From mboxrd@z Thu Jan 1 00:00:00 1970 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 D2F37C61D97 for ; Sun, 29 Jan 2023 07:26:24 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pM24h-0002p0-Pf; Sun, 29 Jan 2023 02:26:03 -0500 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 1pM24f-0002or-Qj for qemu-devel@nongnu.org; Sun, 29 Jan 2023 02:26:01 -0500 Received: from out30-56.freemail.mail.aliyun.com ([115.124.30.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pM24d-0006ru-5V for qemu-devel@nongnu.org; Sun, 29 Jan 2023 02:26:01 -0500 X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R531e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=ay29a033018045192; MF=xuanzhuo@linux.alibaba.com; NM=1; PH=DS; RN=3; SR=0; TI=SMTPD_---0VaJisu1_1674977147; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0VaJisu1_1674977147) by smtp.aliyun-inc.com; Sun, 29 Jan 2023 15:25:47 +0800 Message-ID: <1674976516.577517-1-xuanzhuo@linux.alibaba.com> Subject: Re: [PATCH v1 1/2] virtio: struct VirtQueue introduce reset Date: Sun, 29 Jan 2023 15:15:16 +0800 From: Xuan Zhuo To: "Michael S. Tsirkin" Cc: qemu-devel@nongnu.org, Jason Wang References: <20230129025150.119972-1-xuanzhuo@linux.alibaba.com> <20230129025150.119972-2-xuanzhuo@linux.alibaba.com> <20230129020903-mutt-send-email-mst@kernel.org> In-Reply-To: <20230129020903-mutt-send-email-mst@kernel.org> Received-SPF: pass client-ip=115.124.30.56; envelope-from=xuanzhuo@linux.alibaba.com; helo=out30-56.freemail.mail.aliyun.com X-Spam_score_int: -98 X-Spam_score: -9.9 X-Spam_bar: --------- X-Spam_report: (-9.9 / 5.0 requ) BAYES_00=-1.9, ENV_AND_HDR_SPF_MATCH=-0.5, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, UNPARSEABLE_RELAY=0.001, USER_IN_DEF_SPF_WL=-7.5 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 On Sun, 29 Jan 2023 02:12:36 -0500, "Michael S. Tsirkin" wrote: > > subject seems wrong. Will fix. > > On Sun, Jan 29, 2023 at 10:51:49AM +0800, Xuan Zhuo wrote: > > In the current design, we stop the device from operating on the vring > > during per-queue reset by resetting the structure VirtQueue. > > > > But before the reset operation, when recycling some resources, we should > > stop referencing new vring resources. For example, when recycling > > virtio-net's asynchronous sending resources, virtio-net should be able > > to perceive that the current queue is in the per-queue reset state, and > > stop sending new packets from the tx queue. > > > > Signed-off-by: Xuan Zhuo > > --- > > hw/virtio/virtio.c | 15 +++++++++++++++ > > include/hw/virtio/virtio.h | 1 + > > 2 files changed, 16 insertions(+) > > > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > > index f35178f5fc..c954f2a2b3 100644 > > --- a/hw/virtio/virtio.c > > +++ b/hw/virtio/virtio.c > > @@ -142,6 +142,8 @@ struct VirtQueue > > /* Notification enabled? */ > > bool notification; > > > > + bool disabled_by_reset; > > + > > uint16_t queue_index; > > > > unsigned int inuse; > > @@ -2079,6 +2081,12 @@ void virtio_queue_reset(VirtIODevice *vdev, uint32_t queue_index) > > { > > VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev); > > > > + /* > > + * Mark this queue is per-queue reset status. The device should release the > > + * references of the vring, and not refer more new vring item. > > items Will fix. > > > + */ > > + vdev->vq[queue_index].disabled_by_reset = true; > > + > > if (k->queue_reset) { > > k->queue_reset(vdev, queue_index); > > } > > can we set this after calling queue_reset? For symmetry with enable. In fact, queue_reset() will check it. > > > @@ -2102,11 +2110,18 @@ void virtio_queue_enable(VirtIODevice *vdev, uint32_t queue_index) > > } > > */ > > > > + vdev->vq[queue_index].disabled_by_reset = false; > > + > > if (k->queue_enable) { > > k->queue_enable(vdev, queue_index); > > } > > } > > > > +bool virtio_queue_reset_state(VirtQueue *vq) > > +{ > > + return vq->disabled_by_reset; > > +} > > + > > void virtio_reset(void *opaque) > > { > > VirtIODevice *vdev = opaque; > > diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > > index 77c6c55929..00e91af7c4 100644 > > --- a/include/hw/virtio/virtio.h > > +++ b/include/hw/virtio/virtio.h > > @@ -319,6 +319,7 @@ int virtio_set_status(VirtIODevice *vdev, uint8_t val); > > void virtio_reset(void *opaque); > > void virtio_queue_reset(VirtIODevice *vdev, uint32_t queue_index); > > void virtio_queue_enable(VirtIODevice *vdev, uint32_t queue_index); > > +bool virtio_queue_reset_state(VirtQueue *vq); > > void virtio_update_irq(VirtIODevice *vdev); > > int virtio_set_features(VirtIODevice *vdev, uint64_t val); > > OK I guess ... what about migration. This state won't be > set correctly will it? I think it has no effect. After the reset, there is actually no state. We can migrate. The current variable is only used by ->queue_reset(). Thanks. > > > > > > -- > > 2.32.0.3.g01195cf9f >