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

[Gleb Natapov <gleb@redhat.com>]

On Wed, Oct 15, 2008 at 10:56:02AM -0500, Anthony Liguori wrote:
> Gleb Natapov wrote:
>> Andrew,
>>
>> On Wed, Oct 15, 2008 at 07:18:52AM -0700, Andrew Biggadike wrote:
>>   
>>> Gleb Natapov <gleb@redhat.com> wrote:
>>>     
>>>>> Of course, you should also take a look at VMware's VMCI.  If we're going
>>>>> to have a socket interface, if we can have a compatible userspace
>>>>> interface, that would probably be a good thing.
>>>>>         
>>>> I looked at what I could find about VMCI (http://pubs.vmware.com/vmci-sdk/index.html).
>>>>       
>>> I believe Anthony intended for you to look at the sockets interface to
>>> VMCI: http://www.vmware.com/pdf/ws65_s2_vmci_sockets.pdf.
>>>
>>>     
>> Using VMCI socket requires loading kernel module in a guest and in a host.
>> Is this correct?
>>   
>
> Note that their addressing scheme uses a CID/port pair.  I think it's  
> interesting and somewhat safe because it basically mirrors an IP/port  
> pair.  That makes it relatively safe because that addressing mechanism  
> is well known (with it's advantages and flaws).  For instance, you need  
> some sort of authority to assign out ports.  It doesn't really help with  
> discovery either.
>
I fails to see how this is more safe that what I propose. Same problem
exactly: which ID/port to use for my service? But I also don't want to
compare proposed vmchannel and VMCI socket. They try to solve different
problems as far as I can see. VMCI tries to address intra host communication
performance problem (what about migration of a guest using it BTW? Or
security? Firewalls know nothing about it). vmchannel goal is to provide
management tools a way to communicate with in guest agents.

--
			Gleb.