Re: [PATCH] x86/fpu: Fix nofxsr regression

[Thomas Gleixner]

On Tue, 2 Jul 2019, Andi Kleen wrote:
>  
> -     if (cmdline_find_option_bool(boot_command_line, "nofxsr")) {
> +     if (!IS_ENABLED(CONFIG_64BIT) &&
> +             cmdline_find_option_bool(boot_command_line, "nofxsr")) {
> +             fpu__xstate_clear_all_cpu_caps();
>               setup_clear_cpu_cap(X86_FEATURE_FXSR);
>               setup_clear_cpu_cap(X86_FEATURE_FXSR_OPT);
>               setup_clear_cpu_cap(X86_FEATURE_XMM);

This is a mixture of disabling features explicitely and having the
dependencies in cpuid-deps. Even 2 of the existing ones are pointless
because clear(FXSR) already clears the other two.

Why not make XSAVE depend on XMM or whatever is the right dependency?

Thanks,

        tglx