Re: [PATCH 5/7] x86/fpu: Change fpu->fpregs_active users to fpu->fpstate_active

From: Ingo Molnar
Date: Thu Jan 26 2017 - 11:23:32 EST

* Rik van Riel <riel@xxxxxxxxxx> wrote:

> Let me go totally reimplement this whole project in a different way...

Note that I can still be convinced about complicating the FPU state machine as
well if that ends up being the best approach for KVM - but it appears to me (from
a very superficial look) that turning vCPU threads into no-FPU kthreads or
representing the guest FPU state directly with the host FPU context would be even
more beneficial, from the simplicity and KVM performance POV?

> At least I found some good FPU bugs and cleanups along the way.

Absolutely, and your efforts are much appreciated! This ptrace state handling
madness that bit you on SkyLake was something I missed entirely.