quoted

quoted

An option vector (or dt-cpu-ftrs) could be defined to disable msgsndp
to get KVM performance back.

An option vector would require a PAPR change. Unless the architecture 
reserves some bits for the implementation, but I don't think so. Same
for CAS.

quoted

Qemu/KVM populates /proc/device-tree/hypervisor, so we *could* look at
that. Though adding PowerVM/KVM specific hacks is obviously a very
slippery slope.

QEMU could advertise a property "emulated-msgsndp", or something similar, 
which would be interpreted by Linux as a CPU feature and taken into account 
when doing the IPIs.

Could we remove msgsndp support from HFSCR in KVM and test it in pseries ? 

C.