RE: [patch 13/31] x86/fpu: Move KVMs FPU swapping to FPU core

Liu, Jing2
2021-10-14T08:21:08Z

> > 1. KVM dynamic allocation API:
> > Since KVM also uses dynamic allocation, after KVM detects guest
> > requesting AMX by #NM trap, KVM need alloc extra buffer for this
> > vcpu's current->thread.fpu.fpstate and guest_fpu related.
> > So far, the kernel itself has such API like fpstate_realloc(), but
> > it's static. How about making a common function usable for KVM?
>
> Just making that function usable without a proper design how this should
> work at all does not solve anything.
>
> We first need a conclusion vs. buffer reallocation.
>
> Once that is sorted then we can create proper infrastructure for that in the
> FPU core code and not just expose a random function to KVM and hack it into
> submssion.
Yes, we need a consensus on the way we choose and then to see if need a
kernel function for KVM usage.

Thanks,
Jing

>
> Thanks,
>
> tglx