From patchwork Fri Feb 12 06:39:34 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Denis V. Lunev" X-Patchwork-Id: 582099 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org 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 037EB140B04 for ; Fri, 12 Feb 2016 17:40:15 +1100 (AEDT) Received: from localhost ([::1]:56976 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aU7On-0005Mg-5J for incoming@patchwork.ozlabs.org; Fri, 12 Feb 2016 01:40:13 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57837) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aU7OR-0004jZ-9u for qemu-devel@nongnu.org; Fri, 12 Feb 2016 01:39:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aU7OM-000561-Ay for qemu-devel@nongnu.org; Fri, 12 Feb 2016 01:39:51 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:23222 helo=relay.sw.ru) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aU7OL-00055a-V9 for qemu-devel@nongnu.org; Fri, 12 Feb 2016 01:39:46 -0500 Received: from irbis.sw.ru ([10.30.2.139]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id u1C4upd7023925; Fri, 12 Feb 2016 07:56:56 +0300 (MSK) From: "Denis V. Lunev" To: Date: Fri, 12 Feb 2016 09:39:34 +0300 Message-Id: <1455259174-3384-3-git-send-email-den@openvz.org> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1455259174-3384-1-git-send-email-den@openvz.org> References: <1455259174-3384-1-git-send-email-den@openvz.org> X-detected-operating-system: by eggs.gnu.org: OpenBSD 3.x X-Received-From: 195.214.232.25 Cc: Amit Shah , "Denis V. Lunev" , Juan Quintela , qemu-devel@nongnu.org, Paolo Bonzini Subject: [Qemu-devel] [PATCH 2/2] migration: move bdrv_invalidate_cache_all of of coroutine context X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org There is a possibility to hit an assert in qcow2_get_specific_info that s->qcow_version is undefined. This happens when VM in starting from suspended state, i.e. it processes incoming migration, and in the same time 'info block' is called. The problem is that qcow2_invalidate_cache() closes the image and memset()s BDRVQcowState in the middle. The patch moves processing of bdrv_invalidate_cache_all out of coroutine context for postcopy migration to avoid that. This function is called with the following stack: process_incoming_migration_co qemu_loadvm_state qemu_loadvm_state_main loadvm_process_command loadvm_postcopy_handle_run Signed-off-by: Denis V. Lunev CC: Paolo Bonzini CC: Juan Quintela CC: Amit Shah Tested-by: Dr. David Alan Gilbert --- migration/savevm.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/migration/savevm.c b/migration/savevm.c index 94f2894..8415fd9 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1496,18 +1496,10 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis) return 0; } -/* After all discards we can start running and asking for pages */ -static int loadvm_postcopy_handle_run(MigrationIncomingState *mis) +static void loadvm_postcopy_handle_run_bh(void *opaque) { - PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_RUNNING); Error *local_err = NULL; - trace_loadvm_postcopy_handle_run(); - if (ps != POSTCOPY_INCOMING_LISTENING) { - error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps); - return -1; - } - /* TODO we should move all of this lot into postcopy_ram.c or a shared code * in migration.c */ @@ -1519,7 +1511,6 @@ static int loadvm_postcopy_handle_run(MigrationIncomingState *mis) bdrv_invalidate_cache_all(&local_err); if (local_err) { error_report_err(local_err); - return -1; } trace_loadvm_postcopy_handle_run_cpu_sync(); @@ -1534,6 +1525,22 @@ static int loadvm_postcopy_handle_run(MigrationIncomingState *mis) /* leave it paused and let management decide when to start the CPU */ runstate_set(RUN_STATE_PAUSED); } +} + +/* After all discards we can start running and asking for pages */ +static int loadvm_postcopy_handle_run(MigrationIncomingState *mis) +{ + PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_RUNNING); + QEMUBH *bh; + + trace_loadvm_postcopy_handle_run(); + if (ps != POSTCOPY_INCOMING_LISTENING) { + error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps); + return -1; + } + + bh = qemu_bh_new(loadvm_postcopy_handle_run_bh, NULL); + qemu_bh_schedule(bh); /* We need to finish reading the stream from the package * and also stop reading anything more from the stream that loaded the