From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751705AbdKMBzV (ORCPT ); Sun, 12 Nov 2017 20:55:21 -0500 Received: from mga02.intel.com ([134.134.136.20]:24566 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751092AbdKMBzU (ORCPT ); Sun, 12 Nov 2017 20:55:20 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.44,386,1505804400"; d="scan'208";a="175045728" Date: Mon, 13 Nov 2017 18:37:59 +0800 From: Yi Zhang To: Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, rkrcmar@redhat.com, ravi.sahita@intel.com Subject: Re: [PATCH RFC 00/10] Intel EPT-Based Sub-page Write Protection Support. Message-ID: <20171113103758.GA29311@dazhang1-ssd.sh.intel.com> Mail-Followup-To: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, rkrcmar@redhat.com, ravi.sahita@intel.com References: <20171104001243.GA81548@dazhang1-ssd.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017-11-10 at 16:39:27 +0100, Paolo Bonzini wrote: > On 04/11/2017 17:54, Paolo Bonzini wrote: > > On 04/11/2017 01:12, Yi Zhang wrote: > >>> > >> Adding Ravi, > >> > >> Does anyone have further comments on current implementation, it is a > >> important feature in our next generation chip-set. > > > > What matters is not the feature, but the use case; without a use case, > > there is no point in including code for SPP in KVM. KVM doesn't use > > VMFUNC or #VE for example, because they are not necessary. > > > > SPP may become useful once we have the introspection interface. Or, if > > another hypervisor uses it, support for nested SPP may be useful (for > > example we support nested VMFUNC and should get nested #VE sooner or > > later, even though the features are not used on bare metal). > > > > Right now, however, supporting SPP does not seem to be particularly > > important honestly. > > Hi Yi Zhang, > > are you going to work on nested SPP? I guess that would be most useful > way to add SPP support to KVM (and you could also test it with > kvm-unit-tests). Hi Paolo, We Haven't planing on the nested support yet, so far there are many hardware assistance work on current SPP implemetation, and apply it in next generration icelake chip-set. Regards Yi. > > Thanks, > > Paolo