Commit 18445c4d authored by Rusty Russell's avatar Rusty Russell
Browse files

virtio: explicit enable_cb/disable_cb rather than callback return.

It seems that virtio_net wants to disable callbacks (interrupts) before
calling netif_rx_schedule(), so we can't use the return value to do so.

Rename "restart" to "cb_enable" and introduce "cb_disable" hook: callback
now returns void, rather than a boolean.
Signed-off-by: default avatarRusty Russell <>
parent a586d4f6
......@@ -36,7 +36,7 @@ struct virtblk_req
struct virtio_blk_inhdr in_hdr;
static bool blk_done(struct virtqueue *vq)
static void blk_done(struct virtqueue *vq)
struct virtio_blk *vblk = vq->vdev->priv;
struct virtblk_req *vbr;
......@@ -65,7 +65,6 @@ static bool blk_done(struct virtqueue *vq)
/* In case queue is stopped waiting for more buffers. */
spin_unlock_irqrestore(&vblk->lock, flags);
return true;
static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
......@@ -191,7 +191,7 @@ static void lg_notify(struct virtqueue *vq)
* So we provide devices with a "find virtqueue and set it up" function. */
static struct virtqueue *lg_find_vq(struct virtio_device *vdev,
unsigned index,
bool (*callback)(struct virtqueue *vq))
void (*callback)(struct virtqueue *vq))
struct lguest_device *ldev = to_lgdev(vdev);
struct lguest_vq_info *lvq;
......@@ -52,13 +52,12 @@ static inline void vnet_hdr_to_sg(struct scatterlist *sg, struct sk_buff *skb)
sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
static bool skb_xmit_done(struct virtqueue *rvq)
static void skb_xmit_done(struct virtqueue *rvq)
struct virtnet_info *vi = rvq->vdev->priv;
/* In case we were waiting for output buffers. */
return true;
static void receive_skb(struct net_device *dev, struct sk_buff *skb,
......@@ -161,12 +160,14 @@ static void try_fill_recv(struct virtnet_info *vi)
static bool skb_recv_done(struct virtqueue *rvq)
static void skb_recv_done(struct virtqueue *rvq)
struct virtnet_info *vi = rvq->vdev->priv;
netif_rx_schedule(vi->dev, &vi->napi);
/* Suppress further interrupts. */
return false;
/* Schedule NAPI, Suppress further interrupts if successful. */
if (netif_rx_schedule_prep(vi->dev, &vi->napi)) {
__netif_rx_schedule(vi->dev, &vi->napi);
static int virtnet_poll(struct napi_struct *napi, int budget)
......@@ -192,7 +193,7 @@ again:
/* Out of packets? */
if (received < budget) {
netif_rx_complete(vi->dev, napi);
if (unlikely(!vi->rvq->vq_ops->restart(vi->rvq))
if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
&& netif_rx_reschedule(vi->dev, napi))
goto again;
......@@ -220,7 +220,17 @@ static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len)
return ret;
static bool vring_restart(struct virtqueue *_vq)
static void vring_disable_cb(struct virtqueue *_vq)
struct vring_virtqueue *vq = to_vvq(_vq);
BUG_ON(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT);
vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
static bool vring_enable_cb(struct virtqueue *_vq)
struct vring_virtqueue *vq = to_vvq(_vq);
......@@ -254,8 +264,8 @@ irqreturn_t vring_interrupt(int irq, void *_vq)
pr_debug("virtqueue callback for %p (%p)\n", vq, vq->vq.callback);
if (vq->vq.callback && !vq->vq.callback(&vq->vq))
vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
if (vq->vq.callback)
......@@ -264,7 +274,8 @@ static struct virtqueue_ops vring_vq_ops = {
.add_buf = vring_add_buf,
.get_buf = vring_get_buf,
.kick = vring_kick,
.restart = vring_restart,
.disable_cb = vring_disable_cb,
.enable_cb = vring_enable_cb,
.shutdown = vring_shutdown,
......@@ -272,7 +283,7 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
struct virtio_device *vdev,
void *pages,
void (*notify)(struct virtqueue *),
bool (*callback)(struct virtqueue *))
void (*callback)(struct virtqueue *))
struct vring_virtqueue *vq;
unsigned int i;
......@@ -11,15 +11,13 @@
* virtqueue - a queue to register buffers for sending or receiving.
* @callback: the function to call when buffers are consumed (can be NULL).
* If this returns false, callbacks are suppressed until vq_ops->restart
* is called.
* @vdev: the virtio device this queue was created for.
* @vq_ops: the operations for this virtqueue (see below).
* @priv: a pointer for the virtqueue implementation to use.
struct virtqueue
bool (*callback)(struct virtqueue *vq);
void (*callback)(struct virtqueue *vq);
struct virtio_device *vdev;
struct virtqueue_ops *vq_ops;
void *priv;
......@@ -41,7 +39,9 @@ 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.
* @restart: restart callbacks after callback returned false.
* @disable_cb: disable callbacks
* vq: the struct virtqueue we're talking about.
* @enable_cb: restart callbacks after disable_cb.
* vq: the struct virtqueue we're talking about.
* This returns "false" (and doesn't re-enable) if there are pending
* buffers in the queue, to avoid a race.
......@@ -65,7 +65,8 @@ struct virtqueue_ops {
void *(*get_buf)(struct virtqueue *vq, unsigned int *len);
bool (*restart)(struct virtqueue *vq);
void (*disable_cb)(struct virtqueue *vq);
bool (*enable_cb)(struct virtqueue *vq);
void (*shutdown)(struct virtqueue *vq);
......@@ -61,7 +61,7 @@ struct virtio_config_ops
void (*set_status)(struct virtio_device *vdev, u8 status);
struct virtqueue *(*find_vq)(struct virtio_device *vdev,
unsigned index,
bool (*callback)(struct virtqueue *));
void (*callback)(struct virtqueue *));
void (*del_vq)(struct virtqueue *vq);
......@@ -114,7 +114,7 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
struct virtio_device *vdev,
void *pages,
void (*notify)(struct virtqueue *vq),
bool (*callback)(struct virtqueue *vq));
void (*callback)(struct virtqueue *vq));
void vring_del_virtqueue(struct virtqueue *vq);
irqreturn_t vring_interrupt(int irq, void *_vq);
......@@ -199,14 +199,12 @@ static void p9_virtio_close(struct p9_trans *trans)
static bool p9_virtio_intr(struct virtqueue *q)
static void p9_virtio_intr(struct virtqueue *q)
struct virtio_chan *chan = q->vdev->priv;
P9_DPRINTK(P9_DEBUG_TRANS, "9p poll_wakeup: %p\n", &chan->wq);
return true;
static int p9_virtio_probe(struct virtio_device *dev)
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