Disk IO using QEMU

[Alkesh Shah <salkesh@cc.gatech.edu>]

Hi,

I am trying to understand how Disk I/O actually works in HVM. From what 
I understand, whenever a disk i/o takes place in a guest OS, a VMEXIT 
occurs. The hypervisor than executes some handler, which sets up an 
event pending bit for the event channel communicating with the QEMU-DM 
in the Domain 0. QEMU-DM than emulates these I/O instructions.

Specifically, I wanted to know -
1. The functions that are called in this process....  or the files that 
I need to look at in order to understand the exact flow.
2. Since, QEMU-DM handles both the display as well as the disk I/O, is 
the same event channel port used for communication between hypervisor 
and qemu-dm for both display and disk i/o?

Thank you for you help.

Regards,
Alkesh Shah