From patchwork Tue Dec 5 10:41:40 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 844683 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3yrdk61kpWz9tB7 for ; Tue, 5 Dec 2017 21:47:41 +1100 (AEDT) Received: from localhost ([::1]:47785 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eMAlH-0007IN-5H for incoming@patchwork.ozlabs.org; Tue, 05 Dec 2017 05:47:39 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54858) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eMAgJ-0002kb-5v for qemu-devel@nongnu.org; Tue, 05 Dec 2017 05:42:32 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eMAgI-0002lW-4p for qemu-devel@nongnu.org; Tue, 05 Dec 2017 05:42:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47032) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eMAgD-0002iN-JE; Tue, 05 Dec 2017 05:42:25 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B3B3713AA6; Tue, 5 Dec 2017 10:42:24 +0000 (UTC) Received: from localhost (ovpn-117-172.ams2.redhat.com [10.36.117.172]) by smtp.corp.redhat.com (Postfix) with ESMTP id 501C85DA67; Tue, 5 Dec 2017 10:42:24 +0000 (UTC) From: Stefan Hajnoczi To: Date: Tue, 5 Dec 2017 10:41:40 +0000 Message-Id: <20171205104141.28882-9-stefanha@redhat.com> In-Reply-To: <20171205104141.28882-1-stefanha@redhat.com> References: <20171205104141.28882-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Tue, 05 Dec 2017 10:42:24 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 8/9] blockdev: add x-blockdev-set-iothread testing command 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: Kevin Wolf , John Snow , Stefan Hajnoczi , qemu-block@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Currently there is no easy way for iotests to ensure that a BDS is bound to a particular IOThread. Normally the virtio-blk device calls blk_set_aio_context() when dataplane is enabled during guest driver initialization. This never happens in iotests since -machine accel=qtest means there is no guest activity (including device driver initialization). This patch adds a QMP command to explicitly assign IOThreads in test cases. See qapi/block-core.json for a description of the command. Signed-off-by: Stefan Hajnoczi --- qapi/block-core.json | 36 ++++++++++++++++++++++++++++++++++++ blockdev.c | 41 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 77 insertions(+) diff --git a/qapi/block-core.json b/qapi/block-core.json index dd763dcf87..d892cc9c78 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -3949,3 +3949,39 @@ 'data' : { 'parent': 'str', '*child': 'str', '*node': 'str' } } + +## +# @x-blockdev-set-iothread: +# +# Move @node and its children into the @iothread. If @iothread is empty then +# move @node and its children into the main loop. +# +# The node must not be attached to a BlockBackend. +# +# @node-name: the name of the block driver node +# +# @iothread: the name of the IOThread object +# +# Note: this command is experimental and intended for test cases that need +# control over IOThreads only. +# +# Since: 2.12 +# +# Example: +# +# 1. Move a node into an IOThread +# -> { "execute": "x-blockdev-set-iothread", +# "arguments": { "node-name": "disk1", +# "iothread": "iothread0" } } +# <- { "return": {} } +# +# 2. Move a node into the main loop +# -> { "execute": "x-blockdev-set-iothread", +# "arguments": { "node-name": "disk1", +# "iothread": "" } } +# <- { "return": {} } +# +## +{ 'command': 'x-blockdev-set-iothread', + 'data' : { 'node-name': 'str', + 'iothread': 'str' } } diff --git a/blockdev.c b/blockdev.c index e865ae4873..d21faa0b41 100644 --- a/blockdev.c +++ b/blockdev.c @@ -45,6 +45,7 @@ #include "qapi/qmp/qerror.h" #include "qapi/qobject-output-visitor.h" #include "sysemu/sysemu.h" +#include "sysemu/iothread.h" #include "block/block_int.h" #include "qmp-commands.h" #include "block/trace.h" @@ -4129,6 +4130,46 @@ BlockJobInfoList *qmp_query_block_jobs(Error **errp) return head; } +void qmp_x_blockdev_set_iothread(const char *node_name, const char *iothread, + Error **errp) +{ + AioContext *old_context; + AioContext *new_context; + BlockDriverState *bs; + + bs = bdrv_find_node(node_name); + if (!bs) { + error_setg(errp, "Cannot find node %s", node_name); + return; + } + + /* If we want to allow more extreme test scenarios this guard could be + * removed. For now it protects against accidents. */ + if (bdrv_has_blk(bs)) { + error_setg(errp, "Node %s is in use", node_name); + return; + } + + if (iothread[0]) { + IOThread *obj = iothread_by_id(iothread); + if (!obj) { + error_setg(errp, "Cannot find iothread %s", iothread); + return; + } + + new_context = iothread_get_aio_context(obj); + } else { + new_context = qemu_get_aio_context(); + } + + old_context = bdrv_get_aio_context(bs); + aio_context_acquire(old_context); + + bdrv_set_aio_context(bs, new_context); + + aio_context_release(old_context); +} + QemuOptsList qemu_common_drive_opts = { .name = "drive", .head = QTAILQ_HEAD_INITIALIZER(qemu_common_drive_opts.head),