From patchwork Wed Apr 10 05:44:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 13623588 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2BACDCD1297 for ; Wed, 10 Apr 2024 05:52:55 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ruQon-0006Et-Vt; Wed, 10 Apr 2024 01:48:22 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ruQoR-00050n-FP; Wed, 10 Apr 2024 01:47:59 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ruQoO-00027V-4E; Wed, 10 Apr 2024 01:47:59 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 54CB55D500; Wed, 10 Apr 2024 08:46:17 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id 1611AB0167; Wed, 10 Apr 2024 08:44:19 +0300 (MSK) Received: (nullmailer pid 4182123 invoked by uid 1000); Wed, 10 Apr 2024 05:44:16 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Yajun Wu , Jiri Pirko , "Michael S . Tsirkin" , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Michael Tokarev Subject: [Stable-7.2.11 40/41] hw/net/virtio-net: fix qemu set used ring flag even vhost started Date: Wed, 10 Apr 2024 08:44:01 +0300 Message-Id: <20240410054416.4181891-40-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Yajun Wu When vhost-user or vhost-kernel is handling virtio net datapath, QEMU should not touch used ring. But with vhost-user socket reconnect scenario, in a very rare case (has pending kick event). VRING_USED_F_NO_NOTIFY is set by QEMU in following code path: #0 virtio_queue_split_set_notification (vq=0x7ff5f4c920a8, enable=0) at ../hw/virtio/virtio.c:511 #1 0x0000559d6dbf033b in virtio_queue_set_notification (vq=0x7ff5f4c920a8, enable=0) at ../hw/virtio/virtio.c:576 #2 0x0000559d6dbbbdbc in virtio_net_handle_tx_bh (vdev=0x559d703a6aa0, vq=0x7ff5f4c920a8) at ../hw/net/virtio-net.c:2801 #3 0x0000559d6dbf4791 in virtio_queue_notify_vq (vq=0x7ff5f4c920a8) at ../hw/virtio/virtio.c:2248 #4 0x0000559d6dbf79da in virtio_queue_host_notifier_read (n=0x7ff5f4c9211c) at ../hw/virtio/virtio.c:3525 #5 0x0000559d6d9a5814 in virtio_bus_cleanup_host_notifier (bus=0x559d703a6a20, n=1) at ../hw/virtio/virtio-bus.c:321 #6 0x0000559d6dbf83c9 in virtio_device_stop_ioeventfd_impl (vdev=0x559d703a6aa0) at ../hw/virtio/virtio.c:3774 #7 0x0000559d6d9a55c8 in virtio_bus_stop_ioeventfd (bus=0x559d703a6a20) at ../hw/virtio/virtio-bus.c:259 #8 0x0000559d6d9a53e8 in virtio_bus_grab_ioeventfd (bus=0x559d703a6a20) at ../hw/virtio/virtio-bus.c:199 #9 0x0000559d6dbf841c in virtio_device_grab_ioeventfd (vdev=0x559d703a6aa0) at ../hw/virtio/virtio.c:3783 #10 0x0000559d6d9bde18 in vhost_dev_enable_notifiers (hdev=0x559d707edd70, vdev=0x559d703a6aa0) at ../hw/virtio/vhost.c:1592 #11 0x0000559d6d89a0b8 in vhost_net_start_one (net=0x559d707edd70, dev=0x559d703a6aa0) at ../hw/net/vhost_net.c:266 #12 0x0000559d6d89a6df in vhost_net_start (dev=0x559d703a6aa0, ncs=0x559d7048d890, data_queue_pairs=31, cvq=0) at ../hw/net/vhost_net.c:412 #13 0x0000559d6dbb5b89 in virtio_net_vhost_status (n=0x559d703a6aa0, status=15 '\017') at ../hw/net/virtio-net.c:311 #14 0x0000559d6dbb5e34 in virtio_net_set_status (vdev=0x559d703a6aa0, status=15 '\017') at ../hw/net/virtio-net.c:392 #15 0x0000559d6dbb60d8 in virtio_net_set_link_status (nc=0x559d7048d890) at ../hw/net/virtio-net.c:455 #16 0x0000559d6da64863 in qmp_set_link (name=0x559d6f0b83d0 "hostnet1", up=true, errp=0x7ffdd76569f0) at ../net/net.c:1459 #17 0x0000559d6da7226e in net_vhost_user_event (opaque=0x559d6f0b83d0, event=CHR_EVENT_OPENED) at ../net/vhost-user.c:301 #18 0x0000559d6ddc7f63 in chr_be_event (s=0x559d6f2ffea0, event=CHR_EVENT_OPENED) at ../chardev/char.c:62 #19 0x0000559d6ddc7fdc in qemu_chr_be_event (s=0x559d6f2ffea0, event=CHR_EVENT_OPENED) at ../chardev/char.c:82 This issue causes guest kernel stop kicking device and traffic stop. Add vhost_started check in virtio_net_handle_tx_bh to fix this wrong VRING_USED_F_NO_NOTIFY set. Signed-off-by: Yajun Wu Reviewed-by: Jiri Pirko Acked-by: Michael S. Tsirkin Message-ID: <20240402045109.97729-1-yajunw@nvidia.com> [PMD: Use unlikely()] Signed-off-by: Philippe Mathieu-Daudé (cherry picked from commit 4c54f5bc8e1d38f15cc35b6a6932d8fbe219c692) Signed-off-by: Michael Tokarev diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 57d5a377c8..b6177a6afe 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -2746,6 +2746,10 @@ static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq) VirtIONet *n = VIRTIO_NET(vdev); VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))]; + if (unlikely(n->vhost_started)) { + return; + } + if (unlikely((n->status & VIRTIO_NET_S_LINK_UP) == 0)) { virtio_net_drop_tx_queue_data(vdev, vq); return;