From patchwork Mon Dec 26 07:49:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 13081697 X-Patchwork-Delegate: kuba@kernel.org 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD68DC4332F for ; Mon, 26 Dec 2022 07:51:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231913AbiLZHvD (ORCPT ); Mon, 26 Dec 2022 02:51:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231825AbiLZHu0 (ORCPT ); Mon, 26 Dec 2022 02:50:26 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2EF476160 for ; Sun, 25 Dec 2022 23:49:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1672040980; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cQQAF2roIs1AkbrATZH+Dx5zgxJxII5XuDrBnrFmmR0=; b=fvQ9pBghg2PDnyPDrafgNgpe4X28DvyXSyDUJJ/QJL+B+X0xXbl8rRCky7fV+EWAi7Ix2h XykaH+cPqPYEUJ4uOO6sL1gkAR2QkwQHmYxhxeWbpOWMjU+SfU8QBw+DM0EbYbeK/y2PsK +ViIZOYEq/OVRnsh7bK/InxEnWrdt8E= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-198-fpqLXZzLMJGNQN3y84BlPg-1; Mon, 26 Dec 2022 02:49:37 -0500 X-MC-Unique: fpqLXZzLMJGNQN3y84BlPg-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A4982101A52E; Mon, 26 Dec 2022 07:49:36 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-100.pek2.redhat.com [10.72.13.100]) by smtp.corp.redhat.com (Postfix) with ESMTP id BE333492B00; Mon, 26 Dec 2022 07:49:31 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, maxime.coquelin@redhat.com, alvaro.karsz@solid-run.com, eperezma@redhat.com Subject: [PATCH 4/4] virtio-net: sleep instead of busy waiting for cvq command Date: Mon, 26 Dec 2022 15:49:08 +0800 Message-Id: <20221226074908.8154-5-jasowang@redhat.com> In-Reply-To: <20221226074908.8154-1-jasowang@redhat.com> References: <20221226074908.8154-1-jasowang@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org We used to busy waiting on the cvq command this tends to be problematic since: 1) CPU could wait for ever on a buggy/malicous device 2) There's no wait to terminate the process that triggers the cvq command So this patch switch to use virtqueue_wait_for_used() to sleep with a timeout (1s) instead of busy polling for the cvq command forever. This gives the scheduler a breath and can let the process can respond to asignal. If the device doesn't respond in the timeout, break the device. Signed-off-by: Jason Wang --- Changes since V1: - break the device when timeout - get buffer manually since the virtio core check more_used() instead --- drivers/net/virtio_net.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index efd9dd55828b..6a2ea64cfcb5 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -405,6 +405,7 @@ static void disable_rx_mode_work(struct virtnet_info *vi) vi->rx_mode_work_enabled = false; spin_unlock_bh(&vi->rx_mode_lock); + virtqueue_wake_up(vi->cvq); flush_work(&vi->rx_mode_work); } @@ -1497,6 +1498,11 @@ static bool try_fill_recv(struct virtnet_info *vi, struct receive_queue *rq, return !oom; } +static void virtnet_cvq_done(struct virtqueue *cvq) +{ + virtqueue_wake_up(cvq); +} + static void skb_recv_done(struct virtqueue *rvq) { struct virtnet_info *vi = rvq->vdev->priv; @@ -1984,6 +1990,8 @@ static int virtnet_tx_resize(struct virtnet_info *vi, return err; } +static int virtnet_close(struct net_device *dev); + /* * Send command via the control virtqueue and check status. Commands * supported by the hypervisor, as indicated by feature bits, should @@ -2026,14 +2034,14 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd, if (unlikely(!virtqueue_kick(vi->cvq))) return vi->ctrl->status == VIRTIO_NET_OK; - /* Spin for a response, the kick causes an ioport write, trapping - * into the hypervisor, so the request should be handled immediately. - */ - while (!virtqueue_get_buf(vi->cvq, &tmp) && - !virtqueue_is_broken(vi->cvq)) - cpu_relax(); + if (virtqueue_wait_for_used(vi->cvq)) { + virtqueue_get_buf(vi->cvq, &tmp); + return vi->ctrl->status == VIRTIO_NET_OK; + } - return vi->ctrl->status == VIRTIO_NET_OK; + netdev_err(vi->dev, "CVQ command timeout, break the virtio device."); + virtio_break_device(vi->vdev); + return VIRTIO_NET_ERR; } static int virtnet_set_mac_address(struct net_device *dev, void *p) @@ -3526,7 +3534,7 @@ static int virtnet_find_vqs(struct virtnet_info *vi) /* Parameters for control virtqueue, if any */ if (vi->has_cvq) { - callbacks[total_vqs - 1] = NULL; + callbacks[total_vqs - 1] = virtnet_cvq_done; names[total_vqs - 1] = "control"; }