lkml.org 
[lkml]   [2012]   [Apr]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH] virtio_console: link vq to port with a private pointer in struct virtqueue
Il 18/04/2012 16:21, Michael S. Tsirkin ha scritto:
>> @@ -1872,6 +1864,8 @@ static int virtcons_restore(struct virtio_device *vdev)
>> list_for_each_entry(port, &portdev->ports, list) {
>> port->in_vq = portdev->in_vqs[port->id];
>> port->out_vq = portdev->out_vqs[port->id];
>> + port->in_vq->vdev_priv = port;
>> + port->out_vq->vdev_priv = port;
>>
>> fill_queue(port->in_vq, &port->inbuf_lock);
>>
>
> Let's add an API to set this pointer.
> Document that you must not set it after
> probe/restore returned.

Why?

> With an API we can actually have a BUG_ON that checks it's not modified
> after probe.
>
>> diff --git a/include/linux/virtio.h b/include/linux/virtio.h
>> index c193ccf..6b39c1a 100644
>> --- a/include/linux/virtio.h
>> +++ b/include/linux/virtio.h
>> @@ -14,6 +14,7 @@
>> * @callback: the function to call when buffers are consumed (can be NULL).
>> * @name: the name of this virtqueue (mainly for debugging)
>> * @vdev: the virtio device this queue was created for.
>> + * @vdev_priv: a pointer for the virtio device to use.
>
> It's for the driver actually.

Right. However...

>> * @priv: a pointer for the virtqueue implementation to use.
>> */
>> struct virtqueue {
>> @@ -21,6 +22,7 @@ struct virtqueue {
>> void (*callback)(struct virtqueue *vq);
>> const char *name;
>> struct virtio_device *vdev;
>> + void *vdev_priv;
>> void *priv;
>
> The name is confusing: it seems to imply it's a device pointer.

... it's private to the driver that owns vdev, hence the name.

> Maybe we should rename priv to something like __priv and make
> priv useful for devices?

I wanted to go for the smallest possible changes. Right now we have 1
user for each member (virtio-ring vs. virtio-console) so neither member
is really dominating.

Paolo


\
 
 \ /
  Last update: 2012-04-18 22:37    [W:0.187 / U:0.076 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site