Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932306AbaKMJPM (ORCPT ); Thu, 13 Nov 2014 04:15:12 -0500 Received: from e06smtp10.uk.ibm.com ([195.75.94.106]:48238 "EHLO e06smtp10.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932098AbaKMJPC (ORCPT ); Thu, 13 Nov 2014 04:15:02 -0500 Date: Thu, 13 Nov 2014 10:14:56 +0100 From: Cornelia Huck To: Jason Wang Cc: rusty@rustcorp.com.au, mst@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH 1/2] virito: introduce methods of fixing device features Message-ID: <20141113101456.43acfdb7.cornelia.huck@de.ibm.com> In-Reply-To: <546475C2.50606@redhat.com> References: <1415857974-23326-1-git-send-email-jasowang@redhat.com> <20141113094604.1f248c3d.cornelia.huck@de.ibm.com> <546475C2.50606@redhat.com> Organization: IBM Deutschland Research & Development GmbH Vorsitzende des Aufsichtsrats: Martina Koederitz =?UTF-8?B?R2VzY2jDpGZ0c2bDvGhydW5nOg==?= Dirk Wittkopp Sitz der Gesellschaft: =?UTF-8?B?QsO2Ymxpbmdlbg==?= Registergericht: Amtsgericht Stuttgart, HRB 243294 X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14111309-0041-0000-0000-0000021AC6F7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 13 Nov 2014 17:11:30 +0800 Jason Wang wrote: > On 11/13/2014 04:46 PM, Cornelia Huck wrote: > > On Thu, 13 Nov 2014 13:52:53 +0800 > > Jason Wang wrote: > >> +static inline void virtio_disable_feature(struct virtio_device *vdev, > >> + unsigned int fbit) > >> +{ > >> + BUG_ON(fbit >= VIRTIO_TRANSPORT_F_START); > >> + BUG_ON(vdev->config->get_status(vdev) & > >> + ~(VIRTIO_CONFIG_S_ACKNOWLEDGE | VIRTIO_CONFIG_S_DRIVER)); > > When we add virtio-1 support, we can add a check for FEATURES_OK here, > > so we're really on the safe side. > > > > If I read the spec correctly, FEATURES_OK was set only after writing the > features bits to device. But we want to sanitize the them before. I meant doing a BUG when FEATURES_OK is set - sorry for not being clear. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/