Re: [PATCH 1/5] powerpc/pseries: do not use msgsndp doorbells on POWER9 guests

On Mon, 2017-04-10 at 13:22 +1000, Nicholas Piggin wrote:

On Sun, 09 Apr 2017 18:03:35 +1000

quoted

Benjamin Herrenschmidt [off-list ref] wrote:

quoted

On Fri, 2017-04-07 at 22:55 +1000, Nicholas Piggin wrote:

quoted

POWER9 hypervisors will not necessarily run guest threads together on
the same core at the same time, so msgsndp should not be used.  

Maybe we shouldn't advertise doorbells at all ?

Possibly not. I don't know if there is a good way to switch it off
in the guest from the host with device tree currently. Might be better
to clear it early in the guest rather than test it here though?

Sure for now. Long term a separate DT entry would be good. Might be
worth re-enabling one day if we have HW virtualization of geust
doorbells.

Cheers,
Ben