From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shirley Ma Subject: [PATCH 1/2]virtio_ring: Add capacity check API Date: Wed, 16 Mar 2011 17:10:04 -0700 Message-ID: <1300320604.3255.31.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: David Miller , kvm@vger.kernel.org, netdev@vger.kernel.org To: "Michael S. Tsirkin" , Rusty Russell Return-path: Received: from e6.ny.us.ibm.com ([32.97.182.146]:46983 "EHLO e6.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751853Ab1CQAKN (ORCPT ); Wed, 16 Mar 2011 20:10:13 -0400 Sender: kvm-owner@vger.kernel.org List-ID: Signed-off-by: Shirley Ma --- drivers/virtio/virtio_ring.c | 8 ++++++++ include/linux/virtio.h | 5 +++++ 2 files changed, 13 insertions(+), 0 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index cc2f73e..ef6d920 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -329,6 +329,14 @@ void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len) } EXPORT_SYMBOL_GPL(virtqueue_get_buf); +int virtqueue_get_capacity(struct virtqueue *_vq) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + + return vq->num_free; +} +EXPORT_SYMBOL_GPL(virtqueue_get_capacity); + void virtqueue_disable_cb(struct virtqueue *_vq) { struct vring_virtqueue *vq = to_vvq(_vq); diff --git a/include/linux/virtio.h b/include/linux/virtio.h index aff5b4f..6c7f519 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -42,6 +42,9 @@ struct virtqueue { * vq: the struct virtqueue we're talking about. * len: the length written into the buffer * Returns NULL or the "data" token handed to add_buf. + * virtqueue_get_capacity: get the current capacity of the queue + * vq: the struct virtqueue we're talking about. + * Returns remaining capacity of the queue. * virtqueue_disable_cb: disable callbacks * vq: the struct virtqueue we're talking about. * Note that this is not necessarily synchronous, hence unreliable and only @@ -82,6 +85,8 @@ void virtqueue_kick(struct virtqueue *vq); void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); +int virtqueue_get_capacity(struct virtqueue *vq); + void virtqueue_disable_cb(struct virtqueue *vq); bool virtqueue_enable_cb(struct virtqueue *vq);