Re: [PATCH] x86/fpu: Fix irq_fpu_usable() to return false during CPU onlining
From: Ingo Molnar
Date: Mon May 19 2025 - 04:32:23 EST
> void fpu__init_cpu(void)
> {
> fpu__init_cpu_generic();
> fpu__init_cpu_xstate();
> +
> + /* Start allowing kernel-mode FPU: */
> + this_cpu_write(kernel_fpu_allowed, true);
> }
BTW., this is the chunk that fixes the crypto crash, right? If yes,
then could you please split this from the main patch, with the main
patch setting kernel_fpu_allowed very early, which should make the main
patch an identity transformation with no (expected) change in behavior.
Likewise, the cpu_disable_common change should similarly replicate the
current code, and should only be changed in the second patch.
Phasing it in like that should improve bisectability, for the off
chance of some regression.
Thanks,
Ingo