From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7173FC433ED for ; Wed, 7 Apr 2021 14:09:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CB1226044F for ; Wed, 7 Apr 2021 14:09:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CB1226044F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5A0106B007D; Wed, 7 Apr 2021 10:09:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 529E66B007E; Wed, 7 Apr 2021 10:09:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3A2D16B0080; Wed, 7 Apr 2021 10:09:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0047.hostedemail.com [216.40.44.47]) by kanga.kvack.org (Postfix) with ESMTP id 1A7086B007D for ; Wed, 7 Apr 2021 10:09:04 -0400 (EDT) Received: from smtpin34.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id BF40D282D for ; Wed, 7 Apr 2021 14:09:03 +0000 (UTC) X-FDA: 78005752566.34.605B88E Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by imf03.hostedemail.com (Postfix) with ESMTP id 3CBD6C0007D9 for ; Wed, 7 Apr 2021 14:08:59 +0000 (UTC) IronPort-SDR: uDzTeISHR8fFKKDSH0cnFjDPBxkXRQzjBIITFvKKTcTSCccioDCTJA5JMQWIFSFe7mv8mebZWz PzlA+jXNwzZA== X-IronPort-AV: E=McAfee;i="6000,8403,9947"; a="254651158" X-IronPort-AV: E=Sophos;i="5.82,203,1613462400"; d="scan'208";a="254651158" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Apr 2021 07:09:00 -0700 IronPort-SDR: hPxEBTTpnEm6zCPwBedLV0vjmkvgtbOhKY4mExcIZZRx2HqXB1MOx29/5/ldkfN3f6QDqEi56e +EMb5TDMGXiw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,203,1613462400"; d="scan'208";a="530217945" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.54.74.11]) by orsmga004.jf.intel.com with ESMTP; 07 Apr 2021 07:09:00 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id 42C653001E2; Wed, 7 Apr 2021 07:09:00 -0700 (PDT) From: Andi Kleen To: Christophe de Dinechin Cc: "Kirill A. Shutemov" , David Hildenbrand , Dave Hansen , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Sean Christopherson , Jim Mattson , David Rientjes , "Edgecombe\, Rick P" , "Kleen\, Andi" , "Yamahata\, Isaku" , x86@kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: Re: [RFCv1 7/7] KVM: unmap guest memory using poisoned pages In-Reply-To: (Christophe de Dinechin's message of "Wed, 7 Apr 2021 15:31:28 +0200") References: <20210402152645.26680-1-kirill.shutemov@linux.intel.com> <20210402152645.26680-8-kirill.shutemov@linux.intel.com> <52518f09-7350-ebe9-7ddb-29095cd3a4d9@intel.com> <20210407131647.djajbwhqsmlafsyo@box.shutemov.name> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) Date: Wed, 07 Apr 2021 07:09:00 -0700 Message-ID: <87zgyauqyr.fsf@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain X-Rspamd-Queue-Id: 3CBD6C0007D9 X-Stat-Signature: nn98peppzt56t8633srpa17e9fd7g37c X-Rspamd-Server: rspam02 Received-SPF: none (linux.intel.com>: No applicable sender policy available) receiver=imf03; identity=mailfrom; envelope-from=""; helo=mga06.intel.com; client-ip=134.134.136.31 X-HE-DKIM-Result: none/none X-HE-Tag: 1617804539-129168 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: Christophe de Dinechin writes: > Is there even a theoretical way to restore an encrypted page e.g. from (host) > swap without breaking the integrity check? Or will that only be possible with > assistance from within the encrypted enclave? Only the later. You would need balloning. It's in principle possible, but currently not implemented. In general host swap without balloning is usually a bad idea anyways because it often just swaps a lot of cache data that could easily be thrown away instead. -andi