From patchwork Mon Feb 18 16:18:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 10818429 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CC1056CB for ; Mon, 18 Feb 2019 16:21:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B81CE2B0E3 for ; Mon, 18 Feb 2019 16:21:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B65DE2B2EB; Mon, 18 Feb 2019 16:21:43 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 69B782B0E3 for ; Mon, 18 Feb 2019 16:21:43 +0000 (UTC) Received: from localhost ([127.0.0.1]:33039 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gvlfq-0006r7-BG for patchwork-qemu-devel@patchwork.kernel.org; Mon, 18 Feb 2019 11:21:42 -0500 Received: from eggs.gnu.org ([209.51.188.92]:34721) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gvldO-0006GF-Sm for qemu-devel@nongnu.org; Mon, 18 Feb 2019 11:19:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gvldK-0002Mo-MP for qemu-devel@nongnu.org; Mon, 18 Feb 2019 11:19:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37442) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gvldH-0002DE-GJ; Mon, 18 Feb 2019 11:19:03 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 404425A49; Mon, 18 Feb 2019 16:18:49 +0000 (UTC) Received: from dhcp-200-176.str.redhat.com (dhcp-200-176.str.redhat.com [10.33.200.176]) by smtp.corp.redhat.com (Postfix) with ESMTP id A555D5D70E; Mon, 18 Feb 2019 16:18:47 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Date: Mon, 18 Feb 2019 17:18:12 +0100 Message-Id: <20190218161822.3573-3-kwolf@redhat.com> In-Reply-To: <20190218161822.3573-1-kwolf@redhat.com> References: <20190218161822.3573-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Mon, 18 Feb 2019 16:18:49 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 02/12] virtio-blk: Increase in_flight for request restart BH X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP virtio_blk_dma_restart_bh() submits new requests, so in order to make sure that these requests are not started inside a drained section of the attached BlockBackend, we need to make sure that draining the BlockBackend waits for the BH to be executed. This BH is still questionable because its scheduled in the main thread instead of the configured iothread. Leave a FIXME comment for this. But with this fix, enabling the data plane at least waits for these requests (in bdrv_set_aio_context()) instead of changing the AioContext under their feet and making them run in the wrong thread, causing crashes and failures (e.g. due to missing locking). Signed-off-by: Kevin Wolf --- hw/block/virtio-blk.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index cf7f47eaba..e11e6e45d0 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -675,6 +675,7 @@ static void virtio_blk_dma_restart_bh(void *opaque) if (mrb.num_reqs) { virtio_blk_submit_multireq(s->blk, &mrb); } + blk_dec_in_flight(s->conf.conf.blk); aio_context_release(blk_get_aio_context(s->conf.conf.blk)); } @@ -688,8 +689,11 @@ static void virtio_blk_dma_restart_cb(void *opaque, int running, } if (!s->bh) { + /* FIXME The data plane is not started yet, so these requests are + * processed in the main thread. */ s->bh = aio_bh_new(blk_get_aio_context(s->conf.conf.blk), virtio_blk_dma_restart_bh, s); + blk_inc_in_flight(s->conf.conf.blk); qemu_bh_schedule(s->bh); } }