From: Dave Hansen <dave.hansen@intel.com>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Tom Lendacky <thomas.lendacky@amd.com>,
linux-kernel@vger.kernel.org, x86@kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Michael Roth <michael.roth@amd.com>,
Joerg Roedel <jroedel@suse.de>,
Dionna Glaze <dionnaglaze@google.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ard Biescheuvel <ardb@kernel.org>,
"Min M. Xu" <min.m.xu@intel.com>,
Gerd Hoffmann <kraxel@redhat.com>,
James Bottomley <jejb@linux.ibm.com>,
Jiewen Yao <jiewen.yao@intel.com>,
Erdem Aktas <erdemaktas@google.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: Re: [PATCH v7 6/6] x86/efi: Safely enable unaccepted memory in UEFI
Date: Tue, 4 Apr 2023 12:27:43 -0700 [thread overview]
Message-ID: <d3d95889-67ec-576e-ec9c-b9bd462e1c0e@intel.com> (raw)
In-Reply-To: <20230404180917.4fsgkzcdhqvph6io@box.shutemov.name>
On 4/4/23 11:09, Kirill A. Shutemov wrote:
>> If our AMD friends don't do this, what is their alternative?
> The alternative is coordination on the host side: VMM can load a BIOS that
> pre-accepts all memory if the kernel is older.
>
> I know that it is not convenient for VMM, but it is technically possible.
Yeah, either a specific BIOS or a knob to tell the BIOS what it has to
do. But, either way, that requires coordination between the BIOS (or
BIOS configuration) and the specific guest. I can see why that's
unpalatable.
> Introduce an ABI with an expiration date is much more ugly. And nobody
> will care about the expiration date, until you will try to remove it.
Yeah, the only real expiration date for an ABI is "never". I don't
believe for a second that we'll ever be able to remove the interface.
Either way, I'd love to hear more from folks about why a BIOS-side
option (configuration or otherwise) is not a good option. I know we've
discussed this in a few mail threads, but it would be even better to get
it into the cover letter or documentation.
next prev parent reply other threads:[~2023-04-04 19:28 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-30 11:49 [PATCHv9 00/14] mm, x86/cc: Implement support for unaccepted memory Kirill A. Shutemov
2023-03-30 11:49 ` [PATCHv9 01/14] x86/boot: Centralize __pa()/__va() definitions Kirill A. Shutemov
2023-03-30 11:49 ` [PATCHv9 02/14] mm: Add support for unaccepted memory Kirill A. Shutemov
2023-04-03 9:26 ` Vlastimil Babka
2023-04-03 10:02 ` Kirill A. Shutemov
2023-04-03 13:07 ` Vlastimil Babka
2023-03-30 11:49 ` [PATCHv9 03/14] mm/page_alloc: Fake " Kirill A. Shutemov
2023-04-03 13:39 ` Vlastimil Babka
2023-04-03 14:39 ` Kirill A. Shutemov
2023-04-03 15:50 ` Kirill A. Shutemov
2023-04-14 10:19 ` Kirill A. Shutemov
2023-04-03 14:43 ` David Hildenbrand
2023-04-03 14:47 ` Kirill A. Shutemov
2023-03-30 11:49 ` [PATCHv9 04/14] mm/page_alloc: Add sysfs handle to accept accept_memory Kirill A. Shutemov
2023-04-03 13:43 ` Vlastimil Babka
2023-04-03 14:41 ` Kirill A. Shutemov
2023-03-30 11:49 ` [PATCHv9 05/14] efi/x86: Get full memory map in allocate_e820() Kirill A. Shutemov
2023-03-30 11:49 ` [PATCHv9 06/14] x86/boot: Add infrastructure required for unaccepted memory support Kirill A. Shutemov
2023-03-30 11:49 ` [PATCHv9 07/14] efi/x86: Implement support for unaccepted memory Kirill A. Shutemov
2023-03-30 11:49 ` [PATCHv9 08/14] x86/boot/compressed: Handle " Kirill A. Shutemov
2023-03-30 11:49 ` [PATCHv9 09/14] x86/mm: Reserve unaccepted memory bitmap Kirill A. Shutemov
2023-03-30 11:49 ` [PATCHv9 10/14] x86/mm: Provide helpers for unaccepted memory Kirill A. Shutemov
2023-03-30 11:49 ` [PATCHv9 11/14] x86/mm: Avoid load_unaligned_zeropad() stepping into " Kirill A. Shutemov
2023-04-03 13:28 ` Vlastimil Babka
2023-04-03 14:42 ` Kirill A. Shutemov
2023-03-30 11:49 ` [PATCHv9 12/14] x86/tdx: Make _tdx_hypercall() and __tdx_module_call() available in boot stub Kirill A. Shutemov
2023-03-30 11:49 ` [PATCHv9 13/14] x86/tdx: Refactor try_accept_one() Kirill A. Shutemov
2023-03-30 11:49 ` [PATCHv9 14/14] x86/tdx: Add unaccepted memory support Kirill A. Shutemov
2023-04-03 14:42 ` [PATCHv9 00/14] mm, x86/cc: Implement support for unaccepted memory Vlastimil Babka
2023-04-16 19:19 ` Kirill A. Shutemov
2023-04-17 7:37 ` Vlastimil Babka
2023-04-04 17:23 ` [PATCH v7 0/6] Provide SEV-SNP " Tom Lendacky
2023-04-04 17:23 ` [PATCH v7 1/6] x86/sev: Fix calculation of end address based on number of pages Tom Lendacky
2023-04-04 17:23 ` [PATCH v7 2/6] x86/sev: Put PSC struct on the stack in prep for unaccepted memory support Tom Lendacky
2023-04-04 17:23 ` [PATCH v7 3/6] x86/sev: Allow for use of the early boot GHCB for PSC requests Tom Lendacky
2023-04-04 17:23 ` [PATCH v7 4/6] x86/sev: Use large PSC requests if applicable Tom Lendacky
2023-04-04 17:23 ` [PATCH v7 5/6] x86/sev: Add SNP-specific unaccepted memory support Tom Lendacky
2023-04-04 17:23 ` [PATCH v7 6/6] x86/efi: Safely enable unaccepted memory in UEFI Tom Lendacky
2023-04-04 17:45 ` Kirill A. Shutemov
2023-04-04 17:57 ` Dave Hansen
2023-04-04 18:09 ` Kirill A. Shutemov
2023-04-04 19:27 ` Dave Hansen [this message]
2023-04-04 19:49 ` Ard Biesheuvel
2023-04-04 20:24 ` Kirill A. Shutemov
2023-04-04 20:41 ` Ard Biesheuvel
2023-04-04 21:01 ` Kirill A. Shutemov
2023-04-05 7:46 ` Ard Biesheuvel
2023-04-05 13:00 ` Dave Hansen
2023-04-05 13:44 ` Ard Biesheuvel
2023-04-05 16:15 ` Dave Hansen
2023-04-05 19:06 ` Kirill A. Shutemov
2023-04-05 20:11 ` Tom Lendacky
2023-04-05 21:22 ` Dave Hansen
2023-04-05 21:34 ` Ard Biesheuvel
2023-04-05 13:42 ` Kirill A. Shutemov
2023-04-05 13:51 ` Ard Biesheuvel
2023-04-05 10:06 ` Gerd Hoffmann
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