Message-ID: <d49fc5ba-b581-0051-bd82-1e7a4daae91b@amd.com>
Date:   Thu, 2 Feb 2023 13:39:14 +0530
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Subject: Re: [PATCH RFC v7 11/64] KVM: SEV: Support private pages in
 LAUNCH_UPDATE_DATA
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To:     Borislav Petkov <bp@alien8.de>, Michael Roth <michael.roth@amd.com>
Cc:     kvm@vger.kernel.org, linux-coco@lists.linux.dev,
        linux-mm@kvack.org, linux-crypto@vger.kernel.org, x86@kernel.org,
        linux-kernel@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, wanpengli@tencent.com, jmattson@google.com,
        luto@kernel.org, dave.hansen@linux.intel.com, slp@redhat.com,
        pgonda@google.com, peterz@infradead.org,
        srinivas.pandruvada@linux.intel.com, rientjes@google.com,
        dovmurik@linux.ibm.com, tobin@ibm.com, vbabka@suse.cz,
        kirill@shutemov.name, ak@linux.intel.com, tony.luck@intel.com,
        marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com,
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        ashish.kalra@amd.com, harald@profian.com
References: <20221214194056.161492-1-michael.roth@amd.com>
 <20221214194056.161492-12-michael.roth@amd.com> <Y9qt50zW+eJcz7cm@zn.tnic>
From:   "Nikunj A. Dadhania" <nikunj@amd.com>
In-Reply-To: <Y9qt50zW+eJcz7cm@zn.tnic>
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On 01/02/23 23:52, Borislav Petkov wrote:
> On Wed, Dec 14, 2022 at 01:40:03PM -0600, Michael Roth wrote:
>> From: Nikunj A Dadhania <nikunj@amd.com>
>>
>> Pre-boot guest payload needs to be encrypted and VMM has copied it
> 
> "has to have copied it over" I presume?

True, payload is being copied in patch 10/64 now.
 
>> over to the private-fd. Add support to get the pfn from the memfile fd
>> for encrypting the payload in-place.
> 
> Why is that a good thing?
> 
> I guess with UPM you're supposed to get the PFN of that encrypted guest
> payload from that memslot.
> 
> IOW, such commit messages are too laconic for my taste and you could try
> to explain more why this is happening instead of me having to
> "reverse-deduce" what you're doing from the code...
> 

I am updating the SEV related patches, will add more details in commit and send.

Regards
Nikunj