On Tue, Sep 15, 2026 at 10:43:23AM -0700, Bobby Eshleman wrote:
On Tue, Sep 15, 2026 at 12:16:47PM +0200, Stefano Garzarella wrote:
On Fri, Sep 04, 2026 at 10:30:28AM -0700, Bobby Eshleman wrote:
> On Fri, Sep 04, 2026 at 10:55:17AM +0200, Stefano Garzarella wrote:
> > On Wed, Sep 02, 2026 at 04:00:46PM -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.
> >
> > Thanks for this, I'll do a proper review next week, in the mean time some
> > comments below:
> >
> > >
> > > This series lets a guest move that device into a network namespace. A
> > > new ioctl on /dev/vsock, IOCTL_VM_SOCKETS_ASSIGN_G2H_NETNS, assigns the
> > > device to the namespace of the calling process. The namespace's existing
> >
> > Why an ioctl?
> >
> > I'm asking because I'd like to know if you've already considered any
> > alternatives (sysfs, netlink, etc.)
> >
> > How do you think the ioctl should be used? Should we provide an userspace
> > tool, or extending some existing tools?
> >
> > Thanks,
> > Stefano
>
> Really only because /dev/vsock exists and the prior series used it.
Yeah, I vaguely remember that we may have discussed switching to netlink in
that thread, but I can't find it.
>
> Considering netlink, it might be the better option because there is a
> lot of prior art solving problems we might have in the future. For
> example, I was thinking about when users suddenly lose access to vsock,
> with just the current assign ioctl there is no way for apps or users to
> figure out why this happened. We can have an ioctl() setter for user,
> but in netdev world users can actually get a notification via netlink as
> to which namespace the device went to and what its ifindex is there (see
> __dev_change_net_namespace() for the RTM_DELLINK and RTM_NEWLINK
> messages). There is probably more, but that's the case that comes to
> mind.
netlink seems like the right way to go, do you think it'll be a real pain to
implement?
It is really not bad... it'll include a yaml spec in
Documentation/netlink/specs/ of call names and perms, a new target for
generated code in the Makefile, a handler, and then
tools/net/ynl/ynl-regen.sh generates the plumbing.
Ah, nice! So, do you want to try that direction?
Thanks,
Stefano
