vhost-net: allow configuring extended features

Use the extended feature type for 'acked_features' and implement
two new ioctls operation allowing the user-space to set/query an
unbounded amount of features.

The actual number of processed features is limited by VIRTIO_FEATURES_MAX
and attempts to set features above such limit fail with
EOPNOTSUPP.

Note that: the legacy ioctls implicitly truncate the negotiated
features to the lower 64 bits range and the 'acked_backend_features'
field don't need conversion, as the only negotiated feature there
is in the low 64 bit range.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Paolo Abeni 2025-07-08 17:54:54 +02:00
commit 333c515d18
5 changed files with 82 additions and 23 deletions