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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57D3CC433EF for ; Tue, 12 Apr 2022 19:57:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E15E56B0072; Tue, 12 Apr 2022 15:57:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DC4646B0073; Tue, 12 Apr 2022 15:57:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C8C3D6B0074; Tue, 12 Apr 2022 15:57:28 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0143.hostedemail.com [216.40.44.143]) by kanga.kvack.org (Postfix) with ESMTP id BC27F6B0072 for ; Tue, 12 Apr 2022 15:57:28 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 8099F8248D52 for ; Tue, 12 Apr 2022 19:57:28 +0000 (UTC) X-FDA: 79349286576.25.FB44E97 Received: from mail-lj1-f177.google.com (mail-lj1-f177.google.com [209.85.208.177]) by imf06.hostedemail.com (Postfix) with ESMTP id 02C93180008 for ; Tue, 12 Apr 2022 19:57:27 +0000 (UTC) Received: by mail-lj1-f177.google.com with SMTP id r18so9778084ljp.0 for ; Tue, 12 Apr 2022 12:57:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=KPcbiORevCwEqMtvKJH++KF0drE74ilJoT8gFQ34EnA=; b=TSKs9eKW1GlEw++EEPezIbQGa8d6xcrKEr3la4XqzpfJPISA+7b9KTTEm23XMMJ1YV pcXKlpyq55urGdORKzGxmT1pTvZ/5QXhjKImBF6bFGimi25oLZDpt9M2DbzXX/bDQ+u3 9OTNzI18CY7dO2LOX4qCsPXJJ34xmRx72tFYZ9ATSXhsUXzw1klZnP3cX0EZtk+eprNZ tCkMhSq3MAlnJi4/eKNm3VReaN0l0QUhoN+OmB8jE4MWy6cl5AMOOOgXwh+tCG2JI/WG 9+gYtMY/ams5vv8fDesBL9oYXhTRQRnTpXvK1Fa0yRuSW4SuRnnTGhhsM6HBGKFzDmOM KMVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=KPcbiORevCwEqMtvKJH++KF0drE74ilJoT8gFQ34EnA=; b=AQYq9xRuD0cXzxjIWFi3IO6ov/Npmyj4+arK3wsXhWMqzJbwy2CoBwTwuKopn19bHj 78uAf/VyoA0mqQcxQ931TRfkvZYxDfiWttFJSruncdkRWhyEzXcWgTeKvWVAgP5qqF6B Q7sHOJpNLzSoWAOEt508BoqCLWA0OEzGQEubh/PpF0tGsI5KP9occGoxkPOVsasSxWyR cRmQXL375MZyquJfp2Cper0UMDGT7SFtGllqKzqwb4zCmc15b98XvXp0VNxAJ6hLHVla BJmS4fc9TAhxfvZiEK+YwxzKPGWuxE5bW18BW6njMVIX6lm5bluBSdK1A2FI0bYlvR1F wagA== X-Gm-Message-State: AOAM532Tj3HfUdkBAAW0tli0IBrFlqrAXG32K6yQjtPKtdKuQhUcWsu2 Xla6V4wb5NhofVGAqNctIOX8dA== X-Google-Smtp-Source: ABdhPJzmo2kVaO0teoqOt46A1/R+kt5G8p3jezRBHquWD+rDhCqurcBAW6KPrG7h2kWuiHcT+suCXg== X-Received: by 2002:a2e:a795:0:b0:24c:7f68:b382 with SMTP id c21-20020a2ea795000000b0024c7f68b382mr1118017ljf.494.1649793446359; Tue, 12 Apr 2022 12:57:26 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id g4-20020ac24d84000000b00464f178c0bbsm1843697lfe.96.2022.04.12.12.57.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Apr 2022 12:57:25 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id 446751030D2; Tue, 12 Apr 2022 22:58:59 +0300 (+03) Date: Tue, 12 Apr 2022 22:58:59 +0300 From: "Kirill A. Shutemov" To: Andy Lutomirski Cc: Chao Peng , Wanpeng Li , jun.nakajima@intel.com, kvm@vger.kernel.org, david@redhat.com, qemu-devel@nongnu.org, "J . Bruce Fields" , linux-mm@kvack.org, "H . Peter Anvin" , ak@linux.intel.com, Jonathan Corbet , Joerg Roedel , x86@kernel.org, Hugh Dickins , Steven Price , Ingo Molnar , "Maciej S . Szmigiero" , Borislav Petkov , Thomas Gleixner , Vitaly Kuznetsov , Vlastimil Babka , Jim Mattson , dave.hansen@intel.com, linux-api@vger.kernel.org, Jeff Layton , linux-kernel@vger.kernel.org, Yu Zhang , "Kirill A . Shutemov" , Sean Christopherson , linux-fsdevel@vger.kernel.org, Paolo Bonzini , Andrew Morton , Vishal Annapurve , Mike Rapoport Subject: Re: [PATCH v5 00/13] KVM: mm: fd-based approach for supporting KVM guest private memory Message-ID: <20220412195859.gjklfw3fz2lehpb5@box.shutemov.name> References: <20220310140911.50924-1-chao.p.peng@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 02C93180008 X-Stat-Signature: row4ezno3p11fzrmek8qdr84u4wru9sg X-Rspam-User: Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=shutemov-name.20210112.gappssmtp.com header.s=20210112 header.b=TSKs9eKW; dmarc=none; spf=none (imf06.hostedemail.com: domain of kirill@shutemov.name has no SPF policy when checking 209.85.208.177) smtp.mailfrom=kirill@shutemov.name X-HE-Tag: 1649793447-935301 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 Mon, Mar 28, 2022 at 01:16:48PM -0700, Andy Lutomirski wrote: > On Thu, Mar 10, 2022 at 6:09 AM Chao Peng wrote: > > > > This is the v5 of this series which tries to implement the fd-based KVM > > guest private memory. The patches are based on latest kvm/queue branch > > commit: > > > > d5089416b7fb KVM: x86: Introduce KVM_CAP_DISABLE_QUIRKS2 > > Can this series be run and a VM booted without TDX? A feature like > that might help push it forward. It would require enlightenment of the guest code. We have two options. Simple one is to limit enabling to the guest kernel, but it would require non-destructive conversion between shared->private memory. This does not seem to be compatible with current design. Other option is get memory private from time 0 of VM boot, but it requires modification of virtual BIOS to setup shared ranges as needed. I'm not sure if anybody volunteer to work on BIOS code to make it happen. Hm. -- Kirill A. Shutemov