On Mon, 7 Feb 2022 14:45:02 +0800, Jason Wang <jasowang@xxxxxxxxxx> wrote:
>
> 在 2022/1/26 下午3:35, Xuan Zhuo 写道:
> > Performing reset on a queue is divided into two steps:
> >
> > 1. reset_vq: reset one vq
> > 2. enable_reset_vq: re-enable the reset queue
> >
> > In the first step, these tasks will be completed:
> > 1. notify the hardware queue to reset
> > 2. recycle the buffer from vq
> > 3. release the ring of the vq
> >
> > The second step is similar to find vqs,
>
>
> Not sure, since find_vqs will usually try to allocate interrupts.
>
>
Yes.
> > passing parameters callback and
> > name, etc. Based on the original vq, the ring is re-allocated and
> > configured to the backend.
>
>
> I wonder whether we really have such requirement.
>
> For example, do we really have a use case that may change:
>
> vq callback, ctx, ring_num or even re-create the virtqueue?
1. virtqueue is not recreated
2. ring_num can be used to modify ring num by ethtool -G
There is really no scene to modify vq callback, ctx, name.
Do you mean we still use the old one instead of adding these parameters?
Thanks.
>
> Thanks
>
>
> >
> > So add two callbacks reset_vq, enable_reset_vq to struct
> > virtio_config_ops.
> >
> > Add a structure for passing parameters. This will facilitate subsequent
> > expansion of the parameters of enable reset vq.
> > There is currently only one default extended parameter ring_num.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> > ---
> > include/linux/virtio_config.h | 43 ++++++++++++++++++++++++++++++++++-
> > 1 file changed, 42 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
> > index 4d107ad31149..51dd8461d1b6 100644
> > --- a/include/linux/virtio_config.h
> > +++ b/include/linux/virtio_config.h
> > @@ -16,6 +16,44 @@ struct virtio_shm_region {
> > u64 len;
> > };
> >
> > +typedef void vq_callback_t(struct virtqueue *);
> > +
> > +/* virtio_reset_vq: specify parameters for queue_reset
> > + *
> > + * vdev: the device
> > + * queue_index: the queue index
> > + *
> > + * free_unused_cb: callback to free unused bufs
> > + * data: used by free_unused_cb
> > + *
> > + * callback: callback for the virtqueue, NULL for vq that do not need a
> > + * callback
> > + * name: virtqueue names (mainly for debugging), NULL for vq unused by
> > + * driver
> > + * ctx: ctx
> > + *
> > + * ring_num: specify ring num for the vq to be re-enabled. 0 means use the
> > + * default value. MUST be a power of 2.
> > + */
> > +struct virtio_reset_vq;
> > +typedef void vq_reset_callback_t(struct virtio_reset_vq *param, void *buf);
> > +struct virtio_reset_vq {
> > + struct virtio_device *vdev;
> > + u16 queue_index;
> > +
> > + /* reset vq param */
> > + vq_reset_callback_t *free_unused_cb;
> > + void *data;
> > +
> > + /* enable reset vq param */
> > + vq_callback_t *callback;
> > + const char *name;
> > + const bool *ctx;
> > +
> > + /* ext enable reset vq param */
> > + u16 ring_num;
> > +};
> > +
> > /**
> > * virtio_config_ops - operations for configuring a virtio device
> > * Note: Do not assume that a transport implements all of the operations
> > @@ -74,8 +112,9 @@ struct virtio_shm_region {
> > * @set_vq_affinity: set the affinity for a virtqueue (optional).
> > * @get_vq_affinity: get the affinity for a virtqueue (optional).
> > * @get_shm_region: get a shared memory region based on the index.
> > + * @reset_vq: reset a queue individually
> > + * @enable_reset_vq: enable a reset queue
> > */
> > -typedef void vq_callback_t(struct virtqueue *);
> > struct virtio_config_ops {
> > void (*enable_cbs)(struct virtio_device *vdev);
> > void (*get)(struct virtio_device *vdev, unsigned offset,
> > @@ -100,6 +139,8 @@ struct virtio_config_ops {
> > int index);
> > bool (*get_shm_region)(struct virtio_device *vdev,
> > struct virtio_shm_region *region, u8 id);
> > + int (*reset_vq)(struct virtio_reset_vq *param);
> > + struct virtqueue *(*enable_reset_vq)(struct virtio_reset_vq *param);
> > };
> >
> > /* If driver didn't advertise the feature, it will never appear. */
>
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