From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753697AbaJMHr0 (ORCPT ); Mon, 13 Oct 2014 03:47:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:27619 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753652AbaJMHrT (ORCPT ); Mon, 13 Oct 2014 03:47:19 -0400 Date: Mon, 13 Oct 2014 10:50:33 +0300 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: Rusty Russell , virtualization@lists.linux-foundation.org, linux-scsi@vger.kernel.org, linux-s390@vger.kernel.org, v9fs-developer@lists.sourceforge.net, netdev@vger.kernel.org, kvm@vger.kernel.org, Amit Shah , Cornelia Huck , Christian Borntraeger , "David S. Miller" , Paolo Bonzini Subject: [PATCH v4 10/25] virtio: add API to enable VQs early Message-ID: <1413114332-626-11-git-send-email-mst-v4@redhat.com> References: <1413114332-626-1-git-send-email-mst-v4@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1413114332-626-1-git-send-email-mst-v4@redhat.com> X-Mutt-Fcc: =sent Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org virtio spec 0.9.X 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 under virtio 1.0 transitional devices support this behaviour, we want to make it possible for those early callers to become spec compliant and eventually support non-transitional devices. Add API for drivers to call before using VQs. Sets DRIVER_OK internally. Signed-off-by: Michael S. Tsirkin Reviewed-by: Cornelia Huck --- 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..e36403b 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_device_ready - 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_device_ready(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); +} + static inline const char *virtio_bus_name(struct virtio_device *vdev) { -- MST