[Qemu-devel] Remote guest VBD

[Kaushik Bhandankar <kaushikb@cc.gatech.edu>]

Hello,

I  am trying to implement remote VBD functionality for HVM guests is 
fully-virtualized Xen 3.0 unstable.

Consider 2 machines: machine 1 and machine 2, booth Intel-VT capable 
machines hosting fully-virtualized Xen 3.0-unstable.

Lets say the HVM guest sitting on machine 1 has its VBD located on 
machine 2 (same/different LAN)

For this, I have established a 9P communication channel (similar to 
socket communication) between the Dom0's of machine 1 and machine 2 with 
the 9P server thread running on machine 2 and 9P client thread running 
on machine 1.

Whenever the HVM guest tries to access its VBD, my 9P client needs 
tointercept this invocation and send it to the 9P server which does the 
necessary stuff with the VBD and sends back the response to the 9P client.

But I am not sure about following details:
1) The code path followed when a guest tries to access its VBD before it 
lands me into tools/ioemu/hw/ide.c:ide_ioport_read() or 
tools/ioemu/hw/ide.c:ide_ioport_write()
2) Where exactly should the 9P client intercept the call by guest to 
access its VBD?
3) When the 9P server sends the response back to the 9P client, how 
should this response be forwarded by the client?

Any help about this will be appreciated.

-Kaushik