From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39071) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cdKm0-0003Xs-DD for qemu-devel@nongnu.org; Mon, 13 Feb 2017 12:50:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cdKly-0005wG-Tr for qemu-devel@nongnu.org; Mon, 13 Feb 2017 12:50:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36636) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cdKly-0005vv-Mh for qemu-devel@nongnu.org; Mon, 13 Feb 2017 12:50:46 -0500 From: "Dr. David Alan Gilbert (git)" Date: Mon, 13 Feb 2017 17:50:25 +0000 Message-Id: <20170213175033.7314-7-dgilbert@redhat.com> In-Reply-To: <20170213175033.7314-1-dgilbert@redhat.com> References: <20170213175033.7314-1-dgilbert@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PULL 06/14] migrate: Introduce zero RAM checks to skip RAM migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: quintela@redhat.com, ashijeetacharya@gmail.com, amit@kernel.org, pbutsykin@virtuozzo.com, zhang.zhanghailiang@huawei.com From: Ashijeet Acharya 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 Message-Id: <1486564125-31366-1-git-send-email-ashijeetacharya@gmail.com> Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Philippe Mathieu-Daud=C3=A9 Signed-off-by: Dr. David Alan Gilbert --- migration/ram.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index 67f2efb..f289fcd 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1346,6 +1346,11 @@ static int ram_find_and_save_block(QEMUFile *f, bo= ol 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; @@ -1952,14 +1957,17 @@ 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_pa= ges); + bitmap_set(migration_bitmap_rcu->unsentmap, 0, ram_bitmap_pa= ges); + } } =20 /* --=20 2.9.3