Re: [dovetail 6.1.y-cip][PATCH 1/3] arm64: fpsimd: dovetail: Hard-disable interrupts inside fpsimd_save_and_flush_cpu_state

[Philippe Gerum <rpm@xenomai.org>]

Jan Kiszka <jan.kiszka@siemens.com> writes:

> From: Jan Kiszka <jan.kiszka@siemens.com>
>
> Not all callers of this function do that themselves.
>

Are we 100% sure that kvm_arch_vcpu_load_fp() and kvm_arch_vcpu_put_fp()
would not benefit from doing that themselves precisely, to create an
atomic section around their internal state change _and_ the fpsimd flush
op?

> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  arch/arm64/kernel/fpsimd.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
> index 83b8492984982..ba804fcdfdb3f 100644
> --- a/arch/arm64/kernel/fpsimd.c
> +++ b/arch/arm64/kernel/fpsimd.c
> @@ -1951,10 +1951,10 @@ void fpsimd_save_and_flush_cpu_state(void)
>  	if (!system_supports_fpsimd())
>  		return;
>  	WARN_ON(!hard_irqs_disabled() && preemptible());
> -	__get_cpu_fpsimd_context();
> +	get_cpu_fpsimd_context();
>  	__fpsimd_save();
>  	fpsimd_flush_cpu_state();
> -	__put_cpu_fpsimd_context();
> +	put_cpu_fpsimd_context();
>  }
>  
>  #ifdef CONFIG_KERNEL_MODE_NEON

-- 
Philippe.