Re: [PATCH][RFC] vmchannel a data channel between host and guest.

[Anthony Liguori <anthony@codemonkey.ws>]

Gleb Natapov wrote:
> Hello,
>
>  Sometimes there is a need to pass various bits of information between host
> and guest (mostly for management purposes such as host screen resolution
> changes or runtime statistics of a guest). To do that we need some way to
> pass data between host and guest. Attached patch implements vmchannel that can
> be used for this purpose. It is based on virtio infrastructure and
> support more then one channel. The vmchannel presents itself as PCI
> device to a guest so guest driver is also required. The one for linux is
> attached. It uses netlink connector to communicate with userspace.
>   

Essentially, the transport itself ends up looking very much like a 
network device so the only real design question is what the guest and 
host interfaces look like.  I don't know that a netlink interface is the 
best interface to userspace.  Why not a full blown socket?  Perhaps a 
virtual file system?

Having a limit of only 4 links seems like a problem to me too.

I think there needs to be a better articulation about why other 
interfaces cannot be used (like a network device).  Is it because of 
ease of guest configuration?  Is it performance?

Regards,

Anthony Liguori

> Comments are welcome.
>
> --
> 			Gleb.
>