From nobody Tue Apr 30 18:01:42 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1495190102782991.2590878713453; Fri, 19 May 2017 03:35:02 -0700 (PDT) Received: from localhost ([::1]:57679 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dBfFM-0002HL-LZ for importer@patchew.org; Fri, 19 May 2017 06:35:01 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33833) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dBfDQ-00013Z-7s for qemu-devel@nongnu.org; Fri, 19 May 2017 06:33:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dBfDP-00080I-Dx for qemu-devel@nongnu.org; Fri, 19 May 2017 06:33:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54864) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dBfDL-0007z0-DF; Fri, 19 May 2017 06:32:55 -0400 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 5351C7AE81; Fri, 19 May 2017 10:32:54 +0000 (UTC) Received: from localhost (ovpn-117-50.ams2.redhat.com [10.36.117.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id DDF9618688; Fri, 19 May 2017 10:32:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 5351C7AE81 Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=stefanha@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 5351C7AE81 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Date: Fri, 19 May 2017 11:32:44 +0100 Message-Id: <20170519103247.4405-2-stefanha@redhat.com> In-Reply-To: <20170519103247.4405-1-stefanha@redhat.com> References: <20170519103247.4405-1-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 [10.5.110.25]); Fri, 19 May 2017 10:32:54 +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 v2 1/4] block: count bdrv_co_rw_vmstate() requests 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 , Paolo Bonzini , Fam Zheng , Stefan Hajnoczi , qemu-block@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Call bdrv_inc/dec_in_flight() for vmstate reads/writes. This seems unnecessary at first glance because vmstate reads/writes are done synchronously while the guest is stopped. But we need the bdrv_wakeup() in bdrv_dec_in_flight() so the main loop sees request completion. Besides, it's cleaner to count vmstate reads/writes like ordinary read/write requests. The bdrv_wakeup() partially fixes a 'savevm' hang with -object iothread. Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake Reviewed-by: Paolo Bonzini --- block/io.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/block/io.c b/block/io.c index fdd7485..cc56e90 100644 --- a/block/io.c +++ b/block/io.c @@ -1988,17 +1988,24 @@ bdrv_co_rw_vmstate(BlockDriverState *bs, QEMUIOVect= or *qiov, int64_t pos, bool is_read) { BlockDriver *drv =3D bs->drv; + int ret =3D -ENOTSUP; + + bdrv_inc_in_flight(bs); =20 if (!drv) { - return -ENOMEDIUM; + ret =3D -ENOMEDIUM; } else if (drv->bdrv_load_vmstate) { - return is_read ? drv->bdrv_load_vmstate(bs, qiov, pos) - : drv->bdrv_save_vmstate(bs, qiov, pos); + if (is_read) { + ret =3D drv->bdrv_load_vmstate(bs, qiov, pos); + } else { + ret =3D drv->bdrv_save_vmstate(bs, qiov, pos); + } } else if (bs->file) { - return bdrv_co_rw_vmstate(bs->file->bs, qiov, pos, is_read); + ret =3D bdrv_co_rw_vmstate(bs->file->bs, qiov, pos, is_read); } =20 - return -ENOTSUP; + bdrv_dec_in_flight(bs); + return ret; } =20 static void coroutine_fn bdrv_co_rw_vmstate_entry(void *opaque) --=20 2.9.3 From nobody Tue Apr 30 18:01:42 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1495190403663851.4542893685551; Fri, 19 May 2017 03:40:03 -0700 (PDT) Received: from localhost ([::1]:57710 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dBfKD-0006fH-Um for importer@patchew.org; Fri, 19 May 2017 06:40:02 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33906) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dBfDW-000190-7E for qemu-devel@nongnu.org; Fri, 19 May 2017 06:33:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dBfDS-00081T-HV for qemu-devel@nongnu.org; Fri, 19 May 2017 06:33:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43210) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dBfDQ-00080Q-Gd; Fri, 19 May 2017 06:33:00 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7EEC9C056782; Fri, 19 May 2017 10:32:59 +0000 (UTC) Received: from localhost (ovpn-117-50.ams2.redhat.com [10.36.117.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id C2B51189EF; Fri, 19 May 2017 10:32:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 7EEC9C056782 Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx08.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=stefanha@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 7EEC9C056782 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Date: Fri, 19 May 2017 11:32:45 +0100 Message-Id: <20170519103247.4405-3-stefanha@redhat.com> In-Reply-To: <20170519103247.4405-1-stefanha@redhat.com> References: <20170519103247.4405-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Fri, 19 May 2017 10:32:59 +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 v2 2/4] block: use BDRV_POLL_WHILE() in bdrv_rw_vmstate() 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 , Paolo Bonzini , Fam Zheng , Stefan Hajnoczi , qemu-block@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Calling aio_poll() directly may have been fine previously, but this is the future, man! The difference between an aio_poll() loop and BDRV_POLL_WHILE() is that BDRV_POLL_WHILE() releases the AioContext around aio_poll(). This allows the IOThread to run fd handlers or BHs to complete the request. Failure to release the AioContext causes deadlocks. Using BDRV_POLL_WHILE() partially fixes a 'savevm' hang with -object iothread. Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake Reviewed-by: Paolo Bonzini --- block/io.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/block/io.c b/block/io.c index cc56e90..f0041cd 100644 --- a/block/io.c +++ b/block/io.c @@ -2031,9 +2031,7 @@ bdrv_rw_vmstate(BlockDriverState *bs, QEMUIOVector *q= iov, int64_t pos, Coroutine *co =3D qemu_coroutine_create(bdrv_co_rw_vmstate_entry, = &data); =20 bdrv_coroutine_enter(bs, co); - while (data.ret =3D=3D -EINPROGRESS) { - aio_poll(bdrv_get_aio_context(bs), true); - } + BDRV_POLL_WHILE(bs, data.ret =3D=3D -EINPROGRESS); return data.ret; } } --=20 2.9.3 From nobody Tue Apr 30 18:01:42 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 149519025588931.341221519409828; Fri, 19 May 2017 03:37:35 -0700 (PDT) Received: from localhost ([::1]:57694 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dBfHq-0004Zk-Ga for importer@patchew.org; Fri, 19 May 2017 06:37:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33921) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dBfDX-0001AI-Ls for qemu-devel@nongnu.org; Fri, 19 May 2017 06:33:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dBfDU-00081p-F7 for qemu-devel@nongnu.org; Fri, 19 May 2017 06:33:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47250) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dBfDS-000814-5t; Fri, 19 May 2017 06:33:02 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 275B33D95E; Fri, 19 May 2017 10:33:01 +0000 (UTC) Received: from localhost (ovpn-117-50.ams2.redhat.com [10.36.117.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id ADA4B5C7A2; Fri, 19 May 2017 10:33:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 275B33D95E Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=stefanha@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 275B33D95E From: Stefan Hajnoczi To: qemu-devel@nongnu.org Date: Fri, 19 May 2017 11:32:46 +0100 Message-Id: <20170519103247.4405-4-stefanha@redhat.com> In-Reply-To: <20170519103247.4405-1-stefanha@redhat.com> References: <20170519103247.4405-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Fri, 19 May 2017 10:33:01 +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 v2 3/4] migration: avoid recursive AioContext locking in save_vmstate() 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 , Paolo Bonzini , Fam Zheng , Stefan Hajnoczi , qemu-block@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" AioContext was designed to allow nested acquire/release calls. It uses a recursive mutex so callers don't need to worry about nesting...or so we thought. BDRV_POLL_WHILE() is used to wait for block I/O requests. It releases the AioContext temporarily around aio_poll(). This gives IOThreads a chance to acquire the AioContext to process I/O completions. It turns out that recursive locking and BDRV_POLL_WHILE() don't mix. BDRV_POLL_WHILE() only releases the AioContext once, so the IOThread will not be able to acquire the AioContext if it was acquired multiple times. Instead of trying to release AioContext n times in BDRV_POLL_WHILE(), this patch simply avoids nested locking in save_vmstate(). It's the simplest fix and we should step back to consider the big picture with all the recent changes to block layer threading. This patch is the final fix to solve 'savevm' hanging with -object iothread. Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake Reviewed-by: Paolo Bonzini --- migration/savevm.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/migration/savevm.c b/migration/savevm.c index f5e8194..3ca319f 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -2150,6 +2150,14 @@ int save_vmstate(const char *name, Error **errp) goto the_end; } =20 + /* The bdrv_all_create_snapshot() call that follows acquires the AioCo= ntext + * for itself. BDRV_POLL_WHILE() does not support nested locking beca= use + * it only releases the lock once. Therefore synchronous I/O will dea= dlock + * unless we release the AioContext before bdrv_all_create_snapshot(). + */ + aio_context_release(aio_context); + aio_context =3D NULL; + ret =3D bdrv_all_create_snapshot(sn, bs, vm_state_size, &bs); if (ret < 0) { error_setg(errp, "Error while creating snapshot on '%s'", @@ -2160,7 +2168,9 @@ int save_vmstate(const char *name, Error **errp) ret =3D 0; =20 the_end: - aio_context_release(aio_context); + if (aio_context) { + aio_context_release(aio_context); + } if (saved_vm_running) { vm_start(); } --=20 2.9.3 From nobody Tue Apr 30 18:01:42 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1495190376389702.1794125011253; Fri, 19 May 2017 03:39:36 -0700 (PDT) Received: from localhost ([::1]:57707 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dBfJm-0006HN-IN for importer@patchew.org; Fri, 19 May 2017 06:39:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33946) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dBfDZ-0001Cw-UH for qemu-devel@nongnu.org; Fri, 19 May 2017 06:33:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dBfDZ-00082w-2F for qemu-devel@nongnu.org; Fri, 19 May 2017 06:33:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37386) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dBfDW-00081z-2G; Fri, 19 May 2017 06:33:06 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0C8EF804F6; Fri, 19 May 2017 10:33:05 +0000 (UTC) Received: from localhost (ovpn-117-50.ams2.redhat.com [10.36.117.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id BB9DB5B83A; Fri, 19 May 2017 10:33:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 0C8EF804F6 Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=stefanha@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 0C8EF804F6 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Date: Fri, 19 May 2017 11:32:47 +0100 Message-Id: <20170519103247.4405-5-stefanha@redhat.com> In-Reply-To: <20170519103247.4405-1-stefanha@redhat.com> References: <20170519103247.4405-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 19 May 2017 10:33:05 +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 v2 4/4] migration: use bdrv_drain_all_begin/end() instead bdrv_drain_all() 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 , Paolo Bonzini , Fam Zheng , Stefan Hajnoczi , qemu-block@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" blk/bdrv_drain_all() only takes effect for a single instant and then resumes block jobs, guest devices, and other external clients like the NBD server. This can be handy when performing a synchronous drain before terminating the program, for example. Monitor commands usually need to quiesce I/O across an entire code region so blk/bdrv_drain_all() is not suitable. They must use bdrv_drain_all_begin/end() to mark the region. This prevents new I/O requests from slipping in or worse - block jobs completing and modifying the graph. I audited other blk/bdrv_drain_all() callers but did not find anything that needs a similar fix. This patch fixes the savevm/loadvm commands. Although I haven't encountered a read world issue this makes the code safer. Suggested-by: Kevin Wolf Signed-off-by: Stefan Hajnoczi --- migration/savevm.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/migration/savevm.c b/migration/savevm.c index 3ca319f..f134e48 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -2113,6 +2113,8 @@ int save_vmstate(const char *name, Error **errp) } vm_stop(RUN_STATE_SAVE_VM); =20 + bdrv_drain_all_begin(); + aio_context_acquire(aio_context); =20 memset(sn, 0, sizeof(*sn)); @@ -2171,6 +2173,9 @@ int save_vmstate(const char *name, Error **errp) if (aio_context) { aio_context_release(aio_context); } + + bdrv_drain_all_end(); + if (saved_vm_running) { vm_start(); } @@ -2279,7 +2284,7 @@ int load_vmstate(const char *name, Error **errp) } =20 /* Flush all IO requests so they don't interfere with the new state. = */ - bdrv_drain_all(); + bdrv_drain_all_begin(); =20 ret =3D bdrv_all_goto_snapshot(name, &bs); if (ret < 0) { @@ -2303,6 +2308,8 @@ int load_vmstate(const char *name, Error **errp) qemu_fclose(f); aio_context_release(aio_context); =20 + bdrv_drain_all_end(); + migration_incoming_state_destroy(); if (ret < 0) { error_setg(errp, "Error %d while loading VM state", ret); --=20 2.9.3