Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932399AbaKMJMo (ORCPT ); Thu, 13 Nov 2014 04:12:44 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56663 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932065AbaKMJMl (ORCPT ); Thu, 13 Nov 2014 04:12:41 -0500 Message-ID: <546475FB.800@redhat.com> Date: Thu, 13 Nov 2014 17:12:27 +0800 From: Jason Wang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Cornelia Huck CC: rusty@rustcorp.com.au, mst@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH 2/2] virtio-net: fix buggy features advertised by host References: <1415857974-23326-1-git-send-email-jasowang@redhat.com> <1415857974-23326-2-git-send-email-jasowang@redhat.com> <20141113095326.3e296c77.cornelia.huck@de.ibm.com> In-Reply-To: <20141113095326.3e296c77.cornelia.huck@de.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/13/2014 04:53 PM, Cornelia Huck wrote: > On Thu, 13 Nov 2014 13:52:54 +0800 > Jason Wang wrote: > >> This patch tries to detect the possible buggy features advertised by host >> and fix them. One example is booting virtio-net with only ctrl_vq disabled, >> qemu may still advertise many features which depends on it. This will >> trigger several BUG()s in virtnet_send_command(). >> >> This patch utilizes the fix_features() method, and disables all features that >> depends on ctrl_vq if it was not advertised. >> >> This fixes the crash when booting with ctrl_vq=off. > That's a qemu device property, right? Might want to mention that, as > this line sounds like it is a kernel parameter. Right, ok. >> Cc: Rusty Russell >> Cc: Michael S. Tsirkin >> Signed-off-by: Jason Wang >> --- >> Changes from V1: >> - fix the cut-and-paste error >> --- >> drivers/net/virtio_net.c | 35 +++++++++++++++++++++++++++++++++++ >> 1 file changed, 35 insertions(+) >> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c >> index ec2a8b4..6ce125e 100644 >> --- a/drivers/net/virtio_net.c >> +++ b/drivers/net/virtio_net.c >> @@ -1948,6 +1948,40 @@ static int virtnet_restore(struct virtio_device *vdev) >> } >> #endif >> >> +static void virtnet_fix_features(struct virtio_device *dev) >> +{ >> + if (!virtio_has_feature(dev, VIRTIO_NET_F_CTRL_VQ)) { >> + if (virtio_has_feature(dev, VIRTIO_NET_F_CTRL_RX)) { >> + pr_warning("Disable VIRTIO_NET_F_CTRL_RX since host " >> + "does not advertise VIRTIO_NET_F_CTRL_VQ"); >> + virtio_disable_feature(dev, VIRTIO_NET_F_CTRL_RX); >> + } > You should probably use dev_warn() or so, so that the user can figure > out which device the message is for. And perhaps add "buggy hypervisor" > to the message to make clear that it's not a guest problem. Ok. > I also like the suggestion to use a dependency array. > Yes, will do it in next version. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/