Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751829AbaKQJRt (ORCPT ); Mon, 17 Nov 2014 04:17:49 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58553 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751712AbaKQJRq (ORCPT ); Mon, 17 Nov 2014 04:17:46 -0500 From: Jason Wang To: rusty@rustcorp.com.au, mst@redhat.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Jason Wang , Cornelia Huck , Wanlong Gao Subject: [PATCH V3 2/2] virtio-net: sanitize buggy features advertised by host Date: Mon, 17 Nov 2014 17:17:18 +0800 Message-Id: <1416215838-21700-2-git-send-email-jasowang@redhat.com> In-Reply-To: <1416215838-21700-1-git-send-email-jasowang@redhat.com> References: <1416215838-21700-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch tries to detect the possible buggy features advertised by host and sanitize 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 sanitize_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 using qemu. Cc: Rusty Russell Cc: Michael S. Tsirkin Cc: Cornelia Huck Cc: Wanlong Gao Signed-off-by: Jason Wang --- Changes from V1: - fix the cut-and-paste error Changes from V2: - loop through an array of feature bits - switch to use dev_warn() --- drivers/net/virtio_net.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index ec2a8b4..6fadd8c 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1948,6 +1948,31 @@ static int virtnet_restore(struct virtio_device *vdev) } #endif +static void virtnet_sanitize_features(struct virtio_device *dev) +{ + unsigned int features_for_ctrl_vq[] = { + VIRTIO_NET_F_CTRL_RX, + VIRTIO_NET_F_CTRL_VLAN, + VIRTIO_NET_F_GUEST_ANNOUNCE, + VIRTIO_NET_F_MQ, + VIRTIO_NET_F_CTRL_MAC_ADDR + }; + int i; + + if (!virtio_has_feature(dev, VIRTIO_NET_F_CTRL_VQ)) { + for (i = 0; i < ARRAY_SIZE(features_for_ctrl_vq); i++) { + unsigned int f = features_for_ctrl_vq[i]; + if (virtio_has_feature(dev, f)) { + virtio_disable_feature(dev, f); + dev_warn(&dev->dev, + "buggy hyperviser: disable feature " + "0x%x since VIRTIO_NET_F_CTRL_VQ was " + "not advertised.\n", f); + } + } + } +} + static struct virtio_device_id id_table[] = { { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID }, { 0 }, @@ -1975,6 +2000,7 @@ static struct virtio_driver virtio_net_driver = { .probe = virtnet_probe, .remove = virtnet_remove, .config_changed = virtnet_config_changed, + .sanitize_features = virtnet_sanitize_features, #ifdef CONFIG_PM_SLEEP .freeze = virtnet_freeze, .restore = virtnet_restore, -- 1.9.1 -- 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/