From patchwork Thu Jan 30 10:08:30 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej S. Szmigiero" X-Patchwork-Id: 13954430 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id BF1B8C0218A for ; Thu, 30 Jan 2025 10:10:53 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tdRUs-0002dO-DK; Thu, 30 Jan 2025 05:10:06 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tdRUp-0002SF-Ev for qemu-devel@nongnu.org; Thu, 30 Jan 2025 05:10:03 -0500 Received: from vps-ovh.mhejs.net ([145.239.82.108]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tdRUn-00074W-Mb for qemu-devel@nongnu.org; Thu, 30 Jan 2025 05:10:03 -0500 Received: from MUA by vps-ovh.mhejs.net with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.98) (envelope-from ) id 1tdRUj-00000006Txh-1BNQ; Thu, 30 Jan 2025 11:09:57 +0100 From: "Maciej S. Szmigiero" To: Peter Xu , Fabiano Rosas Cc: Alex Williamson , =?utf-8?q?C=C3=A9dric_Le_G?= =?utf-8?q?oater?= , Eric Blake , Markus Armbruster , =?utf-8?q?Daniel_P_=2E_Berrang=C3=A9?= , Avihai Horon , Joao Martins , qemu-devel@nongnu.org Subject: [PATCH v4 09/33] migration: postcopy_ram_listen_thread() needs to take BQL for some calls Date: Thu, 30 Jan 2025 11:08:30 +0100 Message-ID: <139bf266dbd1e25a1e5a050ecb82e3e59120d705.1738171076.git.maciej.szmigiero@oracle.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=145.239.82.108; envelope-from=mhej@vps-ovh.mhejs.net; helo=vps-ovh.mhejs.net X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.037, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: "Maciej S. Szmigiero" postcopy_ram_listen_thread() is a free running thread, so it needs to take BQL around function calls to migration methods requiring BQL. qemu_loadvm_state_main() needs BQL held since it ultimately calls "load_state" SaveVMHandlers. migration_incoming_state_destroy() needs BQL held since it ultimately calls "load_cleanup" SaveVMHandlers. Signed-off-by: Maciej S. Szmigiero --- migration/savevm.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/migration/savevm.c b/migration/savevm.c index b0b74140daea..0ceea9638cc1 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -2013,7 +2013,9 @@ static void *postcopy_ram_listen_thread(void *opaque) * in qemu_file, and thus we must be blocking now. */ qemu_file_set_blocking(f, true); + bql_lock(); load_res = qemu_loadvm_state_main(f, mis); + bql_unlock(); /* * This is tricky, but, mis->from_src_file can change after it @@ -2073,7 +2075,9 @@ static void *postcopy_ram_listen_thread(void *opaque) * (If something broke then qemu will have to exit anyway since it's * got a bad migration state). */ + bql_lock(); migration_incoming_state_destroy(); + bql_unlock(); rcu_unregister_thread(); mis->have_listen_thread = false;