In summary, events are reported using a per-domain shared event array
of event words. Each event word has PENDING, LINKED and MASKED bits
and a LINK field for pointing to the next event in the event queue.
There are 16 event queues (with different priorities) per-VCPU.
Key advantages of this new ABI include:
- Support for over 100,000 events (2^17).
- 16 different event priorities.
- Improved fairness in event latency through the use of FIFOs.
The ABI is available in Xen 4.4 and later.
Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>