Re: Thoughts of AMX KVM support based on latest kernel

From: Paolo Bonzini
Date: Wed Nov 17 2021 - 07:53:58 EST

On 11/17/21 11:15, Tian, Kevin wrote:
We are not sure whether such trick is worthwhile, since a sane
guest shouldn't set XFD[AMX]=1 before storing the AMX state. This
is why we want to seek SDM change to mark out that the software
should not assume XTILEDATA is still valid when XFD[AMX]=1.

Okay, I just don't want it to be called out as virtualization specific.

It doesn't have to happen in current processors, but it should be architecturally valid behavior to clear the processor's state as soon as a bit in XFD is set to 1.