From the upstream commit [0] that this update pulls in:
> Intel SPR erratum SPR4 says that if you trip into a vmexit while
> doing FPU save/restore, your AMX register state might misbehave...
> and by misbehave, I mean save all zeroes incorrectly, leading to
> explosions if you restore it.
>
> Since we're not using AMX for anything, the simple way to avoid
> this is to just not save/restore those when we do anything, since
> we're killing preemption of any sort across our save/restores.
>
> If we ever decide to use AMX, it's not clear that we have any
> way to mitigate this, on Linux...but I am not an expert.
[0]: c65aaa8387
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
d53c5ae125