From: David Hildenbrand <david@redhat.com>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: "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>,
Joerg Roedel <jroedel@suse.de>, Ard Biesheuvel <ardb@kernel.org>,
Andi Kleen <ak@linux.intel.com>,
Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>,
David Rientjes <rientjes@google.com>,
Vlastimil Babka <vbabka@suse.cz>,
Tom Lendacky <thomas.lendacky@amd.com>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Ingo Molnar <mingo@redhat.com>,
Varad Gautam <varad.gautam@suse.com>,
Dario Faggioli <dfaggioli@suse.com>,
Dave Hansen <dave.hansen@intel.com>,
Mike Rapoport <rppt@kernel.org>,
marcelo.cerri@canonical.com, tim.gardner@canonical.com,
khalid.elmously@canonical.com, philip.cox@canonical.com,
x86@kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev,
linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCHv6 03/15] efi/x86: Get full memory map in allocate_e820()
Date: Wed, 1 Jun 2022 16:39:16 +0200 [thread overview]
Message-ID: <116f7be4-7b75-a83b-899b-c23b52534b30@redhat.com> (raw)
In-Reply-To: <20220601143515.iavmtysdchirbtel@box.shutemov.name>
On 01.06.22 16:35, Kirill A. Shutemov wrote:
> On Wed, Jun 01, 2022 at 11:00:23AM +0200, David Hildenbrand wrote:
>> 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
>>
>> ?
>
> I'm not sure I understand the question.
Essentially, if the PFN you calculate here for the bitmap size will
essentially match later max_pfn.
>
> On EFI system, E820 is constructed based on EFI memory map and size of
> bitmap calculated based of EFI memmap will always be enough to address all
> memory. e820__end_of_ram_pfn() can be smaller than what what we calculate
> as size of memory here, if kernel reserve very top of the memory, but it
> will never be larger.
>
> Later during the boot we use e820__end_of_ram_pfn() to infer size of
> bitmap and it is safe.
>
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2022-06-01 14:39 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-17 15:34 [PATCHv6 00/15] mm, x86/cc: Implement support for unaccepted memory Kirill A. Shutemov
2022-05-17 15:34 ` [PATCHv6 01/15] x86/boot: Centralize __pa()/__va() definitions Kirill A. Shutemov
2022-05-17 15:34 ` [PATCHv6 02/15] mm: Add support for unaccepted memory Kirill A. Shutemov
2022-05-17 17:45 ` Andrew Morton
2022-05-17 18:04 ` Kirill A. Shutemov
2022-05-19 10:43 ` Gupta, Pankaj
2022-05-19 11:55 ` Kirill A. Shutemov
2022-05-19 14:33 ` Gupta, Pankaj
2022-06-01 8:47 ` David Hildenbrand
2022-05-17 15:34 ` [PATCHv6 03/15] efi/x86: Get full memory map in allocate_e820() Kirill A. Shutemov
2022-06-01 9:00 ` David Hildenbrand
2022-06-01 14:35 ` Kirill A. Shutemov
2022-06-01 14:39 ` David Hildenbrand [this message]
2022-06-01 14:46 ` Kirill A. Shutemov
2022-05-17 15:34 ` [PATCHv6 04/15] x86/boot: Add infrastructure required for unaccepted memory support Kirill A. Shutemov
2022-05-17 15:34 ` [PATCHv6 05/15] efi/x86: Implement support for unaccepted memory Kirill A. Shutemov
2022-05-17 15:34 ` [PATCHv6 06/15] x86/boot/compressed: Handle " Kirill A. Shutemov
2022-05-17 15:34 ` [PATCHv6 07/15] x86/mm: Reserve unaccepted memory bitmap Kirill A. Shutemov
2022-05-17 15:34 ` [PATCHv6 08/15] x86/mm: Provide helpers for unaccepted memory Kirill A. Shutemov
2022-05-17 15:34 ` [PATCHv6 09/15] x86/mm: Avoid load_unaligned_zeropad() stepping into " Kirill A. Shutemov
2022-05-17 15:34 ` [PATCHv6 10/15] x86/mm: Report unaccepted memory in /proc/meminfo Kirill A. Shutemov
2022-06-02 8:39 ` David Hildenbrand
2022-05-17 15:34 ` [PATCHv6 11/15] x86: Disable kexec if system has unaccepted memory Kirill A. Shutemov
2022-05-17 15:34 ` [PATCHv6 12/15] x86/tdx: Make _tdx_hypercall() and __tdx_module_call() available in boot stub Kirill A. Shutemov
2022-05-17 15:34 ` [PATCHv6 13/15] x86/tdx: Refactor try_accept_one() Kirill A. Shutemov
2022-05-17 15:34 ` [PATCHv6 14/15] x86/tdx: Add unaccepted memory support Kirill A. Shutemov
2022-05-17 15:34 ` [PATCHv6 15/15] mm/vmstat: Add counter for memory accepting Kirill A. Shutemov
2022-06-01 9:05 ` David Hildenbrand
2022-06-01 14:41 ` Kirill A. Shutemov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=116f7be4-7b75-a83b-899b-c23b52534b30@redhat.com \
--to=david@redhat.com \
--cc=ak@linux.intel.com \
--cc=akpm@linux-foundation.org \
--cc=ardb@kernel.org \
--cc=bp@alien8.de \
--cc=dave.hansen@intel.com \
--cc=dfaggioli@suse.com \
--cc=jroedel@suse.de \
--cc=khalid.elmously@canonical.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=kirill@shutemov.name \
--cc=linux-coco@lists.linux.dev \
--cc=linux-efi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=marcelo.cerri@canonical.com \
--cc=mingo@redhat.com \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=philip.cox@canonical.com \
--cc=rientjes@google.com \
--cc=rppt@kernel.org \
--cc=sathyanarayanan.kuppuswamy@linux.intel.com \
--cc=seanjc@google.com \
--cc=tglx@linutronix.de \
--cc=thomas.lendacky@amd.com \
--cc=tim.gardner@canonical.com \
--cc=varad.gautam@suse.com \
--cc=vbabka@suse.cz \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).