Re: [RFC PATCH 08/16] x86/xen: irq/upcall handling with multiple xenhosts

From: Juergen Gross
Date: Fri Jun 14 2019 - 08:06:03 EST


On 09.05.19 19:25, Ankur Arora wrote:
For configurations with multiple xenhosts, we need to handle events
generated from multiple xenhosts.

Having more than one upcall handler might be quite hairy, and it would
be simpler if the callback from L0-Xen could be bounced via L1-Xen.
This will also mean simpler pv_irq_ops code because now the IF flag
maps onto the xh_default->vcpu_info->evtchn_upcall_mask.

However, we still update the xh_remote->vcpu_info->evtchn_upcall_mask
on a best effort basis to minimize unnecessary work in remote xenhost.

This is another design decision yet to be taken.

My current prefernce is L1 Xen mapping events from L0 to L1 guest
events.


Juergen