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Date:   Wed, 16 Nov 2022 13:23:23 -0600
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Subject: Re: [PATCH Part2 v6 14/49] crypto: ccp: Handle the legacy TMR
 allocation when SNP is enabled
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To:     Borislav Petkov <bp@alien8.de>
Cc:     Vlastimil Babka <vbabka@suse.cz>, x86@kernel.org,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        linux-coco@lists.linux.dev, linux-mm@kvack.org,
        linux-crypto@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com,
        jroedel@suse.de, thomas.lendacky@amd.com, hpa@zytor.com,
        ardb@kernel.org, pbonzini@redhat.com, seanjc@google.com,
        vkuznets@redhat.com, jmattson@google.com, luto@kernel.org,
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        michael.roth@amd.com, kirill@shutemov.name, ak@linux.intel.com,
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        "Kaplan, David" <David.Kaplan@amd.com>,
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From:   "Kalra, Ashish" <ashish.kalra@amd.com>
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On 11/16/2022 1:09 PM, Borislav Petkov wrote:
> On Wed, Nov 16, 2022 at 12:53:36PM -0600, Kalra, Ashish wrote:
>> Actually, these host allocated pages would have already been removed from
>> the kernel direct map,
> 
> And, as I said above, it would be a lot easier to handle any potential
> faults resulting from the host touching them by having it raise a *RMP*
> fault instead of normal *PF* fault where the latter code is a crazy mess.

Just to reiterate here, we won't be getting a *RMP* fault but will 
instead get a normal (not-present) #PF fault when the host touches these 
pages.

Sorry for any confusion about the fault signaled, earlier i mentioned we 
will get a RMP violation #PF, but actually as these pages are also 
removed from the kernel direct-map, therefore, we will get the 
not-present #PF and not the RMP #PF (core will check and signal 
not-present #PF before it performs the RMP checks).

Thanks,
Ashish