Re: [PATCH v1 2/2] acpi, x86: Remove encryption mask from ACPI page protection type

From: Ingo Molnar <mingo@kernel.org>
To: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, linux-kernel@vger.kernel.org,
	Ingo Molnar <mingo@redhat.com>, Andy Lutomirski <luto@kernel.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Dave Young <dyoung@redhat.com>,
	Brijesh Singh <brijesh.singh@amd.com>
Subject: Re: [PATCH v1 2/2] acpi, x86: Remove encryption mask from ACPI page protection type
Date: Fri, 28 Jul 2017 08:28:07 +0200	[thread overview]
Message-ID: <20170728062807.k7bzg3qgxsxlllly@gmail.com> (raw)
In-Reply-To: <5d7f9a32-89d1-e2f2-4dea-98527ac3492e@amd.com>

* Tom Lendacky <thomas.lendacky@amd.com> wrote:

> > > +	 * in memory in an encrypted state so return a protection attribute
> > > +	 * that does not have the encryption bit set.
> > >   	 */
> > > -	 return PAGE_KERNEL;
> > > +	 return sme_active() ? PAGE_KERNEL_IO : PAGE_KERNEL;
> > 
> > Why isn't there a PAGE_KERNEL_NOENC define which you can simply return
> > instead of testing?
> 
> Sounds like something I should add to pgtable_types.h (which has a
> #define for PAGE_KERNEL_EXEC_NOENC, but not PAGE_KERNEL_NOENC). I'll
> create that #define.
> 
> As for the sme_active() check I was getting ahead of myself since
> under SEV the encryption mask is needed.  I'll change it to just
> return PAGE_KERNEL_NOENC and then worry about the SEV change in
> the SEV patches.

Ok, that works for me too, as we at least don't sprinke the code with repeated 
sme_active() toggles.

Thanks,

	Ingo