Re: [PATCH net-next v4 0/7] vsock: assign the guest vsock device to a network namespace

[Bobby Eshleman <bobbyeshleman@meta.com>]

On Wed, Oct 21, 2026 at 11:48:30AM +0200, Stefano Garzarella wrote:
> On Tue, Oct 20, 2026 at 06:15:03PM -0700, Bobby Eshleman wrote:
> > vsock network namespaces let a host put each VM in a namespace of its
> > own. A guest has no equivalent yet. It has a single G2H device that
> > cannot be assigned to a network namespace.
> > 
> > This series lets a guest move that device into a network namespace. A
> > new generic netlink family, "vsock", supports the command
> > VSOCK_CMD_DEV_NETNS_SET which assigns the device to the namespace the
> > request was sent from. The namespace's existing ns_mode then decides who
> > may use it: a "global" namespace shares the device with every other
> > global namespace, and a "local" namespace keeps the host connection to
> > itself. The device starts out in the initial namespace, so until the
> > command is issued nothing has moved and no mode has changed. There is no
> > explicit unassign as assigning the device back to the initial namespace
> > is equivalent.
> > 
> > The command requires CAP_NET_ADMIN in the initial user namespace, so
> > that an unprivileged user namespace cannot claim the device.
> > 
> > Connections that can no longer reach the device after a move are reset,
> > so that a namespace which has lost access cannot keep using a socket it
> > opened while it still had access. The assignment holds a reference on
> > the namespace, so deleting that namespace does not move the device; only
> > another assignment does.
> > 
> > Transports opt in through a new netns_assign_allow flag. Only
> > virtio-vsock sets it here, because it is the only guest transport
> > that I am able to test against.
> > 
> > Based off of Stefano's original series:
> > https://lore.kernel.org/all/20200116172428.311437-1-sgarzare@redhat.com/
> > 
> > Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
> > Link: https://lore.kernel.org/all/20200427142518.uwssa6dtasrp3bfc@steredhat/
> > Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
> > ---
> > Changes in v4:
> > - All Sashiko fixes (see individual patch change lists)
> > - Link to v3: https://lore.kernel.org/r/20261012-vsock-guest-ns-v3-0-b32447c66b23@meta.com
> > 
> 
> Sorry, yesterday I started to review v3, but didn't post comments :-(
> I'll send on this series.
> 
> Thanks,
> Stefano

Hey Stefano, no problem. Sashiko kept me pretty busy. Hopefully we
landed in a better position for your review.

Best,
Bobby