From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751862AbaJTMH6 (ORCPT ); Mon, 20 Oct 2014 08:07:58 -0400 Received: from casper.infradead.org ([85.118.1.10]:44970 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751119AbaJTMH4 (ORCPT ); Mon, 20 Oct 2014 08:07:56 -0400 Date: Mon, 20 Oct 2014 13:07:50 +0100 From: Thomas Graf To: "Michael S. Tsirkin" Cc: linux-kernel@vger.kernel.org, Rusty Russell , virtualization@lists.linux-foundation.org, linux-scsi@vger.kernel.org, linux-s390@vger.kernel.org, v9fs-developer@lists.sourceforge.net, netdev@vger.kernel.org, kvm@vger.kernel.org, Amit Shah , Cornelia Huck , Christian Borntraeger , "David S. Miller" , Paolo Bonzini , Arnd Bergmann , Greg Kroah-Hartman Subject: Re: [PATCH v4 13/25] virtio_console: enable VQs early Message-ID: <20141020120750.GA18561@casper.infradead.org> References: <1413114332-626-1-git-send-email-mst-v4@redhat.com> <1413114332-626-14-git-send-email-mst-v4@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1413114332-626-14-git-send-email-mst-v4@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/13/14 at 10:50am, Michael S. Tsirkin wrote: > virtio spec requires drivers to set DRIVER_OK before using VQs. > This is set automatically after probe returns, virtio console violated this > rule by adding inbufs, which causes the VQ to be used directly within > probe. > > To fix, call virtio_device_ready before using VQs. > > Signed-off-by: Michael S. Tsirkin > --- > drivers/char/virtio_console.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > index b585b47..6ebe8f6 100644 > --- a/drivers/char/virtio_console.c > +++ b/drivers/char/virtio_console.c > @@ -1449,6 +1449,8 @@ static int add_port(struct ports_device *portdev, u32 id) > spin_lock_init(&port->outvq_lock); > init_waitqueue_head(&port->waitqueue); > > + virtio_device_ready(portdev->vdev); > + > /* Fill the in_vq with buffers so the host can send us data. */ > nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock); > if (!nr_added_bufs) { Seems like probe and add_port() now both set VIRTIO_CONFIG_S_DRIVER_OK 1.839658] kernel BUG at include/linux/virtio_config.h:125! [ 1.839995] invalid opcode: 0000 [#1] SMP [ 1.840169] Modules linked in: serio_raw virtio_balloon pcspkr virtio_net virtio_console soundcore parport_pc floppy pvpanic parport i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc qxl drm_kms_helper ttm drm virtio_blk i2c_core virtio_pci ata_generic virtio_ring virtio pata_acpi [ 1.840169] CPU: 2 PID: 266 Comm: kworker/2:2 Not tainted 3.17.0+ #1 [ 1.840169] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 1.840169] Workqueue: events control_work_handler [virtio_console] [ 1.840169] task: ffff8800364bc840 ti: ffff880078490000 task.ti: ffff880078490000 [ 1.840169] RIP: 0010:[] [] virtio_device_ready.part.12+0x4/0x6 [virtio_console] [ 1.840169] RSP: 0018:ffff880078493c78 EFLAGS: 00010202 [ 1.840169] RAX: 0000000000000007 RBX: ffff880036406200 RCX: 0000000000006e39 [ 1.840169] RDX: 000000000000c0b2 RSI: 0000000000000000 RDI: 000000000001c0b2 [ 1.840169] RBP: ffff880078493c78 R08: ffffffff81d2c6f8 R09: 0000000000000000 [ 1.840169] R10: 0000000000000001 R11: ffff8800364bd000 R12: ffff880036618400 [ 1.840169] R13: 0000000000000001 R14: ffff8800368c6800 R15: ffff880036406220 [ 1.840169] FS: 0000000000000000(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000 [ 1.840169] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1.840169] CR2: 00007f1c31c90000 CR3: 0000000001c14000 CR4: 00000000000006e0 [ 1.840169] Stack: [ 1.840169] ffff880078493ce8 ffffffffa01d886a ffff880000000001 ffffffff810e20cd [ 1.840169] ffff880078493cb8 0000000000000282 0000000000000000 0000000087f90194 [ 1.840169] ffff880078493ce8 ffff88007ab1d4e0 ffff880036618498 ffff880036618410 [ 1.840169] Call Trace: [ 1.840169] [] add_port+0x40a/0x440 [virtio_console] [ 1.840169] [] ? trace_hardirqs_on+0xd/0x10 [ 1.840169] [] control_work_handler+0x3ca/0x420 [virtio_console] [ 1.840169] [] ? process_one_work+0x15b/0x530 [ 1.840169] [] process_one_work+0x1d4/0x530 [ 1.840169] [] ? process_one_work+0x15b/0x530 [ 1.840169] [] worker_thread+0x11b/0x490 [ 1.840169] [] ? process_one_work+0x530/0x530 [ 1.840169] [] kthread+0xf3/0x110 [ 1.840169] [] ? _raw_spin_unlock_irq+0x30/0x50 [ 1.840169] [] ? kthread_create_on_node+0x240/0x240 [ 1.840169] [] ret_from_fork+0x7c/0xb0 [ 1.840169] [] ? kthread_create_on_node+0x240/0x240 [ 1.840169] Code: ff 49 89 c4 4d 85 e4 0f 8f 25 ff ff ff eb ad 48 c7 c0 f4 ff ff ff e9 17 ff ff ff e8 f5 cd eb e0 90 55 48 89 e5 0f 0b 55 48 89 e5 <0f> 0b 55 48 89 e5 0f 0b 55 48 89 e5 e8 99 e2 ff ff 48 c7 c7 c0 [ 1.840169] RIP [] virtio_device_ready.part.12+0x4/0x6 [virtio_console] [ 1.840169] RSP