Re: [RFC PATCH v3 04/20] x86: Handle reduction in physical address size with SME

From	Borislav Petkov <bp@alien8.de>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH v3 04/20] x86: Handle reduction in physical address size with SME
Date	2016-11-15 16:40 +0100
Message-ID	<sDO02-6JS-37@gated-at.bofh.it> (permalink)
References	<sBVfj-4HF-7@gated-at.bofh.it> <sDKSt-4PB-15@gated-at.bofh.it> <sDKSt-4PB-17@gated-at.bofh.it> <sDKSt-4PB-13@gated-at.bofh.it> <sDO02-6JS-39@gated-at.bofh.it>
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On Tue, Nov 15, 2016 at 08:40:05AM -0600, Tom Lendacky wrote:
> The feature may be present and enabled even if it is not currently
> active.  In other words, the SYS_CFG MSR bit could be set but we aren't
> actually using encryption (sme_me_mask is 0).  As long as the SYS_CFG
> MSR bit is set we need to take into account the physical reduction in
> address space.

But later in the series I see sme_early_mem_enc() which tests exactly
that mask.

And in patch 12 you have:

+       /*
+        * If memory encryption is active, the trampoline area will need to
+        * be in un-encrypted memory in order to bring up other processors
+        * successfully.
+        */
+       sme_early_mem_dec(__pa(base), size);
+       sme_set_mem_unenc(base, size);

What's up?

IOW, it all sounds to me like you want to have an sme_active() helper
and use it everywhere.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

Thread

Re: [RFC PATCH v3 04/20] x86: Handle reduction in physical address  size with SME Joerg Roedel <joro@8bytes.org> - 2016-11-15 13:20 +0100
  Re: [RFC PATCH v3 04/20] x86: Handle reduction in physical address  size with SME Borislav Petkov <bp@alien8.de> - 2016-11-15 13:20 +0100
    Re: [RFC PATCH v3 04/20] x86: Handle reduction in physical address  size with SME Borislav Petkov <bp@alien8.de> - 2016-11-15 16:40 +0100
      Re: [RFC PATCH v3 04/20] x86: Handle reduction in physical address  size with SME Borislav Petkov <bp@alien8.de> - 2016-11-15 17:40 +0100
    Re: [RFC PATCH v3 04/20] x86: Handle reduction in physical address  size with SME Borislav Petkov <bp@alien8.de> - 2016-11-15 22:40 +0100

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