From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36533) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a5zJH-0006JY-IJ for qemu-devel@nongnu.org; Mon, 07 Dec 2015 12:10:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a5zJG-00088J-Es for qemu-devel@nongnu.org; Mon, 07 Dec 2015 12:10:47 -0500 Received: from mail-vk0-x234.google.com ([2607:f8b0:400c:c05::234]:33601) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a5zJG-00088D-7X for qemu-devel@nongnu.org; Mon, 07 Dec 2015 12:10:46 -0500 Received: by vkca188 with SMTP id a188so107272035vkc.0 for ; Mon, 07 Dec 2015 09:10:45 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <5665A36B.1060502@redhat.com> References: <1449485967-19240-1-git-send-email-famz@redhat.com> <20151207122949.72abc5ce.cornelia.huck@de.ibm.com> <20151207130240.GH32154@ad.usersys.redhat.com> <5665A36B.1060502@redhat.com> From: Peter Maydell Date: Mon, 7 Dec 2015 17:10:26 +0000 Message-ID: Content-Type: text/plain; charset=UTF-8 Subject: Re: [Qemu-devel] [PATCH] virtio-blk: Drop x-data-plane option List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Kevin Wolf , Fam Zheng , Qemu-block , QEMU Developers , Stefan Hajnoczi , Cornelia Huck On 7 December 2015 at 15:19, Paolo Bonzini wrote: > > > On 07/12/2015 14:02, Fam Zheng wrote: >> On Mon, 12/07 12:29, Cornelia Huck wrote: >>> On Mon, 7 Dec 2015 18:59:27 +0800 >>> Fam Zheng wrote: >>> >>>> The official way of enabling dataplane is through the "iothread" >>>> property that references an iothread object created by "-object >>>> iothread". Since the old "x-data-plane=on" way now even crashes, it's >>>> probably easier to just drop it: >>>> >>>> $ qemu-system-x86_64 -drive file=null-co://,id=d0,if=none \ >>>> -device virtio-blk-pci,drive=d0,x-data-plane=on >>>> >>>> ERROR:/home/fam/work/qemu/qom/object.c:1515: >>>> object_get_canonical_path_component: assertion failed: (obj->parent != NULL) >>>> Aborted >>> >>> Do we understand yet why this crashes, btw? >> >> I think it's because with x-data-plane=on, virtio-blk initialize an object that >> doesn't have a parent, therefore it doesn't have a valid "canonical path >> component" thing, which is different from objects created with "-object" CLI. >> I'm not very familiar with the QOM semantics here. >> >>> >>>> >>>> Signed-off-by: Fam Zheng >>>> --- >>>> hw/block/dataplane/virtio-blk.c | 15 ++------------- >>>> hw/block/virtio-blk.c | 1 - >>>> include/hw/virtio/virtio-blk.h | 1 - >>>> 3 files changed, 2 insertions(+), 15 deletions(-) >>>> >>> >>> No general objection to removing x-data-plane; but this probably wants >>> a mention on the changelog as x-data-plane has been described in >>> various howtos etc. over the years. >> >> Yes, that is a good point. I don't know if it's too rushing in removing it for >> 2.5 (this is just posted as one option) and we'll have to count on QOM experts >> for the fix, if it is. > > The solution would be to add object_property_add_child to > virtio_blk_data_plane_create, between object_initialize and > user_creatable_complete. But I think this patch is ok for 2.5. Paolo asked me to apply this to master, so I have done so. thanks -- PMM