Re: Does macvtap support host to guest communication?

[Asias He <asias.hejun@gmail.com>]

On 04/18/2011 11:05 PM, Arnd Bergmann wrote:
> On Monday 18 April 2011, Asias He wrote:
>> We do need "guest appearing on the same network as the host" support as
>> well. The reason I am considering using macvatp instead of tap plus
>> brctl is that it simplifies the bridge configuration and it is more
>> efficient.
> 
> Right, you certainly don't need to consider tap/brctl any more.
> 
>> However, IMHO, the interface of macvtap is not user friendly, at least
>> for me. I have no idea about the technical reasons that make the
>> low-level device inaccessible. But if it is accessible, a lot of
>> configuration can be eliminated. I know virtualbox's bridge mode has
>> this kind of restriction, while VMware's bridge mode does not.
> 
> The main reason is that having a MAC address scan in the regular
> networking core would make the common TX case where there is no
> macvlan device more complex. Macvtap is derived from the plain
> macvlan driver, which used to support only sending out to the
> wire until I added the optional bridge mode.
> 
> If you want a regular device to be able to send to a macvlan
> port, that would require at least these changes:
> 
> * Add an option to put a plain device into macvlan-bridge mode
> * Add support for that option into iproute2
> * Add a hook into dev_queue_xmit() to check for macvlan ports

Cool! Arnd, mind to add this feature to macvtap?

-- 
Best Regards,
Asias He