From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f200.google.com (mail-wr0-f200.google.com [209.85.128.200]) by kanga.kvack.org (Postfix) with ESMTP id 45E766B02B4 for ; Fri, 9 Jun 2017 14:54:28 -0400 (EDT) Received: by mail-wr0-f200.google.com with SMTP id v104so9728110wrb.6 for ; Fri, 09 Jun 2017 11:54:28 -0700 (PDT) Received: from SMTP.EU.CITRIX.COM (smtp.eu.citrix.com. [185.25.65.24]) by mx.google.com with ESMTPS id g25si1836197edg.140.2017.06.09.11.54.26 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 09 Jun 2017 11:54:27 -0700 (PDT) Subject: Re: [Xen-devel] [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3 References: <20170607191309.28645.15241.stgit@tlendack-t1.amdoffice.net> <20170607191453.28645.92256.stgit@tlendack-t1.amdoffice.net> <4a7376fb-abfc-8edd-42b7-38de461ac65e@amd.com> <67fe69ac-a213-8de3-db28-0e54bba95127@oracle.com> <12c7e511-996d-cf60-3a3b-0be7b41bd85b@oracle.com> <9725c503-2e33-2365-87f5-f017e1cbe9b6@amd.com> <8e8eac45-95be-f1b5-6f44-f131d275f7bc@oracle.com> From: Andrew Cooper Message-ID: <2d507507-8736-89ff-0579-c2eee4b3ac34@citrix.com> Date: Fri, 9 Jun 2017 19:54:04 +0100 MIME-Version: 1.0 In-Reply-To: <8e8eac45-95be-f1b5-6f44-f131d275f7bc@oracle.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Boris Ostrovsky , Tom Lendacky , linux-arch@vger.kernel.org, linux-efi@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, iommu@lists.linux-foundation.org Cc: Brijesh Singh , Toshimitsu Kani , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Matt Fleming , Alexander Potapenko , "H. Peter Anvin" , Larry Woodman , Jonathan Corbet , Joerg Roedel , "Michael S. Tsirkin" , Ingo Molnar , Andrey Ryabinin , Dave Young , Rik van Riel , Arnd Bergmann , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , Dmitry Vyukov , Juergen Gross , xen-devel , Paolo Bonzini On 09/06/17 19:43, Boris Ostrovsky wrote: > On 06/09/2017 02:36 PM, Tom Lendacky wrote: >>> basis, although (as far as I am aware) Xen as a whole would be able to >>> encompass itself and all of its PV guests inside one single SME >>> instance. >> Yes, that is correct. Thinking more about this, it would only be possible if all the PV guests were SME-aware and understood not to choke when it finds a frame with a high address bit set. I expect the only viable way to implement this (should we wish) is to have PV guests explicitly signal support (probably via an ELF note), after which it needs to know about the existence of SME, the meaning of the encrypted bit in PTEs, and to defer all configuration responsibility to Xen. ~Andrew -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org