From mboxrd@z Thu Jan 1 00:00:00 1970 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 lists1p.gnu.org (lists1p.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 4B2C4C43458 for ; Tue, 7 Jul 2026 06:30:01 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wgzJZ-0001AC-UC; Tue, 07 Jul 2026 02:29:54 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wgzJT-00019v-8X for qemu-devel@nongnu.org; Tue, 07 Jul 2026 02:29:47 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wgzJR-0006en-Q4 for qemu-devel@nongnu.org; Tue, 07 Jul 2026 02:29:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1783405785; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=K2GeVWVj42TRRgoCrVjZPsNMY1WIblmTifASA+IvYbY=; b=bireWkLw+y0vCmB3RV0S0mpuzDkiSqRcMoZHmiFhoPl4z9rkBhDVbm5Y2QAO7F2Wbj/Ar6 ySeKWPzKlXRDC3luFsUJhSWw99CgxqhjAr+TldNd+ZXUu0m3ZPlHs0uyqaA6TTALn7WXqs Cd05zSB7yY/KE/MYU+4psU/DPnl44X8= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-206-fYVcaIusMRyV-oE-yF5OMg-1; Tue, 07 Jul 2026 02:29:41 -0400 X-MC-Unique: fYVcaIusMRyV-oE-yF5OMg-1 X-Mimecast-MFC-AGG-ID: fYVcaIusMRyV-oE-yF5OMg_1783405781 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0C14F1955D48; Tue, 7 Jul 2026 06:29:41 +0000 (UTC) Received: from corto.redhat.com (unknown [10.44.32.49]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 93A821800678; Tue, 7 Jul 2026 06:29:39 +0000 (UTC) From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= To: qemu-devel@nongnu.org Cc: Avihai Horon , Peter Xu , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Subject: [PULL 07/27] migration/ram: Use migration_bitmap_sync_precopy() for postcopy discard Date: Tue, 7 Jul 2026 08:29:00 +0200 Message-ID: <20260707062920.317302-8-clg@redhat.com> In-Reply-To: <20260707062920.317302-1-clg@redhat.com> References: <20260707062920.317302-1-clg@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.133.124; envelope-from=clg@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 8 X-Spam_score: 0.8 X-Spam_bar: / X-Spam_report: (0.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.445, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development 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: Avihai Horon ram_postcopy_send_discard_bitmap() performs the final RAM dirty bitmap sync at postcopy switchover, before sending discard bitmap to the destination. Unlike the precopy switchover path, it currently calls the raw migration_bitmap_sync() helper and passes last_stage=false. Postcopy switchover is also a stopped-VM final sync point, so use migration_bitmap_sync_precopy(true). This keeps RAM final bitmap sync handling consistent across precopy and postcopy switchover, including the precopy bitmap-sync notifier wrapper. Current notifier users are safe in postcopy: virtio-balloon free-page hinting already opts out when postcopy-ram is enabled [1]. This prepares for moving the final sync out of RAM completion/discard paths and into migration_switchover_start(), where the migration core can run a final save_query_pending pass for all modules uniformly. [1] fd51e54fa102 ("virtio-balloon: don't start free page hinting if postcopy is possible") Reviewed-by: Peter Xu Signed-off-by: Avihai Horon Link: https://lore.kernel.org/qemu-devel/20260706085211.13905-3-avihaih@nvidia.com Signed-off-by: Cédric Le Goater --- migration/ram.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/migration/ram.c b/migration/ram.c index bd519f1931cb0d0cde27765a95730179aba03027..55aa9b47dc8ab8463fd1aeba19726a493b81b070 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -2687,7 +2687,7 @@ void ram_postcopy_send_discard_bitmap(MigrationState *ms) RCU_READ_LOCK_GUARD(); /* This should be our last sync, the src is now paused */ - migration_bitmap_sync(rs, false); + migration_bitmap_sync_precopy(true); /* Easiest way to make sure we don't resume in the middle of a host-page */ rs->pss[RAM_CHANNEL_PRECOPY].last_sent_block = NULL; -- 2.54.0