From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51423) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xm0dN-00072z-QS for qemu-devel@nongnu.org; Wed, 05 Nov 2014 08:28:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xm0dI-0000ie-OD for qemu-devel@nongnu.org; Wed, 05 Nov 2014 08:28:25 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52477) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xm0dI-0000iV-Fl for qemu-devel@nongnu.org; Wed, 05 Nov 2014 08:28:20 -0500 Date: Wed, 5 Nov 2014 15:28:15 +0200 From: "Michael S. Tsirkin" Message-ID: <20141105132815.GA4884@redhat.com> References: <1415182311-13799-1-git-send-email-syeon.hwang@samsung.com> <20141105124609.GA4354@redhat.com> <87lhnpn5y1.fsf@blackfin.pond.sub.org> <545A23A7.7090401@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <545A23A7.7090401@redhat.com> Subject: Re: [Qemu-devel] [PATCH] pci: fixed mismatch of error-handling between pci_qdev_init() and qdev List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: qemu-devel@nongnu.org, Markus Armbruster , SeokYeon Hwang On Wed, Nov 05, 2014 at 02:18:31PM +0100, Paolo Bonzini wrote: > > > On 05/11/2014 14:16, Markus Armbruster wrote: > > "Michael S. Tsirkin" writes: > > > >> On Wed, Nov 05, 2014 at 07:11:51PM +0900, SeokYeon Hwang wrote: > >>> pci_qdev_init() checks whether return value is 0 or not to figure > >>> out pci device is initialized successfully. Otherwise, > >>> device_realize() in qdev checks that return value is negative value > >>> to figure out the device is realized successfully. > >>> When pci device returns positive number, pci_qdev_init() thinks that > >>> error is occured and makes the device unregistered. Nevertheless, > >>> qdev thinks that device is realized. > >>> Finally, crash is occured by commands like 'qtree' that traverse qdev list. > >>> > >>> So, pci_qdev_init() returns -1 when init function returns not 0. > >>> > >>> Signed-off-by: SeokYeon Hwang > >> > >> Question: is there a simple way to trigger this error? > > > > Next question: what's the contract of PCIDeviceClass method init()? > > Positive return value feels like bug to me... > > I think bypassing the question by converting to realize makes the most > sense... > > Paolo I'm fine with doing that but Markus's patches wouldn't yet have solved the problem by themselves since init is still around, right? This probably means fixing this bug can't justify merging the realize patchset after freeze. -- MST