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Re: [PATCH v7 08/36] x86/mm: Add support to enable SME in early boot processing

From	Thomas Gleixner <tglx@linutronix.de>
Newsgroups	linux.kernel
Subject	Re: [PATCH v7 08/36] x86/mm: Add support to enable SME in early boot processing
Date	2017-06-21 21:00 +0200
Message-ID	<tUT18-1FF-29@gated-at.bofh.it> (permalink)
References	(1 earlier) <tUlVw-5Fd-25@gated-at.bofh.it> <tUI5I-31b-15@gated-at.bofh.it> <tUQPE-6J-29@gated-at.bofh.it> <tUQPE-6J-27@gated-at.bofh.it> <tUT18-1FF-31@gated-at.bofh.it>
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On Wed, 21 Jun 2017, Tom Lendacky wrote:
> On 6/21/2017 10:38 AM, Thomas Gleixner wrote:
> > 	/*
> > 	 * Sanitize CPU configuration and retrieve the modifier
> > 	 * for the initial pgdir entry which will be programmed
> > 	 * into CR3. Depends on enabled SME encryption, normally 0.
> > 	 */
> > 	call __startup_secondary_64
> > 
> >          addq    $(init_top_pgt - __START_KERNEL_map), %rax
> > 
> > You can hide that stuff in C-code nicely without adding any cruft to the
> > ASM code.
> > 
> 
> Moving the call to verify_cpu into the C-code might be quite a bit of
> change.  Currently, the verify_cpu code is included code and not a
> global function.

Ah. Ok. I missed that.

> I can still do the __startup_secondary_64() function and then look to
> incorporate verify_cpu into both __startup_64() and
> __startup_secondary_64() as a post-patch to this series.

Yes, just having __startup_secondary_64() for now and there the extra bits
for that encryption stuff is fine.

> At least the secondary path will have a base C routine to which
> modifications can be made in the future if needed.  How does that sound?

Sounds like a plan.

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Re: [PATCH v7 08/36] x86/mm: Add support to enable SME in early boot  processing Thomas Gleixner <tglx@linutronix.de> - 2017-06-21 09:20 +0200
  Re: [PATCH v7 08/36] x86/mm: Add support to enable SME in early boot  processing Thomas Gleixner <tglx@linutronix.de> - 2017-06-21 18:40 +0200
    Re: [PATCH v7 08/36] x86/mm: Add support to enable SME in early boot  processing Thomas Gleixner <tglx@linutronix.de> - 2017-06-21 21:00 +0200

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