On Wed, Mar 05, 2025 at 10:23:08AM +0100, Stefano Garzarella wrote: > On Wed, 5 Mar 2025 at 08:32, Michael S. Tsirkin <mst@xxxxxxxxxx> wrote: > > > > On Thu, Jan 16, 2020 at 06:24:26PM +0100, Stefano Garzarella wrote: > > > This patch adds a check of the "net" assigned to a socket during > > > the vsock_find_bound_socket() and vsock_find_connected_socket() > > > to support network namespace, allowing to share the same address > > > (cid, port) across different network namespaces. > > > > > > This patch adds 'netns' module param to enable this new feature > > > (disabled by default), because it changes vsock's behavior with > > > network namespaces and could break existing applications. > > > G2H transports will use the default network namepsace (init_net). > > > H2G transports can use different network namespace for different > > > VMs. > > > > > > I'm not sure I understand the usecase. Can you explain a bit more, > > please? > > It's been five years, but I'm trying! > We are tracking this RFE here [1]. > > I also add Jakub in the thread with who I discussed last year a possible > restart of this effort, he could add more use cases. > > The problem with vsock, host-side, currently is that if you launch a VM > with a virtio-vsock device (using vhost) inside a container (e.g., > Kata), so inside a network namespace, it is reachable from any other > container, whereas they would like some isolation. Also the CID is > shared among all, while they would like to reuse the same CID in > different namespaces. > > This has been partially solved with vhost-user-vsock, but it is > inconvenient to use sometimes because of the hybrid-vsock problem > (host-side vsock is remapped to AF_UNIX). > > Something from the cover letter of the series [2]: > > As we partially discussed in the multi-transport proposal, it could > be nice to support network namespace in vsock to reach the following > goals: > - isolate host applications from guest applications using the same ports > with CID_ANY > - assign the same CID of VMs running in different network namespaces > - partition VMs between VMMs or at finer granularity > > Thanks, > Stefano > > [1] https://gitlab.com/vsock/vsock/-/issues/2 > [2] https://lore.kernel.org/virtualization/20200116172428.311437-1-sgarzare@xxxxxxxxxx/ Ok so, host side. I get it. And the problem with your patches is that they affect the guest side. Fix that, basically. -- MST
