linux-kernel - Re: [RESEND PATCH 1/3] x86: Adding structs to reflect cpuid fields

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Message-ID: <20140918071945.GA24842@nazgul.tnic>
Date:	Thu, 18 Sep 2014 09:19:46 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	Radim Krčmář <rkrcmar@...hat.com>
Cc:	Nadav Amit <namit@...technion.ac.il>,
	Ingo Molnar <mingo@...nel.org>,
	Paolo Bonzini <pbonzini@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...hat.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	the arch/x86 maintainers <x86@...nel.org>,
	kvm <kvm@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>
Subject: Re: [RESEND PATCH 1/3] x86: Adding structs to reflect cpuid fields

On Thu, Sep 18, 2014 at 02:29:54AM +0200, Radim Krčmář wrote:
> I think you proposed to use magic constant in place of of MASK_FAM_X, so

Huh, what?

> Second problem:  Most elements don't begin at offset 0, so the usual
> retrieval would add a shift, (repurposing max_monitor_line_size)

So what?

>  max_monitor_line_size = (cpuid & MASK_FAM_X) >> OFFSET_FAM_X;
> 
> and it's not better when we write it back after doing stuff.

Writing back CPUID on baremetal? You can't be serious.

Ok, this is getting ridiculous so I'll stop wasting time. I stand by my
initial statement - this is a bad idea.

-- 
Regards/Gruss,
    Boris.
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