn+0x501/0x770 > [ 2.393832] [] __blk_run_queue+0x33/0x40 > [ 2.395103] [] queue_unplugged+0x2a/0xa0 > [ 2.396380] [] blk_flush_plug_list+0x1d8/0x230 > [ 2.397673] [] blk_finish_plug+0x14/0x40 > [ 2.398935] [] _xfs_buf_ioapply+0x334/0x460 [xfs] > [ 2.400286] [] ? xlog_bread_noalign+0xa8/0xe0 [xfs] > [ 2.401631] [] xfs_buf_submit_wait+0x5d/0x1d0 [xfs] > [ 2.402960] [] xlog_bread_noalign+0xa8/0xe0 [xfs] > [ 2.404306] [] xlog_bread+0x23/0x50 [xfs] > [ 2.405537] [] xlog_find_verify_cycle+0xf1/0x1b0 [xfs] > [ 2.406885] [] xlog_find_head+0x2f1/0x3e0 [xfs] > [ 2.408175] [] xlog_find_tail+0x43/0x2f0 [xfs] > [ 2.409432] [] ? try_to_wake_up+0x174/0x340 > [ 2.410673] [] xlog_recover+0x2d/0x190 [xfs] > [ 2.411927] [] ? xfs_trans_ail_init+0xab/0xd0 [xfs] > [ 2.413246] [] xfs_log_mount+0xea/0x2e0 [xfs] > [ 2.414490] [] xfs_mountfs+0x518/0x8b0 [xfs] > [ 2.415714] [] ? xfs_filestream_get_parent+0x80/0x80 [xfs] > [ 2.417100] [] ? xfs_mru_cache_create+0x129/0x190 [xfs] > [ 2.419226] [] xfs_fs_fill_super+0x3b3/0x4d0 [xfs] > [ 2.420473] [] mount_bdev+0x1b0/0x1f0 > [ 2.421575] [] ? xfs_parseargs+0xbe0/0xbe0 [xfs] > [ 2.422766] [] xfs_fs_mount+0x15/0x20 [xfs] > [ 2.423903] [] mount_fs+0x39/0x1b0 > [ 2.424955] [] ? __alloc_percpu+0x15/0x20 > [ 2.426054] [] vfs_kern_mount+0x5f/0xf0 > [ 2.427147] [] do_mount+0x24e/0xaa0 > [ 2.428170] [] ? strndup_user+0x4b/0xa0 > [ 2.429226] [] SyS_mount+0x96/0xf0 > [ 2.430242] [] system_call_fastpath+0x16/0x1b > [ 2.431351] Code: 5c e9 69 ff ff ff 31 db e9 17 fd ff ff 89 da 48 c7 c6 98 63 0b a0 48 c7 c7 a0 70 0b a0 31 c0 e8 a7 7f 28 e1 e9 d5 fd ff ff 0f 0b <0f> 0b 8b 55 c8 48 89 d9 48 c7 c6 c0 62 0b a0 48 c7 c7 78 70 0b > > The problem is presumed to be gone in very latest 4.14 kernel. > We believe that the problem is fixed with > > commit 44ed8089e991a60d614abe0ee4b9057a28b364e4 > Author: Richard W.M. Jones > Date: Thu Aug 10 17:56:51 2017 +0100 > > scsi: virtio: Reduce BUG if total_sg > virtqueue size to WARN. > > If using indirect descriptors, you can make the total_sg as large as you > want. If not, BUG is too serious because the function later returns > -ENOSPC. > > Signed-off-by: Richard W.M. Jones > Reviewed-by: Paolo Bonzini > Signed-off-by: Martin K. Petersen > > Thus I am going to add the property, but with default 126 :( > > Den About that, Paolo, you promised to propose a spec patch to relax the requirement. -- MST