From patchwork Tue Apr 21 08:52:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 284153 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9EBEC2BA19 for ; Tue, 21 Apr 2020 08:58:50 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id A5F38206E9 for ; Tue, 21 Apr 2020 08:58:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="gG+LTR4b" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A5F38206E9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:54144 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jQojx-0005hI-QO for qemu-devel@archiver.kernel.org; Tue, 21 Apr 2020 04:58:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57310) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jQofb-0007pX-B7 for qemu-devel@nongnu.org; Tue, 21 Apr 2020 04:54:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.90_1) (envelope-from ) id 1jQofa-00019k-PB for qemu-devel@nongnu.org; Tue, 21 Apr 2020 04:54:19 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:44980 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jQofa-00018q-CR for qemu-devel@nongnu.org; Tue, 21 Apr 2020 04:54:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587459257; 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=PiYdaufXH/OcHgyja+9iT9AeZgtrLODnqhTcI1EwYAg=; b=gG+LTR4bX9tgPrdAYc/8B9XrTlsowMs+h0ITKJN4oEh18b1Anks+B47KDz3QSqhUZRpsMT iZ6Q0kmRjAV22bbH18DHs/GxvSMTvJRp61Y5sLklgzElOQVsbup3z3NainkQWI9dp+/he5 0z2D8oxAqAYXED2HVHvJvP6qOhhOzJk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-65-5B3mA3g4NdOKDmIDStIK1A-1; Tue, 21 Apr 2020 04:54:16 -0400 X-MC-Unique: 5B3mA3g4NdOKDmIDStIK1A-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 33CC9107ACCC; Tue, 21 Apr 2020 08:54:15 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-245.ams2.redhat.com [10.36.113.245]) by smtp.corp.redhat.com (Postfix) with ESMTP id 71064100EBB9; Tue, 21 Apr 2020 08:54:06 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v4 07/13] migration/ram: Discard RAM when growing RAM blocks after ram_postcopy_incoming_init() Date: Tue, 21 Apr 2020 10:52:54 +0200 Message-Id: <20200421085300.7734-8-david@redhat.com> In-Reply-To: <20200421085300.7734-1-david@redhat.com> References: <20200421085300.7734-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=207.211.31.120; envelope-from=david@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/04/21 04:54:00 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eduardo Habkost , Juan Quintela , "Michael S . Tsirkin" , David Hildenbrand , "Dr . David Alan Gilbert" , Peter Xu , Paolo Bonzini , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" In case we grow our RAM after ram_postcopy_incoming_init() (e.g., when synchronizing the RAM block state with the migration source), the resized part would not get discarded. Let's perform that when being notified about a resize while postcopy has been advised, but is not listening yet. With precopy, the process is as following: 1. VM created - RAM blocks are created 2. Incomming migration started - Postcopy is advised - All pages in RAM blocks are discarded 3. Precopy starts - RAM blocks are resized to match the size on the migration source. - RAM pages from precopy stream are loaded - Uffd handler is registered, postcopy starts listening 4. Guest started, postcopy running - Pagefaults get resolved, pages get placed Reviewed-by: Peter Xu Cc: "Dr. David Alan Gilbert" Cc: Juan Quintela Cc: Peter Xu Signed-off-by: David Hildenbrand --- migration/ram.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/migration/ram.c b/migration/ram.c index d587ecbd92..2704d32def 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -3756,6 +3756,7 @@ static SaveVMHandlers savevm_ram_handlers = { static void ram_mig_ram_block_resized(RAMBlockNotifier *n, void *host, size_t old_size, size_t new_size) { + PostcopyState ps = postcopy_state_get(); ram_addr_t offset; Error *err = NULL; RAMBlock *rb = qemu_ram_block_from_host(host, false, &offset); @@ -3776,6 +3777,35 @@ static void ram_mig_ram_block_resized(RAMBlockNotifier *n, void *host, error_free(err); migration_cancel(); } + + switch (ps) { + case POSTCOPY_INCOMING_ADVISE: + /* + * Update what ram_postcopy_incoming_init()->init_range() does at the + * time postcopy was advised. Syncing RAM blocks with the source will + * result in RAM resizes. + */ + if (old_size < new_size) { + if (ram_discard_range(rb->idstr, old_size, new_size - old_size)) { + error_report("RAM block '%s' discard of resized RAM failed", + rb->idstr); + } + } + break; + case POSTCOPY_INCOMING_NONE: + case POSTCOPY_INCOMING_RUNNING: + case POSTCOPY_INCOMING_END: + /* + * Once our guest is running, postcopy does no longer care about + * resizes. When growing, the new memory was not available on the + * source, no handler needed. + */ + break; + default: + error_report("RAM block '%s' resized during postcopy state: %d", + rb->idstr, ps); + exit(-1); + } } static RAMBlockNotifier ram_mig_ram_notifier = {