On Thu, Jul 04, 2024 at 01:06:12PM +0200, Jiri Pirko wrote:
> Thu, Jul 04, 2024 at 09:47:09AM CEST, mst@xxxxxxxxxx wrote:
> >On Thu, Jul 04, 2024 at 08:43:35AM +0200, Jiri Pirko wrote:
> >> From: Jiri Pirko <jiri@xxxxxxxxxx>
> >>
> >> Introduce a structure virtio_queue_info to carry name, callback and ctx
> >> together. In order to allow config implementations to accept config op
> >> with array of virtio_queue_info structures, introduce a new
> >> find_vqs_info() op. Do the needed conversion in virtio_find_vqs_ctx().
> >> Note that whole virtio_find_vqs_ctx() is going to be eventually removed
> >> at the and of this patchset.
> >>
> >> Signed-off-by: Jiri Pirko <jiri@xxxxxxxxxx>
> >> ---
> >> v1->v2:
> >> - fixed comments for struct virtqueue_info
> >> - s/virtio_queue_info/virtqueue_info/
> >> ---
> >> include/linux/virtio_config.h | 51 ++++++++++++++++++++++++++++++++---
> >> 1 file changed, 48 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
> >> index 82a1d798b2f1..9b975c2830f6 100644
> >> --- a/include/linux/virtio_config.h
> >> +++ b/include/linux/virtio_config.h
> >> @@ -18,6 +18,16 @@ struct virtio_shm_region {
> >>
> >> typedef void vq_callback_t(struct virtqueue *);
> >>
> >> +struct virtqueue_info {
> >> + const char *name; /* Mainly for debugging, may be NULL for a virtqueue
> >> + * unused by driver.
> >> + */
> >> + vq_callback_t *callback; /* May be NULL for vq that does
> >> + * not need a callback.
> >> + */
> >> + bool ctx;
> >
> >
> > /*
> > * Always
> > * like this
> > * outside of netdev code
> > * and it comes before the code being documented
> > */
> >
> > /* Never
> > * like this
> > */
>
>
> How about to properly document the struct instead like this:
> /**
> * struct virtqueue_info - info for a virtqueue passed to find_vqs()
> * @name: mainly for debugging, NULL for a virtqueue
> * unused by the driver
> * @callback: NULL for a virtqueue that does not need a callback
> * @ctx: true to allow to maintain extra context per virtqueue
> */
> struct virtqueue_info {
> const char *name;
> vq_callback_t *callback;
> bool ctx;
> };
Sure. And actually include the explanation what the fields are then?
@name: virtqueue description
@callback: a callback to invoke on a used buffer notification
>
>
> >
> >
> >Also "may be null" is a bit confusing - it has to be null
> >for such a vq.
> >
> >Thus:
> >
> > /*
> > * name: mainly for debugging, NULL for a virtqueue
> > * unused by the driver.
> > */
> > const char *name;
> >
> >and similarly for the callback.
> >
> >
> >
> >> +};
> >> +
> >> /**
> >> * struct virtio_config_ops - operations for configuring a virtio device
> >> * Note: Do not assume that a transport implements all of the operations
> >> @@ -58,6 +68,12 @@ typedef void vq_callback_t(struct virtqueue *);
> >> * names: array of virtqueue names (mainly for debugging)
> >> * include a NULL entry for vqs unused by driver
> >> * Returns 0 on success or error status
> >> + * @find_vqs_info: find virtqueues and instantiate them.
> >> + * vdev: the virtio_device
> >> + * nvqs: the number of virtqueues to find
> >> + * vqs: on success, includes new virtqueues
> >> + * vqs_info: array of virtqueue info structures
> >> + * Returns 0 on success or error status
> >> * @del_vqs: free virtqueues found by find_vqs().
> >> * @synchronize_cbs: synchronize with the virtqueue callbacks (optional)
> >> * The function guarantees that all memory operations on the
> >> @@ -109,6 +125,10 @@ struct virtio_config_ops {
> >> struct virtqueue *vqs[], vq_callback_t *callbacks[],
> >> const char * const names[], const bool *ctx,
> >> struct irq_affinity *desc);
> >> + int (*find_vqs_info)(struct virtio_device *vdev, unsigned int nvqs,
> >> + struct virtqueue *vqs[],
> >> + struct virtqueue_info vqs_info[],
> >> + struct irq_affinity *desc);
> >> void (*del_vqs)(struct virtio_device *);
> >> void (*synchronize_cbs)(struct virtio_device *);
> >> u64 (*get_features)(struct virtio_device *vdev);
> >> @@ -117,7 +137,7 @@ struct virtio_config_ops {
> >> int (*set_vq_affinity)(struct virtqueue *vq,
> >> const struct cpumask *cpu_mask);
> >> const struct cpumask *(*get_vq_affinity)(struct virtio_device *vdev,
> >> - int index);
> >> + int index);
> >> bool (*get_shm_region)(struct virtio_device *vdev,
> >> struct virtio_shm_region *region, u8 id);
> >> int (*disable_vq_and_reset)(struct virtqueue *vq);
> >> @@ -210,14 +230,39 @@ static inline bool virtio_has_dma_quirk(const struct virtio_device *vdev)
> >> return !virtio_has_feature(vdev, VIRTIO_F_ACCESS_PLATFORM);
> >> }
> >>
> >> +static inline
> >> +int virtio_find_vqs_info(struct virtio_device *vdev, unsigned int nvqs,
> >> + struct virtqueue *vqs[],
> >> + struct virtqueue_info vqs_info[],
> >> + struct irq_affinity *desc)
> >> +{
> >> + return vdev->config->find_vqs_info(vdev, nvqs, vqs, vqs_info, desc);
> >> +}
> >> +
> >> static inline
> >> int virtio_find_vqs_ctx(struct virtio_device *vdev, unsigned nvqs,
> >> struct virtqueue *vqs[], vq_callback_t *callbacks[],
> >> const char * const names[], const bool *ctx,
> >> struct irq_affinity *desc)
> >> {
> >> - return vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names, ctx,
> >> - desc);
> >> + struct virtqueue_info *vqs_info;
> >> + int err, i;
> >> +
> >> + if (!vdev->config->find_vqs_info)
> >> + return vdev->config->find_vqs(vdev, nvqs, vqs, callbacks,
> >> + names, ctx, desc);
> >> +
> >> + vqs_info = kmalloc_array(nvqs, sizeof(*vqs_info), GFP_KERNEL);
> >> + if (!vqs_info)
> >> + return -ENOMEM;
> >> + for (i = 0; i < nvqs; i++) {
> >> + vqs_info[i].name = names[i];
> >> + vqs_info[i].callback = callbacks[i];
> >> + vqs_info[i].ctx = ctx ? ctx[i] : false;
> >> + }
> >> + err = virtio_find_vqs_info(vdev, nvqs, vqs, vqs_info, desc);
> >> + kfree(vqs_info);
> >> + return err;
> >> }
> >>
> >> static inline
> >> --
> >> 2.45.2
> >
