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Date:   Wed, 1 Jun 2022 11:00:23 +0200
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To:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Borislav Petkov <bp@alien8.de>,
        Andy Lutomirski <luto@kernel.org>,
        Sean Christopherson <seanjc@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
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        Ard Biesheuvel <ardb@kernel.org>
Cc:     Andi Kleen <ak@linux.intel.com>,
        Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@linux.intel.com>,
        David Rientjes <rientjes@google.com>,
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References: <20220517153444.11195-1-kirill.shutemov@linux.intel.com>
 <20220517153444.11195-4-kirill.shutemov@linux.intel.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
Subject: Re: [PATCHv6 03/15] efi/x86: Get full memory map in allocate_e820()
In-Reply-To: <20220517153444.11195-4-kirill.shutemov@linux.intel.com>
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On 17.05.22 17:34, Kirill A. Shutemov wrote:
> Currently allocate_e820() only interested in the size of map and size of
> memory descriptor to determine how many e820 entries the kernel needs.
> 
> UEFI Specification version 2.9 introduces a new memory type --
> unaccepted memory. To track unaccepted memory kernel needs to allocate
> a bitmap. The size of the bitmap is dependent on the maximum physical
> address present in the system. A full memory map is required to find
> the maximum address.
> 
> Modify allocate_e820() to get a full memory map.

Usually we use max_pfn, if we want to know the maximum pfn that's
present in the system (well, IIRC, excluding hotunplug).

How exactly will this (different?) maximum from UEFI for the bitmap
interact with

max_pfn = e820__end_of_ram_pfn();

from e820 in existing code

?

-- 
Thanks,

David / dhildenb