From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752843AbaJFOsV (ORCPT ); Mon, 6 Oct 2014 10:48:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36412 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751344AbaJFOsU (ORCPT ); Mon, 6 Oct 2014 10:48:20 -0400 Date: Mon, 6 Oct 2014 17:51:47 +0300 From: "Michael S. Tsirkin" To: Cornelia Huck 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: <20141006145147.GB29955@redhat.com> References: <1412525038-15871-1-git-send-email-mst@redhat.com> <1412525038-15871-11-git-send-email-mst@redhat.com> <20141006160816.68490a49.cornelia.huck@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141006160816.68490a49.cornelia.huck@de.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 06, 2014 at 04:08:16PM +0200, Cornelia Huck wrote: > 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." > > ? Exactly. > > > > 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? OK. > > static inline > > const char *virtio_bus_name(struct virtio_device *vdev) > > {