From patchwork Fri Feb 3 10:36:38 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ashijeet Acharya X-Patchwork-Id: 723554 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 3vFCxZ0B9Xz9s79 for ; Fri, 3 Feb 2017 21:37:53 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="EsWFlZQa"; dkim-atps=neutral Received: from localhost ([::1]:33230 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cZbFW-0002TM-Rt for incoming@patchwork.ozlabs.org; Fri, 03 Feb 2017 05:37:50 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56189) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cZbEO-0001Nj-QU for qemu-devel@nongnu.org; Fri, 03 Feb 2017 05:36:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cZbEM-0002mv-7s for qemu-devel@nongnu.org; Fri, 03 Feb 2017 05:36:40 -0500 Received: from mail-pg0-x241.google.com ([2607:f8b0:400e:c05::241]:35198) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cZbEM-0002lr-0P for qemu-devel@nongnu.org; Fri, 03 Feb 2017 05:36:38 -0500 Received: by mail-pg0-x241.google.com with SMTP id 204so1688662pge.2 for ; Fri, 03 Feb 2017 02:36:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=bnqha3eV+4RJr4DClB9HccbdVcxZWQvGDPw3OtYbgCA=; b=EsWFlZQa91ie5k1lEOXcIN8tyrz+mgiju01La0kTp8+vURmgZfHdL7PaATCK52Ubsn rjeivbWf0rn2ia17wPqXrMFIqecGH6FO1KPlIgBYUo4fIgcCUxjmKrVuPoFkuMwV7wm4 yNeyp8hwIkq5Ve3DWwIUluC1+C+Mq7EOznGoMnMNCSRF1OkbZ8ytuOk6Sj5VEPvQ00vy ldKCSDRZnY/zeSkaOpkM+XlIcO0nF+1ozz+nzkLnObqdzUvKMtHcyJ4oTLFgnfqCZvMI ZckPPkxvdfTNcM8bg29kCIe7zV7vri4+ZR896lc9cI2sxYAVoAJ2mJ9Ak7JyCmnQB90U zCnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=bnqha3eV+4RJr4DClB9HccbdVcxZWQvGDPw3OtYbgCA=; b=hoRT4khSezBUHf1JisejTwOIUFteAe9G754hw5lI1U73GTUXbNJEWs+SYsalR7lDzV px6jAfbRJxVYrYxrY7JwJWz6YwoSsM1a5vnewt/nCp+zxTjyK/Dxj97P2uZX16kW4xYr 7I/2X9tT53kFrbynWJlRqe9QnVCivx9MgrDkPiOh7t2HDVvR0XjwqQ9ND/obJhPRBl7j Q3ziHR4v2dwZgCZg1gfCQRdIAipcyDSTO79Zsz8X5mM68MOiHBYl1q2PB92figXvr2Z1 FFX4SmlOcjUT94DV6crinf8Vl98Rhw94gG+3haGfc910Pv7v3lLPkoP9ic83By9Km9MG 1QUw== X-Gm-Message-State: AIkVDXKfvMDgFedA5bkk8Yt2M5MSHfOgX4PKlCifsnxOoQJC2O3u1KHsevSRWzZKtlifOw== X-Received: by 10.84.233.132 with SMTP id l4mr20216007plk.15.1486118196726; Fri, 03 Feb 2017 02:36:36 -0800 (PST) Received: from linux.local ([27.251.197.196]) by smtp.gmail.com with ESMTPSA id u75sm66464325pgc.31.2017.02.03.02.36.33 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 03 Feb 2017 02:36:36 -0800 (PST) From: Ashijeet Acharya To: thuth@redhat.com Date: Fri, 3 Feb 2017 16:06:38 +0530 Message-Id: <1486118198-8965-1-git-send-email-ashijeetacharya@gmail.com> X-Mailer: git-send-email 2.6.2 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2607:f8b0:400e:c05::241 Subject: [Qemu-devel] [PATCH v2] migrate: Introduce zero RAM checks to skip RAM migration X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: quintela@redhat.com, qemu-devel@nongnu.org, groug@kaod.org, dgilbert@redhat.com, Ashijeet Acharya , amit.shah@redhat.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Migration of a "none" machine with no RAM crashes abruptly as bitmap_new() fails and thus aborts. Instead place zero RAM checks at appropriate places to skip migration of RAM in this case and complete migration successfully for devices only. Signed-off-by: Ashijeet Acharya --- Changes in v2: - try to migrate successfully by skipping RAM (Paolo, Greg) - drop the idea of erroring out and failing nicely migration/ram.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index ef8fadf..2f19566 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1325,6 +1325,11 @@ static int ram_find_and_save_block(QEMUFile *f, bool last_stage, ram_addr_t dirty_ram_abs; /* Address of the start of the dirty page in ram_addr_t space */ + /* No dirty page as there is zero RAM */ + if (!ram_bytes_total()) { + return pages; + } + pss.block = last_seen_block; pss.offset = last_offset; pss.complete_round = false; @@ -1912,14 +1917,17 @@ static int ram_save_init_globals(void) bytes_transferred = 0; reset_ram_globals(); - ram_bitmap_pages = last_ram_offset() >> TARGET_PAGE_BITS; - migration_bitmap_rcu = g_new0(struct BitmapRcu, 1); - migration_bitmap_rcu->bmap = bitmap_new(ram_bitmap_pages); - bitmap_set(migration_bitmap_rcu->bmap, 0, ram_bitmap_pages); + /* Skip setting bitmap if there is no RAM */ + if (ram_bytes_total()) { + ram_bitmap_pages = last_ram_offset() >> TARGET_PAGE_BITS; + migration_bitmap_rcu = g_new0(struct BitmapRcu, 1); + migration_bitmap_rcu->bmap = bitmap_new(ram_bitmap_pages); + bitmap_set(migration_bitmap_rcu->bmap, 0, ram_bitmap_pages); - if (migrate_postcopy_ram()) { - migration_bitmap_rcu->unsentmap = bitmap_new(ram_bitmap_pages); - bitmap_set(migration_bitmap_rcu->unsentmap, 0, ram_bitmap_pages); + if (migrate_postcopy_ram()) { + migration_bitmap_rcu->unsentmap = bitmap_new(ram_bitmap_pages); + bitmap_set(migration_bitmap_rcu->unsentmap, 0, ram_bitmap_pages); + } } /*