virtio: Features change to 64 bit in all virtio_dispatch

[wyr-7]

change all 32 bit features to 64 bit for adapt more features

[arnopo]

regarding virtio spec 64 bits could be not enough. If we update this I would be in favour of having a "features word selection index" as done in virtio mmio transport would be more reliable.
This imply to create new APIs and deprecate exiting ones...

For instance

static inline uint32_t
rpmsg_virtio_get_features_by_idx(struct rpmsg_virtio_device *rvdev, unint32 word_idx)

[CV-Bowen]

@arnopo Hi, from the virtio spec v1.3, the 64 bits is enough for now and linux use uint64_t to represent the feature bit too. Does Linux plan to update to "features word selection index" APIs in the future?

[arnopo]

I don't know if Linux plans to do it. What I can see is that the virtio spec defines the feature bits in this way:

• 0 to 23, and 50 to 127
  Feature bits for the specific device type

• 24 to 40
  Feature bits reserved for extensions to the queue and feature negotiation mechanisms

• 41 to 49, and 128 and above
  Feature bits reserved for future extensions.

The virtio MMIO transport layer also supports an infinite number of feature bits

So as this PR update the API i would prefer to directly address it instead of implementing an intermediate step that update the API

I don't know if Linux plan to do it, what I can see is that it is that the virtio spec define the feature bits in this way:

• 0 to 23, and 50 to 127
  Feature bits for the specific device type

• 24 to 40
  Feature bits reserved for extensions to the queue and feature negotiation mechanisms

• 41 to 49, and 128 and above
  Feature bits reserved for future extensions.

The virtio MMIO transport layer also supports an infinite number of feature bits.

So, as this PR updates the API, I would prefer to directly address it instead of implementing an intermediate step that also need an update of the API.

[CV-Bowen]

@arnopo Thanks, as you said, it would be better to use "features word selection index" method to support feature bits larger than 64 bits and we will update this PR.

[github-actions]

This pull request has been marked as a stale pull request because it has been open (more than) 45 days with no activity.