On Fri, Feb 22, 2013 at 1:42 AM, Rusty Russell <[email protected]> wrote:
> Ohad Ben-Cohen <[email protected]> writes:
>> On Thu, Feb 21, 2013 at 8:37 AM, Rusty Russell <[email protected]> wrote:
>> What do you think about creating some virtio-level wrappers for the
>> vringh handlers?
>>
>> I don't think we're going to stop with caif as the only vringh user,
>> and it could be nice if we follow the virtio spirit of decoupling the
>> drivers from the low level implementation. It sure did prove itself
>> when the remoteproc use cases started showing up, and it's neat.
>
> The problem space is a bit different. My immediate concern is getting
> vhost (and thus vhost_net/blk) to use vringh: I wanted to unify the
> in-userspace and in-kernelspace ring implementations. We don't have
> that issue in virtqueue.c.
>
> vhost is (will be) the higher abstraction for in-userspace rings,
> perhaps we want an equivalent for in-kernelspace rings. I'm happy to
> look at patches, but I don't immediately see what it would look like...
I'm not sure if the tight binding between vringh and remoteproc is
a big problem. I think the most obvious use-case for kernel vringh is
when they are instantiated from remoteproc.
But if we where to make wrappers, how about something like this?
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 29b9104..ca257d8 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -53,0 +54,8 @@
+ * @find_vrh: find the host vrings and instantiate them
+ * vdev: the virtio_device
+ * nhvrs: the number of host vrings to find
+ * hvrs: on success, includes new host vrings
+ * callbacks: array of driver callbacks, for each host vring
+ * include a NULL entry for vqs that do not need a callback
+ * Returns 0 on success or error status
+ * @del_vrh: free the host vrings found by find_vrh().
@@ -55,0 +64 @@ typedef void vq_callback_t(struct virtqueue *);
+typedef void vrh_callback_t(struct virtio_device *, struct vringh *);
@@ -72,0 +82,4 @@ struct virtio_config_ops {
+ int (*find_vrh) (struct virtio_device *, unsigned nhvrs,
+ struct vringh *vrhs[],
+ vrh_callback_t *callbacks[]);
+ int (*del_vrhs)(struct virtio_device *);
diff --git a/include/linux/vringh.h b/include/linux/vringh.h
index 4c4c918..78aecc9 100644
--- a/include/linux/vringh.h
+++ b/include/linux/vringh.h
@@ -52,0 +53,3 @@ struct vringh {
+
+ /* The function to call when buffers are available */
+ void (*notify)(struct vringh *);
diff --git a/drivers/net/caif/caif_virtio.c b/drivers/net/caif/caif_virtio.c
index d4f339c..e657277 100644
--- a/drivers/net/caif/caif_virtio.c
+++ b/drivers/net/caif/caif_virtio.c
@@ -433,0 +434,2 @@ static int cfv_probe(struct virtio_device *vdev)
+ struct vringh *vrhs;
+ vrh_callback_t *vrh_cbs = cfv_recv;
@@ -446,2 +448,2 @@ static int cfv_probe(struct virtio_device *vdev)
- cfv->vr_rx = rproc_virtio_new_vringh(vdev, RX_RING_INDEX, cfv_recv);
- if (!cfv->vr_rx)
+ err = vdev->config->find_vrh(vdev, 1, &cfv->vr_rx, &vrh_cbs);
+ if (err)
@@ -504 +506 @@ static int cfv_probe(struct virtio_device *vdev)
- rproc_virtio_kick_vringh(vdev, RX_RING_INDEX);
+ cfv->vr_rx->notify(cfv->vr_rx);
@@ -522 +524 @@ static void cfv_remove(struct virtio_device *vdev)
- rproc_virtio_del_vringh(vdev, RX_RING_INDEX);
+ vdev->config->del_vrhs(cfv->vdev);
Thanks,
Sjur
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