From: Dave Hansen <dave.hansen@intel.com>
To: Ard Biesheuvel <ardb@kernel.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: 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>, 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>,
Dario Faggioli <dfaggioli@suse.com>,
Mike Rapoport <rppt@kernel.org>,
David Hildenbrand <david@redhat.com>,
Mel Gorman <mgorman@techsingularity.net>,
marcelo.cerri@canonical.com, tim.gardner@canonical.com,
khalid.elmously@canonical.com, philip.cox@canonical.com,
aarcange@redhat.com, peterx@redhat.com, x86@kernel.org,
linux-mm@kvack.org, linux-coco@lists.linux.dev,
linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org,
Dave Hansen <dave.hansen@linux.intel.com>
Subject: Re: [PATCHv11 6/9] efi/unaccepted: Avoid load_unaligned_zeropad() stepping into unaccepted memory
Date: Tue, 16 May 2023 11:27:16 -0700 [thread overview]
Message-ID: <6fe42f66-819c-f2c8-176b-759c1c5a9cf5@intel.com> (raw)
In-Reply-To: <CAMj1kXG488uW=dpvbfvdN1fMZVJ3kCZQoW3UVQJW1F2VEXyxHg@mail.gmail.com>
On 5/16/23 11:08, Ard Biesheuvel wrote:
>> But, this approach does not work for unaccepted memory. For TDX, a load
>> from unaccepted memory will not lead to a recoverable exception within
>> the guest. The guest will exit to the VMM where the only recourse is to
>> terminate the guest.
>>
> Does this mean that the kernel maps memory before accepting it? As
> otherwise, I would assume that such an access would page fault inside
> the guest before triggering an exception related to the unaccepted
> state.
Yes, the kernel maps memory before accepting it (modulo things like
DEBUG_PAGEALLOC).
next prev parent reply other threads:[~2023-05-16 18:27 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-13 22:04 [PATCHv11 0/9] mm, x86/cc, efi: Implement support for " Kirill A. Shutemov
2023-05-13 22:04 ` [PATCHv11 1/9] mm: Add " Kirill A. Shutemov
2023-05-16 19:44 ` Tom Lendacky
2023-05-16 21:32 ` Kirill A. Shutemov
2023-05-13 22:04 ` [PATCHv11 2/9] efi/x86: Get full memory map in allocate_e820() Kirill A. Shutemov
2023-05-16 19:52 ` Tom Lendacky
2023-05-13 22:04 ` [PATCHv11 3/9] efi/libstub: Implement support for unaccepted memory Kirill A. Shutemov
2023-05-14 5:08 ` Mika Penttilä
2023-05-14 21:13 ` Kirill A. Shutemov
2023-05-16 18:01 ` Ard Biesheuvel
2023-05-16 18:06 ` Ard Biesheuvel
2023-05-13 22:04 ` [PATCHv11 4/9] x86/boot/compressed: Handle " Kirill A. Shutemov
2023-05-16 17:09 ` Liam Merwick
2023-05-17 15:52 ` Tom Lendacky
2023-05-13 22:04 ` [PATCHv11 5/9] efi: Provide helpers for " Kirill A. Shutemov
2023-05-16 12:06 ` [PATCHv11.1 5/9] efi: Add unaccepted memory support Kirill A. Shutemov
2023-05-16 17:25 ` Ard Biesheuvel
2023-05-17 15:58 ` Tom Lendacky
2023-05-13 22:04 ` [PATCHv11 6/9] efi/unaccepted: Avoid load_unaligned_zeropad() stepping into unaccepted memory Kirill A. Shutemov
2023-05-16 18:08 ` Ard Biesheuvel
2023-05-16 18:27 ` Dave Hansen [this message]
2023-05-16 18:35 ` Ard Biesheuvel
2023-05-16 19:15 ` Kirill A. Shutemov
2023-05-16 20:03 ` Dave Hansen
2023-05-16 21:52 ` Kirill A. Shutemov
2023-05-16 21:59 ` Dave Hansen
2023-05-16 22:15 ` Ard Biesheuvel
2023-05-16 18:33 ` Kirill A. Shutemov
2023-05-16 23:04 ` Dave Hansen
2023-05-17 16:07 ` Tom Lendacky
2023-05-13 22:04 ` [PATCHv11 7/9] x86/tdx: Make _tdx_hypercall() and __tdx_module_call() available in boot stub Kirill A. Shutemov
2023-05-13 22:04 ` [PATCHv11 8/9] x86/tdx: Refactor try_accept_one() Kirill A. Shutemov
2023-05-13 22:04 ` [PATCHv11 9/9] x86/tdx: Add unaccepted memory support Kirill A. Shutemov
2023-05-16 22:41 ` [PATCHv11 0/9] mm, x86/cc, efi: Implement support for unaccepted memory Tom Lendacky
2023-05-16 23:22 ` Kirill A. Shutemov
2023-05-17 14:32 ` Tom Lendacky
2023-05-17 18:36 ` Kirill A. Shutemov
2023-05-17 18:50 ` Tom Lendacky
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