Re: Upstream QEMU based stubdom and rump kernel

[Antti Kantee <pooka@iki.fi>]

On 19/03/15 08:48, Martin Lucina wrote:
> By "faking out" Anil means a shim to get existing applications
> which currently use PF_UNIX (and possibly PF_INET, though that will be
> harder to fake) to use the hypervisor bus to talk to another colocated
> unikernel instead.
>
> The motivations for this are:
>
> - Taking the TCP stack out of the picture entirely for intra-unikernel
>    comms (eg. PHP unikernel <-> MySQL unikernel). Both of those could be
>    thus be linked without the PF_INET component.
> - This means that you do not need to set up and manage a TCP network in
>    your infrastructure for intra-unikernel comms, which is a huge advantage
>    from an operations point of view.
> - It also means that unikernels which should not be talking TCP to
>    anywhere, ever, can't do that.

Aah, ic, you want to do what rumpnet_sockin does, except use the 
hypervisor bus instead of an external sockets-like networking facility 
like sockin does.

rumpnet_sockin was indeed originally developed so that you wouldn't need 
to include the full TCP/IP stack in a rump kernel, which is nice for 
scenarios where you want to do networking without configuring anything 
for each guest instance; running the kernel NFS client in userspace and 
using the host's network was the original use case.

Yea, that'll just work on the rump kernel side for PF_INET/PF_INET6 
(though you might have to do a bit more handling in your "fake" driver). 
  Not sure what doing the same for PF_UNIX would entail, if anything 
special, but only one way to find out.

   - antti