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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 900A1C4321D for ; Wed, 22 Aug 2018 15:00:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 52331214FF for ; Wed, 22 Aug 2018 15:00:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 52331214FF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729337AbeHVSZt (ORCPT ); Wed, 22 Aug 2018 14:25:49 -0400 Received: from mga11.intel.com ([192.55.52.93]:48705 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729319AbeHVSZs (ORCPT ); Wed, 22 Aug 2018 14:25:48 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Aug 2018 08:00:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,274,1531810800"; d="scan'208";a="83997798" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.132]) by orsmga001.jf.intel.com with ESMTP; 22 Aug 2018 08:00:34 -0700 Date: Wed, 22 Aug 2018 08:00:34 -0700 From: Sean Christopherson To: Borislav Petkov Cc: Brijesh Singh , Paolo Bonzini , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "Lendacky, Thomas" , Thomas Gleixner Subject: Re: SEV guest regression in 4.18 Message-ID: <20180822150033.GA14200@linux.intel.com> References: <20ad6cd5-394c-d3ae-d99c-b656d7ef8293@amd.com> <20180821083911.GF24940@nazgul.tnic> <3d46f44c-dd78-8fa9-02ac-8206676ffde9@amd.com> <20180821151938.GA31212@nazgul.tnic> <92e2b80c-0dcc-94be-8d3a-5e11e5cf2370@amd.com> <20180822081417.GB4069@nazgul.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180822081417.GB4069@nazgul.tnic> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 22, 2018 at 10:14:17AM +0200, Borislav Petkov wrote: > Dropping Pavel as it bounces. > > On Tue, Aug 21, 2018 at 11:07:38AM -0500, Brijesh Singh wrote: > > The tsc_early_init() is called before setup_arch() -> init_mem_mapping. > > Ok, I see it, thanks for explaining. > > So back to your original ideas - I'm wondering whether we should define > a chunk of memory which the hypervisor and guest can share and thus > communicate over... Something ala SEV-ES also with strictly defined > layout and put all those variables there. And then the guest can map > decrypted. What about creating a data section specifically for shared memory? The section would be PMD aligned and sized so that it could be mapped appropriately without having to fracture the page. Then define a macro to easily declare data in the new section, a la __read_mostly. > There might be something similar though, I dunno. > > Maybe Paolo has a better idea... > > -- > Regards/Gruss, > Boris. > > SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) > --