Re: [PATCH v2 1/2] x86/fpu: Extend kernel_fpu_begin_mask() to initialize AMX state

From: Thomas Gleixner
Date: Wed May 08 2024 - 09:00:30 EST


On Tue, May 07 2024 at 16:53, Chang S. Bae wrote:
> diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
> index 1209c7aebb21..04cc6f14ca42 100644
> --- a/arch/x86/kernel/fpu/core.c
> +++ b/arch/x86/kernel/fpu/core.c
> @@ -440,6 +440,9 @@ void kernel_fpu_begin_mask(unsigned int kfpu_mask)
>
> if (unlikely(kfpu_mask & KFPU_387) && boot_cpu_has(X86_FEATURE_FPU))
> asm volatile ("fninit");
> +
> + if (unlikely(kfpu_mask & KFPU_AMX) && boot_cpu_has(X86_FEATURE_AMX_TILE))

cpu_feature_enabled() please

> + restore_fpregs_from_fpstate(&init_fpstate, XFEATURE_MASK_XTILE);
> }
> EXPORT_SYMBOL_GPL(kernel_fpu_begin_mask);