Re: inter-VM communication?

[Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>]

Jun Koi wrote:
> On 11/30/06, Dor Laor <dor.laor-atKUWr5tajBWk0Htik3J/w@public.gmane.org> wrote:
>   
>>> Hi,
>>>
>>> Do we have any inter-VM communication technique in KVM (something for
>>> example like event-channel in Xen) ?
>>>
>>> Thanks,
>>> Jun
>>>       
>> Currently there is full isolation of the guests.
>> Such mechanism would not be complicated to add since we anyway map
>> memory from user space & inject interrupt from there also.
>> Do you have any specific interest in inter VM channel?
>>     
>
> I want to exchange some data between a VM and hypervisor. One solution
> is to map some memory of that VM (from hypervisor), and read/write
> data thru that memory area. However, I need to a mechanism to notify
> the other partner when data is ready to read/write.
>
> Without any inter-VM communication mechanism, I dont see any clean way
> to achieve this. Any idea?
>   

Write a pci device for qemu to do what you want.  The pci device can 
communicate through a unix domain socket, shared memory, or any other 
ipc mechanism with any other process on the host (including other 
virtual machines).

Guest->host communication is performed by writing the device's mmio 
registers.  Host->guest communications are done by raising a virtual 
interrupt.

-- 
error compiling committee.c: too many arguments to function


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