I'd like to see if we can create a pattern in upstream Kata Containers to help facilitate directly assigning volumes to the VM via virtio-blk, skipping any mounts on the host, and avoiding needing to use a shared file-system for the particular volume. Some of the benefits in doing this:

 - we can better isolate the host (no mounted filesystem),

 - more efficient and much faster data path that non-dax virtiofs.

 - avoid inode caching/memory overheads of virtiofs on the host.

In Kubernetes today, there is not a direct communication channel between CSI and the runtime. To make this work on a shorter timeline, therefore, we need to come up with a less traditional way to communicate between the user, CSI and the runtime. I have a proposal in place that "works" today, and I'd like to get feedback on how to improve it, and see if it could be a good fit for upstream. Please see: the proposal at [1], and the PR associated with that proposal at [2].

Please let me know if you:

  - have any suggestions on the pattern

  - you are a user that would find this pattern helpful for their use-cases

Thanks,

Eric

[1] - https://github.com/egernst/kata-containers/blob/da-proposal/docs/design/direct-assign-volume.md

[2] - https://github.com/kata-containers/kata-containers/pull/1568