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Shutemov" Cc: Borislav Petkov , Andy Lutomirski , Sean Christopherson , Andrew Morton , Joerg Roedel , Andi Kleen , Kuppuswamy Sathyanarayanan , David Rientjes , Vlastimil Babka , Tom Lendacky , Thomas Gleixner , Peter Zijlstra , Paolo Bonzini , Ingo Molnar , Dario Faggioli , Mike Rapoport , David Hildenbrand , Mel Gorman , 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 References: <20230513220418.19357-1-kirill.shutemov@linux.intel.com> <20230513220418.19357-7-kirill.shutemov@linux.intel.com> From: Dave Hansen In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: AFCB7A0012 X-Stat-Signature: hndk176zijc5jxbmbau6hig9tre5tsh6 X-HE-Tag: 1684261652-531460 X-HE-Meta: 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 kHcanXKi E6WMi31q6/wC/BP53aSDsZbZI7RKZMwmfnIO2URVz86AI1MA9g9EkLUeLu0FMyRThvT3tFeVNLC3FnkFmlFuuGHC0EJ3cbP40Rg9PitRR+ABo8+NL6Q25lWS1SiZ4w432LNqcqUHVBQDtnTnJhIccF7C4cmUYt9jOrWexCMkpGnn8xvL41Qp2ho5bJsTHznYH76/36p3VS5sbJYsC6ju2t1c9NA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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).