From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932896AbdC2UTf (ORCPT ); Wed, 29 Mar 2017 16:19:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50930 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932781AbdC2UTS (ORCPT ); Wed, 29 Mar 2017 16:19:18 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A5CDF61B9C Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=mst@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com A5CDF61B9C Date: Wed, 29 Mar 2017 23:19:16 +0300 From: "Michael S. Tsirkin" To: Mike Galbraith Cc: Christoph Hellwig , Thorsten Leemhuis , virtio-dev@lists.oasis-open.org, Linux Kernel Mailing List , rjones@redhat.com Subject: Re: Random guest crashes since 5c34d002dcc7 ("virtio_pci: use shared interrupts for virtqueues") Message-ID: <20170329231738-mutt-send-email-mst@kernel.org> References: <20170323145622.GA31690@lst.de> <1490605644.14634.50.camel@gmx.de> <20170327170540.GA28715@lst.de> <1490638711.26533.44.camel@gmx.de> <1490768602.5950.25.camel@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1490768602.5950.25.camel@gmx.de> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 29 Mar 2017 20:19:17 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 29, 2017 at 08:23:22AM +0200, Mike Galbraith wrote: > On Mon, 2017-03-27 at 20:18 +0200, Mike Galbraith wrote: > > > BTW, WRT RT woes with $subject, I tried booting a generic kernel with > > threadirqs, and bingo, same deal, just a bit more painful than for RT, > > where there's no watchdog moaning accompanying the (preemptible) spin. > > BTW++: the last hunk of this bandaid may be a bug fix. With only the > first two, box tried to use uninitialized stuff on hibernate, went > boom. Looks like that may be possible without help from me. > > --- a/drivers/char/virtio_console.c > +++ b/drivers/char/virtio_console.c > @@ -2058,7 +2058,7 @@ static int virtcons_probe(struct virtio_ > portdev->max_nr_ports = 1; > > /* Don't test MULTIPORT at all if we're rproc: not a valid feature! */ > - if (!is_rproc_serial(vdev) && > + if (!is_rproc_serial(vdev) && !IS_ENABLED(CONFIG_IRQ_FORCED_THREADING) && > virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT, > struct virtio_console_config, max_nr_ports, > &portdev->max_nr_ports) == 0) { > @@ -2179,7 +2179,9 @@ static struct virtio_device_id id_table[ > > static unsigned int features[] = { > VIRTIO_CONSOLE_F_SIZE, > +#ifndef CONFIG_IRQ_FORCED_THREADING > VIRTIO_CONSOLE_F_MULTIPORT, > +#endif > }; These look kind of questionable. Is this part needed? > static struct virtio_device_id rproc_serial_id_table[] = { > @@ -2202,14 +2204,16 @@ static int virtcons_freeze(struct virtio > > vdev->config->reset(vdev); > > - virtqueue_disable_cb(portdev->c_ivq); > + if (use_multiport(portdev)) > + virtqueue_disable_cb(portdev->c_ivq); > cancel_work_sync(&portdev->control_work); > cancel_work_sync(&portdev->config_work); > /* > * Once more: if control_work_handler() was running, it would > * enable the cb as the last step. > */ > - virtqueue_disable_cb(portdev->c_ivq); > + if (use_multiport(portdev)) > + virtqueue_disable_cb(portdev->c_ivq); > remove_controlq_data(portdev); > > list_for_each_entry(port, &portdev->ports, list) { This looks real. No idea why would interrupt sharing trigger anything like this but go figure. Can you pls submit this separately with a signature? -- MST