From patchwork Thu Dec 22 06:04:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 35624 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:e747:0:0:0:0:0 with SMTP id c7csp160893wrn; Wed, 21 Dec 2022 22:15:07 -0800 (PST) X-Google-Smtp-Source: AMrXdXuG30lxzEKDMFufMaqdKr+ohMApKzlbJE/9/ZVIKUMtDqnbWiDhQzsp+rCpjDLGlDzSc8Y3 X-Received: by 2002:a17:907:a508:b0:7c1:539b:d028 with SMTP id vr8-20020a170907a50800b007c1539bd028mr3552020ejc.48.1671689707479; Wed, 21 Dec 2022 22:15:07 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1671689707; cv=none; d=google.com; s=arc-20160816; b=WY+rvCtR+e4h2mXp51x/8b2yiWyAnHl2+ZPMdsU33+D7xNdoo5SUWMO5bmTy+33V5N 6FTSkF8ytN0AkeXqYMCAbFiqSQyWuNba9y7FseMypUc2/HRI+ZsbFKcdEBDSrIKgOpJ4 Wnte6OI5ANmyA8+jLfN9e5N+5SpoMMq1t/8vPpK5K9Uov1IJg0tlCsBcaM2X1mC3XbCA p6cdqArkPuFfsBwQhvWXLwRKbSvKvuU1OwjRmxOrnvfPGDU5Lmj9ASpiZmCRxxs0HGlS XIc/NDfnWkq8VBJriz9zDzKUI3rTcKLcXnEA11AG3NfgvoQ9Tc2XgLgwC42iVfIUKxQT Gdlw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=iq4cHvbMQpVcmBqe5fyUmrngiKVykMmjcTZb1s9VM+M=; b=VY+CEoqGALLyOlLWVQnHV/uXialUwMPesY2Kvl81HoWWNXeX3YBjvaINcwPghDvTTQ fyyYImfI9qYb7elJByWELSGoOM1tlWzdLP8wUc0mLiFJbVgiQLCva6CHOGCRa0LIYC9m pIHl4QrTmK0xfaqQMlYy91yDNNrony60R+kFz/MXDrWnJZMeHczqZ9a1wsXDgaKmHYU7 pzeUiiN3Gym9woghR5i9t92O4w1wo5XFc2A3ZTzuFKlEhVrErZKBzQrS98TKT2zfDJkl Ocg0YmQ6Xsk5vVlRWVUAFdGeCsxJ0HVMpkAgmatETeYbwAjHViQhv1oFSFfCWPSggeZ7 j6GA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=XisQSdIj; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id u13-20020a170906408d00b007c17d93ca62si4795937ejj.971.2022.12.21.22.14.44; Wed, 21 Dec 2022 22:15:07 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=XisQSdIj; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235174AbiLVGGe (ORCPT + 99 others); Thu, 22 Dec 2022 01:06:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235043AbiLVGGM (ORCPT ); Thu, 22 Dec 2022 01:06:12 -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 DE38B1C93F for ; Wed, 21 Dec 2022 22:05:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1671689106; 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=iq4cHvbMQpVcmBqe5fyUmrngiKVykMmjcTZb1s9VM+M=; b=XisQSdIjVpfRAH0vj57/2guOh0iUndxVGfbCROpTSCm3ZGmGCql2UWF6NUsnEuPBFkb31f 1ktkaJgZRwEUyguCfmB4Y4zYFAiwz0dHK5+h/tklkkfOfZpaQUs1vG9veV7kY7LQa0ICdm WWWKt+B3uIszyhtd99gT5NH+nwbHVlI= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-456-A0Z1sWhoPamSGCtY6shq7w-1; Thu, 22 Dec 2022 01:05:02 -0500 X-MC-Unique: A0Z1sWhoPamSGCtY6shq7w-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7C82F38149BC; Thu, 22 Dec 2022 06:05:02 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-179.pek2.redhat.com [10.72.13.179]) by smtp.corp.redhat.com (Postfix) with ESMTP id CC707112132C; Thu, 22 Dec 2022 06:04:55 +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: [RFC PATCH 4/4] virtio-net: sleep instead of busy waiting for cvq command Date: Thu, 22 Dec 2022 14:04:27 +0800 Message-Id: <20221222060427.21626-5-jasowang@redhat.com> In-Reply-To: <20221222060427.21626-1-jasowang@redhat.com> References: <20221222060427.21626-1-jasowang@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1752893706697797202?= X-GMAIL-MSGID: =?utf-8?q?1752893706697797202?= 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 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 a signal. Signed-off-by: Jason Wang --- drivers/net/virtio_net.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 8225496ccb1e..69173049371f 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; @@ -2024,12 +2030,7 @@ 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(); + virtqueue_wait_for_used(vi->cvq, &tmp); return vi->ctrl->status == VIRTIO_NET_OK; } @@ -3524,7 +3525,7 @@ 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"; }