Re: [PATCH net-next v16 00/12] vsock: add namespace support to vhost-vsock and loopback

[Stefano Garzarella <sgarzare@redhat.com>]

On Wed, Jan 21, 2026 at 02:11:40PM -0800, Bobby Eshleman wrote:
>This series adds namespace support to vhost-vsock and loopback. It does
>not add namespaces to any of the other guest transports (virtio-vsock,
>hyperv, or vmci).
>
>The current revision supports two modes: local and global. Local
>mode is complete isolation of namespaces, while global mode is complete
>sharing between namespaces of CIDs (the original behavior).
>
>The mode is set using the parent namespace's
>/proc/sys/net/vsock/child_ns_mode and inherited when a new namespace is
>created. The mode of the current namespace can be queried by reading
>/proc/sys/net/vsock/ns_mode. The mode can not change after the namespace
>has been created.
>
>Modes are per-netns. This allows a system to configure namespaces
>independently (some may share CIDs, others are completely isolated).
>This also supports future possible mixed use cases, where there may be
>namespaces in global mode spinning up VMs while there are mixed mode
>namespaces that provide services to the VMs, but are not allowed to
>allocate from the global CID pool (this mode is not implemented in this
>series).
>
>Additionally, added tests for the new namespace features:
>
>tools/testing/selftests/vsock/vmtest.sh
>1..25
>ok 1 vm_server_host_client
>ok 2 vm_client_host_server
>ok 3 vm_loopback
>ok 4 ns_host_vsock_ns_mode_ok
>ok 5 ns_host_vsock_child_ns_mode_ok
>ok 6 ns_global_same_cid_fails
>ok 7 ns_local_same_cid_ok
>ok 8 ns_global_local_same_cid_ok
>ok 9 ns_local_global_same_cid_ok
>ok 10 ns_diff_global_host_connect_to_global_vm_ok
>ok 11 ns_diff_global_host_connect_to_local_vm_fails
>ok 12 ns_diff_global_vm_connect_to_global_host_ok
>ok 13 ns_diff_global_vm_connect_to_local_host_fails
>ok 14 ns_diff_local_host_connect_to_local_vm_fails
>ok 15 ns_diff_local_vm_connect_to_local_host_fails
>ok 16 ns_diff_global_to_local_loopback_local_fails
>ok 17 ns_diff_local_to_global_loopback_fails
>ok 18 ns_diff_local_to_local_loopback_fails
>ok 19 ns_diff_global_to_global_loopback_ok
>ok 20 ns_same_local_loopback_ok
>ok 21 ns_same_local_host_connect_to_local_vm_ok
>ok 22 ns_same_local_vm_connect_to_local_host_ok
>ok 23 ns_delete_vm_ok
>ok 24 ns_delete_host_ok
>ok 25 ns_delete_both_ok
>SUMMARY: PASS=25 SKIP=0 FAIL=0
>
>Thanks again for everyone's help and reviews!

Thank you for your hard work and patience!

I think we've come up with an excellent solution that's also not too 
invasive.

All the patches have my R-b, I've double-checked and tested this v16.
Everything seems to be working fine (famous last words xD).

So this series is good to go IMO!

Next step should be to update the vsock(7) namespace.

Thanks,
Stefano