From patchwork Tue Jun 18 16:12:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej S. Szmigiero" X-Patchwork-Id: 13702688 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 264A6C27C4F for ; Tue, 18 Jun 2024 16:13:59 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sJbSX-00030f-VH; Tue, 18 Jun 2024 12:13:25 -0400 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 1sJbSW-0002zr-An for qemu-devel@nongnu.org; Tue, 18 Jun 2024 12:13:24 -0400 Received: from vps-vb.mhejs.net ([37.28.154.113]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sJbSU-0000qR-OO for qemu-devel@nongnu.org; Tue, 18 Jun 2024 12:13:24 -0400 Received: from MUA by vps-vb.mhejs.net with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sJbSH-0001bF-Ao; Tue, 18 Jun 2024 18:13:09 +0200 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 v1 04/13] migration: Add save_live_complete_precopy_{begin, end} handlers Date: Tue, 18 Jun 2024 18:12:22 +0200 Message-ID: X-Mailer: git-send-email 2.45.1 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=37.28.154.113; envelope-from=mail@maciej.szmigiero.name; helo=vps-vb.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, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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" These SaveVMHandlers allow device to provide its own asynchronous transmission of the remaining data at the end of a precopy phase. In this use case the save_live_complete_precopy_begin handler is supposed to start such transmission (for example, by launching appropriate threads) while the save_live_complete_precopy_end handler is supposed to wait until such transfer has finished (for example, until the sending threads have exited). Signed-off-by: Maciej S. Szmigiero --- include/migration/register.h | 34 ++++++++++++++++++++++++++++++++++ migration/savevm.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+) diff --git a/include/migration/register.h b/include/migration/register.h index f60e797894e5..f7b3df799991 100644 --- a/include/migration/register.h +++ b/include/migration/register.h @@ -103,6 +103,40 @@ typedef struct SaveVMHandlers { */ int (*save_live_complete_precopy)(QEMUFile *f, void *opaque); + /** + * @save_live_complete_precopy_begin + * + * Called at the end of a precopy phase, before all @save_live_complete_precopy + * handlers. The handler might, for example, arrange for device-specific + * asynchronous transmission of the remaining data. When postcopy is enabled, + * devices that support postcopy will skip this step. + * + * @f: QEMUFile where the handler can synchronously send data before returning + * @idstr: this device section idstr + * @instance_id: this device section instance_id + * @opaque: data pointer passed to register_savevm_live() + * + * Returns zero to indicate success and negative for error + */ + int (*save_live_complete_precopy_begin)(QEMUFile *f, + char *idstr, uint32_t instance_id, + void *opaque); + /** + * @save_live_complete_precopy_end + * + * Called at the end of a precopy phase, after all @save_live_complete_precopy + * handlers. The handler might, for example, wait for the asynchronous + * transmission started by the @save_live_complete_precopy_begin handler + * to complete. When postcopy is enabled, devices that support postcopy will + * skip this step. + * + * @f: QEMUFile where the handler can synchronously send data before returning + * @opaque: data pointer passed to register_savevm_live() + * + * Returns zero to indicate success and negative for error + */ + int (*save_live_complete_precopy_end)(QEMUFile *f, void *opaque); + /* This runs both outside and inside the BQL. */ /** diff --git a/migration/savevm.c b/migration/savevm.c index c621f2359ba3..56fb1c4c2563 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -1494,6 +1494,27 @@ int qemu_savevm_state_complete_precopy_iterable(QEMUFile *f, bool in_postcopy) SaveStateEntry *se; int ret; + QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { + if (!se->ops || (in_postcopy && se->ops->has_postcopy && + se->ops->has_postcopy(se->opaque)) || + !se->ops->save_live_complete_precopy_begin) { + continue; + } + + save_section_header(f, se, QEMU_VM_SECTION_END); + + ret = se->ops->save_live_complete_precopy_begin(f, + se->idstr, se->instance_id, + se->opaque); + + save_section_footer(f, se); + + if (ret < 0) { + qemu_file_set_error(f, ret); + return -1; + } + } + QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { if (!se->ops || (in_postcopy && se->ops->has_postcopy && @@ -1525,6 +1546,20 @@ int qemu_savevm_state_complete_precopy_iterable(QEMUFile *f, bool in_postcopy) end_ts_each - start_ts_each); } + QTAILQ_FOREACH(se, &savevm_state.handlers, entry) { + if (!se->ops || (in_postcopy && se->ops->has_postcopy && + se->ops->has_postcopy(se->opaque)) || + !se->ops->save_live_complete_precopy_end) { + continue; + } + + ret = se->ops->save_live_complete_precopy_end(f, se->opaque); + if (ret < 0) { + qemu_file_set_error(f, ret); + return -1; + } + } + trace_vmstate_downtime_checkpoint("src-iterable-saved"); return 0;