Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752786AbaJFOI1 (ORCPT ); Mon, 6 Oct 2014 10:08:27 -0400 Received: from e06smtp11.uk.ibm.com ([195.75.94.107]:59668 "EHLO e06smtp11.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752758AbaJFOI0 (ORCPT ); Mon, 6 Oct 2014 10:08:26 -0400 Date: Mon, 6 Oct 2014 16:08:16 +0200 From: Cornelia Huck To: "Michael S. Tsirkin" Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: Re: [PATCH 10/16] virtio: add API to enable VQs early Message-ID: <20141006160816.68490a49.cornelia.huck@de.ibm.com> In-Reply-To: <1412525038-15871-11-git-send-email-mst@redhat.com> References: <1412525038-15871-1-git-send-email-mst@redhat.com> <1412525038-15871-11-git-send-email-mst@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: 14100614-5024-0000-0000-0000018D5154 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 5 Oct 2014 19:07:19 +0300 "Michael S. Tsirkin" wrote: > virtio spec requires DRIVER_OK to be set before > VQs are used, but some drivers use VQs before probe > function returns. > Since DRIVER_OK is set after probe, this violates the spec. "Even though transitional devices support this behaviour, we want to make it possible for those early callers to become spec compliant." ? > > Add API for drivers to call before using VQs. > > Sets DRIVER_OK internally. > > Signed-off-by: Michael S. Tsirkin > --- > include/linux/virtio_config.h | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h > index e8f8f71..6127fc8 100644 > --- a/include/linux/virtio_config.h > +++ b/include/linux/virtio_config.h > @@ -109,6 +109,23 @@ struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev, > return vq; > } > > +/** > + * virtio_early_enable_vqs - enable vq use in probe function > + * @vdev: the device > + * > + * Driver must call this to use vqs in the probe function. > + * > + * Note: vqs are enabled automatically after probe returns. > + */ > +static inline > +void virtio_early_enable_vqs(struct virtio_device *dev) > +{ > + unsigned status = dev->config->get_status(dev); > + > + BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK); > + dev->config->set_status(dev, status | VIRTIO_CONFIG_S_DRIVER_OK); > +} > + Maybe virtio_enable_vqs_early() instead? > static inline > const char *virtio_bus_name(struct virtio_device *vdev) > { -- 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/