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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C76B4CCA47F for ; Tue, 19 Jul 2022 22:02:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240701AbiGSWCc (ORCPT ); Tue, 19 Jul 2022 18:02:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231312AbiGSWCa (ORCPT ); Tue, 19 Jul 2022 18:02:30 -0400 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B362A5FAF5; Tue, 19 Jul 2022 15:02:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1658268149; x=1689804149; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=zqYQJv/XFExUA8Fi57QQgZNmV5/oX/XVpYLW9fg17RU=; b=EQWS2YWoP6ts0rHG8l5NnVK+EJXdxvKxe/UNMbIJuatbRZUhVdK0CgTE S1Zq+WRGs46emQtVOSvtVytu1+2UdoUyJp2uW0/B0LJC2+UZzEOvX9znI Zbfmho8bHbdDg5GUuR76MopoaOqnJHDytMwmihEDbI+rk7U98034yxZPL m22lsDBIPt50WV3ig+Oaqg1+pMOrSXb6H38EEXnUgVtoKB1kOGWSzVz/P m+l9KsLvKLIbpndHLaSupr860htr6GOFSl3KvwqMcYxDGNEjzBi/fivUR JaYCyAkZJOlFeRvjr3935HspVoCNNkeDvuIIOXsAV4VH8vs4s2pbeSvuF Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10413"; a="273454518" X-IronPort-AV: E=Sophos;i="5.92,285,1650956400"; d="scan'208";a="273454518" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2022 15:02:29 -0700 X-IronPort-AV: E=Sophos;i="5.92,285,1650956400"; d="scan'208";a="687279751" Received: from twliston-mobl1.amr.corp.intel.com (HELO [10.212.132.190]) ([10.212.132.190]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2022 15:02:27 -0700 Message-ID: <22d54786-bc12-ecc5-2b37-cbaa56090aa8@intel.com> Date: Tue, 19 Jul 2022 15:02:26 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCHv7 00/14] mm, x86/cc: Implement support for unaccepted memory Content-Language: en-US To: Borislav Petkov Cc: Ard Biesheuvel , Dionna Amalie Glaze , "Kirill A. Shutemov" , Peter Gonda , 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 , Varad Gautam , Dario Faggioli , Mike Rapoport , David Hildenbrand , Marcelo Cerri , tim.gardner@canonical.com, Khalid ElMously , philip.cox@canonical.com, the arch/x86 maintainers , Linux Memory Management List , linux-coco@lists.linux.dev, linux-efi , LKML , "Yao, Jiewen" References: <20220627223808.ihgy3epdx6ofll43@black.fi.intel.com> <20220718172159.4vwjzrfthelovcty@black.fi.intel.com> From: Dave Hansen In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/19/22 14:50, Borislav Petkov wrote: > On Tue, Jul 19, 2022 at 02:35:45PM -0700, Dave Hansen wrote: >> They're trying to design something that can (forever) handle guests that >> might not be able to accept memory. > Wait, what? > > If you can't modify those guests to teach them to accept memory, how do > you add TDX or SNP guest support to them? Mainline today, for instance, doesn't have unaccepted memory support for TDX or SEV-SNP guests. But, they both still boot fine because folks either configure it on the host side not to *have* any unaccepted memory. Or, they just live with the small (4GB??) amount of pre-accepted memory, which is fine for testing things.