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 548EAC7EE23 for ; Tue, 30 May 2023 16:36:53 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1q42Ip-00023n-Jm; Tue, 30 May 2023 12:34:31 -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 1q42Hh-0006wv-2u for qemu-devel@nongnu.org; Tue, 30 May 2023 12:33:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1q42He-0008TY-NM for qemu-devel@nongnu.org; Tue, 30 May 2023 12:33:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1685464396; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=123E95yY9EoHHxjf4VYk1zc9vgfUknZ60ThDYikdDPw=; b=JL2b5facbK3g+qe7HgeAcsR0/cAD+yLYuywVu+0Fz5wdmzaVctb/V6rZSf7AAcG35GgDfA aMI9III8vDGpAzopLio2NbARd1uZwkqRCWytTuQI9UqKq38gib0t8JrIxDFigrDWYWzw/p FeGLj4yVdIb9Z2tBIAmBqcx/3xGcHsc= 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-31-2ioook0AOWCwImXyr8BJ4g-1; Tue, 30 May 2023 12:33:14 -0400 X-MC-Unique: 2ioook0AOWCwImXyr8BJ4g-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 919FC3C17C62; Tue, 30 May 2023 16:33:14 +0000 (UTC) Received: from merkur.redhat.com (unknown [10.39.194.4]) by smtp.corp.redhat.com (Postfix) with ESMTP id D84CEC154D2; Tue, 30 May 2023 16:33:13 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, richard.henderson@linaro.org, qemu-devel@nongnu.org Subject: [PULL 29/32] virtio-blk: implement BlockDevOps->drained_begin() Date: Tue, 30 May 2023 18:32:36 +0200 Message-Id: <20230530163239.576632-30-kwolf@redhat.com> In-Reply-To: <20230530163239.576632-1-kwolf@redhat.com> References: <20230530163239.576632-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.129.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.167, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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: Stefan Hajnoczi Detach ioeventfds during drained sections to stop I/O submission from the guest. virtio-blk is no longer reliant on aio_disable_external() after this patch. This will allow us to remove the aio_disable_external() API once all other code that relies on it is converted. Take extra care to avoid attaching/detaching ioeventfds if the data plane is started/stopped during a drained section. This should be rare, but maybe the mirror block job can trigger it. Signed-off-by: Stefan Hajnoczi Message-Id: <20230516190238.8401-18-stefanha@redhat.com> Signed-off-by: Kevin Wolf --- hw/block/dataplane/virtio-blk.c | 16 ++++++++------ hw/block/virtio-blk.c | 38 ++++++++++++++++++++++++++++++++- 2 files changed, 47 insertions(+), 7 deletions(-) diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c index 4f5c7cd55f..b90456c08c 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -246,13 +246,15 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev) } /* Get this show started by hooking up our callbacks */ - aio_context_acquire(s->ctx); - for (i = 0; i < nvqs; i++) { - VirtQueue *vq = virtio_get_queue(s->vdev, i); + if (!blk_in_drain(s->conf->conf.blk)) { + aio_context_acquire(s->ctx); + for (i = 0; i < nvqs; i++) { + VirtQueue *vq = virtio_get_queue(s->vdev, i); - virtio_queue_aio_attach_host_notifier(vq, s->ctx); + virtio_queue_aio_attach_host_notifier(vq, s->ctx); + } + aio_context_release(s->ctx); } - aio_context_release(s->ctx); return 0; fail_aio_context: @@ -322,7 +324,9 @@ void virtio_blk_data_plane_stop(VirtIODevice *vdev) s->stopping = true; trace_virtio_blk_data_plane_stop(s); - aio_wait_bh_oneshot(s->ctx, virtio_blk_data_plane_stop_bh, s); + if (!blk_in_drain(s->conf->conf.blk)) { + aio_wait_bh_oneshot(s->ctx, virtio_blk_data_plane_stop_bh, s); + } aio_context_acquire(s->ctx); diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 8f65ea4659..4ca66b5860 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -1506,8 +1506,44 @@ static void virtio_blk_resize(void *opaque) aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev); } +/* Suspend virtqueue ioeventfd processing during drain */ +static void virtio_blk_drained_begin(void *opaque) +{ + VirtIOBlock *s = opaque; + VirtIODevice *vdev = VIRTIO_DEVICE(opaque); + AioContext *ctx = blk_get_aio_context(s->conf.conf.blk); + + if (!s->dataplane || !s->dataplane_started) { + return; + } + + for (uint16_t i = 0; i < s->conf.num_queues; i++) { + VirtQueue *vq = virtio_get_queue(vdev, i); + virtio_queue_aio_detach_host_notifier(vq, ctx); + } +} + +/* Resume virtqueue ioeventfd processing after drain */ +static void virtio_blk_drained_end(void *opaque) +{ + VirtIOBlock *s = opaque; + VirtIODevice *vdev = VIRTIO_DEVICE(opaque); + AioContext *ctx = blk_get_aio_context(s->conf.conf.blk); + + if (!s->dataplane || !s->dataplane_started) { + return; + } + + for (uint16_t i = 0; i < s->conf.num_queues; i++) { + VirtQueue *vq = virtio_get_queue(vdev, i); + virtio_queue_aio_attach_host_notifier(vq, ctx); + } +} + static const BlockDevOps virtio_block_ops = { - .resize_cb = virtio_blk_resize, + .resize_cb = virtio_blk_resize, + .drained_begin = virtio_blk_drained_begin, + .drained_end = virtio_blk_drained_end, }; static void virtio_blk_device_realize(DeviceState *dev, Error **errp) -- 2.40.1