From nobody Wed May 1 20:04:54 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1486564211196247.73032985516159; Wed, 8 Feb 2017 06:30:11 -0800 (PST) Received: from localhost ([::1]:59844 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cbTG5-00077B-Vy for importer@patchew.org; Wed, 08 Feb 2017 09:30:10 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53360) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cbTEo-0006Wd-2n for qemu-devel@nongnu.org; Wed, 08 Feb 2017 09:28:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cbTEk-00066Z-3Q for qemu-devel@nongnu.org; Wed, 08 Feb 2017 09:28:50 -0500 Received: from mail-pg0-x244.google.com ([2607:f8b0:400e:c05::244]:36759) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cbTEj-00066M-S6 for qemu-devel@nongnu.org; Wed, 08 Feb 2017 09:28:46 -0500 Received: by mail-pg0-x244.google.com with SMTP id 75so15335124pgf.3 for ; Wed, 08 Feb 2017 06:28:45 -0800 (PST) Received: from linux.local ([27.251.197.196]) by smtp.gmail.com with ESMTPSA id p14sm20917418pfl.75.2017.02.08.06.28.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 08 Feb 2017 06:28:44 -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=OaUrfoeot32fjpdQUCgoubM9kKy2ruPgom5CX4ufR1I=; b=MVNjlfxULKBDRGHTKMcqoXqW3zyhWIcz6c8tlFWxZHPj4Ne9+pmLeNFuBZo0cpEiS1 gT1RndVSPh4VtuU4GM7IU3TLNkDGXi9GUriJv16B865Jh8Db59CmfHrJu2K0I5nOXyNA iaVtIyR/tDvAghcV9rg+0Sn8UYNmTuHrEBjvM4f9NCY3ORuWqNLnYfSNzR9lQ4PRsFDO VPyStxhjwUWHwNZqIzaJWM/0Ctyxf25A2//6WY3H988eG63O+fKg70ndvDIc4j7V2qMc 4Hng0b/OCEApBrR9HnIFuCTHWDQr2kda9n7JqYlWRA4EgpK0FdqcbcTNx1KtF5vRMK5H jNwA== 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=OaUrfoeot32fjpdQUCgoubM9kKy2ruPgom5CX4ufR1I=; b=M6YKvqLUWP+Td3qu5k1XB6XE7t7u3vs0SFpKIIUqQ4jWm/Oeo8o1VCcQYn7zf0D7ZO BNDMhEBFJ8lbBmr+lOCvaeU7cQVrmI4Z9nAhDHwYjm0ZWJFo/aLUNuw3xjwbOaO9eIt+ 7qmh1E7LoXlrRszVlAI2eTi1f2v+haDemFl/dX0wreOtWwqNm+7mesqiVutPo2hMsXPb 57T59znUfcfsBvfZyK4BbQK0n0n85QYjy9p/RYVAJQUGDNtf8IvQl7JCZ+vlW6A5iJQx awTh9ar1A4f8NZ31aXaO2s/xEVaqRuWzYsaQuQUThhbh9f2hxPI+oBg+2UddaTUTEX27 N8pQ== X-Gm-Message-State: AIkVDXJckD51lIiauJN7TaxlHgWnNCNN+sXBsFzhXafWz6pwbCIVprT6RP/BpCWxhlG0hA== X-Received: by 10.84.197.1 with SMTP id m1mr34574755pld.123.1486564124826; Wed, 08 Feb 2017 06:28:44 -0800 (PST) From: Ashijeet Acharya To: thuth@redhat.com Date: Wed, 8 Feb 2017 19:58:45 +0530 Message-Id: <1486564125-31366-1-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::244 Subject: [Qemu-devel] [PATCH v3] 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, Ashijeet Acharya , pbonzini@redhat.com, dgilbert@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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 Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Philippe Mathieu-Daud=C3=A9 --- Changes in v3: - handle migration cleanup appropriately (Dave) 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..faff5ab 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 */ =20 + /* No dirty page as there is zero RAM */ + if (!ram_bytes_total()) { + return pages; + } + pss.block =3D last_seen_block; pss.offset =3D last_offset; pss.complete_round =3D false; @@ -1912,14 +1917,17 @@ static int ram_save_init_globals(void) bytes_transferred =3D 0; reset_ram_globals(); =20 - ram_bitmap_pages =3D last_ram_offset() >> TARGET_PAGE_BITS; migration_bitmap_rcu =3D g_new0(struct BitmapRcu, 1); - migration_bitmap_rcu->bmap =3D bitmap_new(ram_bitmap_pages); - bitmap_set(migration_bitmap_rcu->bmap, 0, ram_bitmap_pages); - - if (migrate_postcopy_ram()) { - migration_bitmap_rcu->unsentmap =3D bitmap_new(ram_bitmap_pages); - bitmap_set(migration_bitmap_rcu->unsentmap, 0, ram_bitmap_pages); + /* Skip setting bitmap if there is no RAM */ + if (ram_bytes_total()) { + ram_bitmap_pages =3D last_ram_offset() >> TARGET_PAGE_BITS; + migration_bitmap_rcu->bmap =3D bitmap_new(ram_bitmap_pages); + bitmap_set(migration_bitmap_rcu->bmap, 0, ram_bitmap_pages); + + if (migrate_postcopy_ram()) { + migration_bitmap_rcu->unsentmap =3D bitmap_new(ram_bitmap_page= s); + bitmap_set(migration_bitmap_rcu->unsentmap, 0, ram_bitmap_page= s); + } } =20 /* --=20 2.6.2