I submit one split patch for review to make sure that's the right format. I copied Rusty's comment for the commit message, and change destroy to detach since we destroy the buffers in caller. This patch is built against Dave's net-next tree.
There's currently no way for a virtio driver to ask for unused buffers, so it has to keep a list itself to reclaim them at shutdown. This is redundant, since virtio_ring stores that information. So add a new hook to do this: virtio_net will be the first user. Signed-off-by: Shirley Ma <[email protected]> --- drivers/virtio/virtio_ring.c | 24 ++++++++++++++++++++++++ include/linux/virtio.h | 1 + 2 files changed, 25 insertions(+), 0 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index fbd2ecd..f847bc3 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -334,6 +334,29 @@ static bool vring_enable_cb(struct virtqueue *_vq) return true; } +/* This function is used to return vring unused buffers to caller for free */ +static void *vring_detach_bufs(struct virtqueue *_vq) +{ + struct vring_virtqueue *vq = to_vvq(_vq); + unsigned int i; + + START_USE(vq); + + for (i = 0; i < vq->vring.num; ++i) { + if (vq->data[i]) { + /* detach_buf clears data, so grab it now. */ + detach_buf(vq, i); + END_USE(vq); + return vq->data[i]; + } + } + /* That should have freed everything. */ + BUG_ON(vq->num_free != vq->vring.num); + + END_USE(vq); + return NULL; +} + irqreturn_t vring_interrupt(int irq, void *_vq) { struct vring_virtqueue *vq = to_vvq(_vq); @@ -360,6 +383,7 @@ static struct virtqueue_ops vring_vq_ops = { .kick = vring_kick, .disable_cb = vring_disable_cb, .enable_cb = vring_enable_cb, + .detach_bufs = vring_detach_bufs, }; struct virtqueue *vring_new_virtqueue(unsigned int num, diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 057a2e0..d7da456 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -71,6 +71,7 @@ struct virtqueue_ops { void (*disable_cb)(struct virtqueue *vq); bool (*enable_cb)(struct virtqueue *vq); + void *(*detach_bufs)(struct virtqueue *vq); }; /** Thanks Shirley -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
