From patchwork Wed May 20 15:53:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dima Stepanov X-Patchwork-Id: 282264 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4DC43C433DF for ; Wed, 20 May 2020 15:55:23 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 0F3C020671 for ; Wed, 20 May 2020 15:55:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=yandex-team.ru header.i=@yandex-team.ru header.b="0Jvdd1OK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0F3C020671 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=yandex-team.ru Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55526 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jbR3y-0001sg-7Q for qemu-devel@archiver.kernel.org; Wed, 20 May 2020 11:55:22 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42226) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jbR2m-0008Di-GJ; Wed, 20 May 2020 11:54:08 -0400 Received: from forwardcorp1o.mail.yandex.net ([2a02:6b8:0:1a2d::193]:44198) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jbR2k-0001IJ-MA; Wed, 20 May 2020 11:54:08 -0400 Received: from mxbackcorp1j.mail.yandex.net (mxbackcorp1j.mail.yandex.net [IPv6:2a02:6b8:0:1619::162]) by forwardcorp1o.mail.yandex.net (Yandex) with ESMTP id D3E0C2E15FD; Wed, 20 May 2020 18:54:02 +0300 (MSK) Received: from vla5-58875c36c028.qloud-c.yandex.net (vla5-58875c36c028.qloud-c.yandex.net [2a02:6b8:c18:340b:0:640:5887:5c36]) by mxbackcorp1j.mail.yandex.net (mxbackcorp/Yandex) with ESMTP id i6WipSSTU2-s0TSmWHo; Wed, 20 May 2020 18:54:02 +0300 Precedence: bulk DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1589990042; bh=+SjeKv7JofGN47sm5ZgJS2qgyS6IMRcoqy6Nk2Fpuz0=; h=In-Reply-To:In-Reply-To:Message-Id:References:References:Date: Subject:To:From:Cc; b=0Jvdd1OK6fcwj+R8JIxxtfPEvxroY68k0ltjob4e6EambsqbfrCMFJtjnqVVjtvyS Wl6W/QsrwIhpijSENdfpOaHqIAPZqIZYeP9Mmg879FhwWhv/TOVgPdxswYUt8UDbPl 3CU9T3CaJZO9IEG1OU02IdS5NVcI3UqyBlTHzDZ4= Authentication-Results: mxbackcorp1j.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Received: from dynamic-vpn.dhcp.yndx.net (dynamic-vpn.dhcp.yndx.net [2a02:6b8:b081:1221::1:11]) by vla5-58875c36c028.qloud-c.yandex.net (smtpcorp/Yandex) with ESMTPSA id wLIWnjIOwO-s0Xe43DN; Wed, 20 May 2020 18:54:00 +0300 (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (Client certificate not present) From: Dima Stepanov To: qemu-devel@nongnu.org Subject: [PATCH v3 2/2] vhost-user-blk: delay vhost_user_blk_disconnect Date: Wed, 20 May 2020 18:53:13 +0300 Message-Id: <0dfb37f8728aba26c8d6c117018332a5b7dc9b56.1589989075.git.dimastep@yandex-team.ru> X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: Received-SPF: pass client-ip=2a02:6b8:0:1a2d::193; envelope-from=dimastep@yandex-team.ru; helo=forwardcorp1o.mail.yandex.net X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, qemu-block@nongnu.org, mst@redhat.com, jasowang@redhat.com, dgilbert@redhat.com, mreitz@redhat.com, fengli@smartx.com, yc-core@yandex-team.ru, marcandre.lureau@redhat.com, pbonzini@redhat.com, raphael.norwitz@nutanix.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" A socket write during vhost-user communication may trigger a disconnect event, calling vhost_user_blk_disconnect() and clearing all the vhost_dev structures holding data that vhost-user functions expect to remain valid to roll back initialization correctly. Delay the cleanup to keep vhost_dev structure valid. There are two possible states to handle: 1. RUN_STATE_PRELAUNCH: skip bh oneshot call and perform disconnect in the caller routine. 2. RUN_STATE_RUNNING: delay by using bh BH changes are based on the similar changes for the vhost-user-net device: commit e7c83a885f865128ae3cf1946f8cb538b63cbfba "vhost-user: delay vhost_user_stop" Signed-off-by: Dima Stepanov --- hw/block/vhost-user-blk.c | 49 +++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 43 insertions(+), 6 deletions(-) diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c index 9d8c0b3..447fc9c 100644 --- a/hw/block/vhost-user-blk.c +++ b/hw/block/vhost-user-blk.c @@ -337,11 +337,6 @@ static void vhost_user_blk_disconnect(DeviceState *dev) VirtIODevice *vdev = VIRTIO_DEVICE(dev); VHostUserBlk *s = VHOST_USER_BLK(vdev); - if (!s->connected) { - return; - } - s->connected = false; - if (s->dev.started) { vhost_user_blk_stop(vdev); } @@ -349,6 +344,19 @@ static void vhost_user_blk_disconnect(DeviceState *dev) vhost_dev_cleanup(&s->dev); } +static void vhost_user_blk_event(void *opaque, QEMUChrEvent event); + +static void vhost_user_blk_chr_closed_bh(void *opaque) +{ + DeviceState *dev = opaque; + VirtIODevice *vdev = VIRTIO_DEVICE(dev); + VHostUserBlk *s = VHOST_USER_BLK(vdev); + + vhost_user_blk_disconnect(dev); + qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, vhost_user_blk_event, + NULL, opaque, NULL, true); +} + static void vhost_user_blk_event(void *opaque, QEMUChrEvent event) { DeviceState *dev = opaque; @@ -363,7 +371,28 @@ static void vhost_user_blk_event(void *opaque, QEMUChrEvent event) } break; case CHR_EVENT_CLOSED: - vhost_user_blk_disconnect(dev); + /* + * A close event may happen during a read/write, but vhost + * code assumes the vhost_dev remains setup, so delay the + * stop & clear. There are two possible paths to hit this + * disconnect event: + * 1. When VM is in the RUN_STATE_PRELAUNCH state. The + * vhost_user_blk_device_realize() is a caller. + * 2. In tha main loop phase after VM start. + * + * For p2 the disconnect event will be delayed. We can't + * do the same for p1, because we are not running the loop + * at this moment. So just skip this step and perform + * disconnect in the caller function. + */ + if (s->connected && runstate_is_running()) { + AioContext *ctx = qemu_get_current_aio_context(); + + qemu_chr_fe_set_handlers(&s->chardev, NULL, NULL, NULL, NULL, + NULL, NULL, false); + aio_bh_schedule_oneshot(ctx, vhost_user_blk_chr_closed_bh, opaque); + } + s->connected = false; break; case CHR_EVENT_BREAK: case CHR_EVENT_MUX_IN: @@ -428,6 +457,14 @@ reconnect: ret = vhost_dev_get_config(&s->dev, (uint8_t *)&s->blkcfg, sizeof(struct virtio_blk_config)); + if (!s->connected) { + /* + * Perform disconnect before making reconnect. More detailed + * comment why it was delayed is in the vhost_user_blk_event() + * routine. + */ + vhost_user_blk_disconnect(dev); + } if (ret < 0) { error_report("vhost-user-blk: get block config failed"); goto reconnect;