[PATCH net-next v1 0/3] vsock: Add flag field in the vsock address

[Andra Paraschiv <andraprs@amazon.com>]

vsock enables communication between virtual machines and the host they are
running on. Nested VMs can be setup to use vsock channels, as the multi
transport support has been available in the mainline since the v5.5 Linux kernel
has been released.

Implicitly, if no host->guest vsock transport is loaded, all the vsock packets
are forwarded to the host. This behavior can be used to setup communication
channels between sibling VMs that are running on the same host. One example can
be the vsock channels that can be established within AWS Nitro Enclaves
(see Documentation/virt/ne_overview.rst).

To be able to explicitly mark a connection as being used for a certain use case,
add a flag field in the vsock address data structure. The "svm_reserved1" field
has been repurposed to be the flag field. The value of the flag will then be
taken into consideration when the vsock transport is assigned.

This way can distinguish between nested VMs / local communication and sibling
VMs use cases. And can also setup one or more types of communication at the same
time.

Thank you.

Andra

---

Patch Series Changelog

The patch series is built on top of v5.10-rc6.

GitHub repo branch for the latest version of the patch series:

* https://github.com/andraprs/linux/tree/vsock-flag-sibling-comm-v1

---

Andra Paraschiv (3):
  vm_sockets: Include flag field in the vsock address data structure
  virtio_transport_common: Set sibling VMs flag on the receive path
  af_vsock: Assign the vsock transport considering the vsock address
    flag

 include/uapi/linux/vm_sockets.h         | 18 +++++++++++++++++-
 net/vmw_vsock/af_vsock.c                | 15 +++++++++++----
 net/vmw_vsock/virtio_transport_common.c |  8 ++++++++
 3 files changed, 36 insertions(+), 5 deletions(-)

-- 
2.20.1 (Apple Git-117)




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