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

[Sebastian Andrzej Siewior]

On 2019-07-03 00:17:17 [+0200], Thomas Gleixner wrote:
> 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?

I have something half way done.

> Thanks,
> 
> 	tglx

Sebastian