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=-5.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 0CF7CC43457 for ; Tue, 20 Oct 2020 12:18:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5A9DF222C8 for ; Tue, 20 Oct 2020 12:18:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="W+wZU3uq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5A9DF222C8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3C3D46B0068; Tue, 20 Oct 2020 08:18:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 374406B006C; Tue, 20 Oct 2020 08:18:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2632C6B006E; Tue, 20 Oct 2020 08:18:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0149.hostedemail.com [216.40.44.149]) by kanga.kvack.org (Postfix) with ESMTP id EC1646B0068 for ; Tue, 20 Oct 2020 08:18:55 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 781F21EE6 for ; Tue, 20 Oct 2020 12:18:55 +0000 (UTC) X-FDA: 77392207830.29.voice09_3e0087e2723f Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin29.hostedemail.com (Postfix) with ESMTP id 43428180868CE for ; Tue, 20 Oct 2020 12:18:55 +0000 (UTC) X-HE-Tag: voice09_3e0087e2723f X-Filterd-Recvd-Size: 3766 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by imf47.hostedemail.com (Postfix) with ESMTP for ; Tue, 20 Oct 2020 12:18:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603196334; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pRFnW5gWRuNF8oIJWmD5GYqoHTlkBEqfo58HkD0f8TY=; b=W+wZU3uqsZjbO3V+Tg5z1dVevAvzbTE0HiWu+RH4HGSf1QwfTASbse8iGyEFZ9I5AkTeOJ oNVBZRKcd92r+4nWHPjq24Xp/xWCsG+FNv3gl1Uu2WFrkqxmgk9yBjX8x9SExmOoVmSPd7 kwoaBOwoVVbw6vxp+M89vn7no0pbj2c= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-271-2PWSTa4ePPS2qoetoKllmg-1; Tue, 20 Oct 2020 08:18:52 -0400 X-MC-Unique: 2PWSTa4ePPS2qoetoKllmg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 74C3F8049DB; Tue, 20 Oct 2020 12:18:49 +0000 (UTC) Received: from [10.36.114.141] (ovpn-114-141.ams2.redhat.com [10.36.114.141]) by smtp.corp.redhat.com (Postfix) with ESMTP id A3C896EF44; Tue, 20 Oct 2020 12:18:43 +0000 (UTC) Subject: Re: [RFCv2 15/16] KVM: Unmap protected pages from direct mapping To: "Kirill A. Shutemov" , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Mike Rapoport Cc: David Rientjes , Andrea Arcangeli , Kees Cook , Will Drewry , "Edgecombe, Rick P" , "Kleen, Andi" , Liran Alon , Mike Rapoport , x86@kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" References: <20201020061859.18385-1-kirill.shutemov@linux.intel.com> <20201020061859.18385-16-kirill.shutemov@linux.intel.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: Date: Tue, 20 Oct 2020 14:18:42 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.1 MIME-Version: 1.0 In-Reply-To: <20201020061859.18385-16-kirill.shutemov@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 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 20.10.20 08:18, Kirill A. Shutemov wrote: > If the protected memory feature enabled, unmap guest memory from > kernel's direct mappings. Gah, ugly. I guess this also defeats compaction, swapping, ... oh gosh. As if all of the encrypted VM implementations didn't bring us enough ugliness already (SEV extensions also don't support reboots, but can at least kexec() IIRC). Something similar is done with secretmem [1]. And people don't seem to like fragmenting the direct mapping (including me). [1] https://lkml.kernel.org/r/20200924132904.1391-1-rppt@kernel.org -- Thanks, David / dhildenb