[kata-dev] vsock & network namespaces in Kata

Stefano Garzarella sgarzare at redhat.com
Wed Dec 4 17:05:58 UTC 2019

On Wed, Dec 04, 2019 at 03:54:06PM +0000, Montes, Julio wrote:
> Hi Stefano

Hi Julio

> > - Host: assign the same CID of VMs running in different network
> >  namespaces
> this means two VMs running in different namespace can use the same CID?


> currently we use VHOST_VSOCK_SET_GUEST_CID to get a unique context ID, is this going to change?

The only change is that the CID is unique in the network namespace

> > 1. Is the VMM (e.g. QEMU) running in a network namespace?
> yes, see https://github.com/kata-containers/runtime/blob/62cd08044d78912228d9dc800cb1b8bd3de3b971/virtcontainers/sandbox.go#L1024-L1041
> > 2. Is the host application, that use vsock to communicate with the
> >   guest, running in the same network namespace?
> afaik, no

This could be a problem with the RFC that I sent, because we allow only
the processes in the same netns of the VMM, to communicate with the

Do you think could be an easy change in the Kata runtime?
I need to look better, but if you already know the answer you'll
save me some time :)

> > 3. Is the agent in the guest running outside a netns (default init_netns)?
> yes

This is nice.

Thank you very much,

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