[Xen-users] Packet flow in Xen

[Siddharth Wagh <swagh@xxxxxxxxxxxxxxxx>]

Hello all,

I am trying to understand the underlying mechanism behind how exactly the packet flows in a Xen virtualized system. There are some gaps in my knowledge that need to be filled.

Guest --> Internet:

1. Guest writes request on I/O ring buffers in hypervisor (using netfront.c)
2. Guest writes notification in grant tables in XenStore using event channels.
3. Dom-0 reads grant reference and locates/reads request from ring buffer (using netback.c)

4. Packet is bridged using Xenbr0 (created by network-bridge & vif-bridge to pass through peth0 (ebtables module).
5. There is interaction between real device driver in Dom-0 and NIC and packet is probably sent from ring buffers on the Internet using DMA.

I know there are lot of loopholes here, and I would really appreciate if someone could help me grasp the exact scenario, especially referring to scripts that carry out the process.

Thanks & Regards,
Sid


_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users