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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 31464C32753 for ; Wed, 14 Aug 2019 14:00:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 125C4214C6 for ; Wed, 14 Aug 2019 14:00:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727687AbfHNOAe (ORCPT ); Wed, 14 Aug 2019 10:00:34 -0400 Received: from mga03.intel.com ([134.134.136.65]:6613 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726865AbfHNOAd (ORCPT ); Wed, 14 Aug 2019 10:00:33 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Aug 2019 07:00:33 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,385,1559545200"; d="scan'208";a="167434926" Received: from local-michael-cet-test.sh.intel.com (HELO localhost) ([10.239.159.128]) by orsmga007.jf.intel.com with ESMTP; 14 Aug 2019 07:00:31 -0700 Date: Wed, 14 Aug 2019 22:02:12 +0800 From: Yang Weijiang To: Paolo Bonzini Cc: Yang Weijiang , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, sean.j.christopherson@intel.com, mst@redhat.com, rkrcmar@redhat.com, jmattson@google.com, yu.c.zhang@intel.com, alazar@bitdefender.com Subject: Re: [PATCH RESEND v4 0/9] Enable Sub-page Write Protection Support Message-ID: <20190814140212.GA7625@local-michael-cet-test.sh.intel.com> References: <20190814070403.6588-1-weijiang.yang@intel.com> <5db7a1fc-994f-f95b-5813-ffe1801dbfbc@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5db7a1fc-994f-f95b-5813-ffe1801dbfbc@redhat.com> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Aug 14, 2019 at 02:36:30PM +0200, Paolo Bonzini wrote: > On 14/08/19 09:03, Yang Weijiang wrote: > > EPT-Based Sub-Page write Protection(SPP)is a HW capability which allows > > Virtual Machine Monitor(VMM) to specify write-permission for guest > > physical memory at a sub-page(128 byte) granularity. When this > > capability is enabled, the CPU enforces write-access check for sub-pages > > within a 4KB page. > > > > The feature is targeted to provide fine-grained memory protection for > > usages such as device virtualization, memory check-point and VM > > introspection etc. > > > > SPP is active when the "sub-page write protection" (bit 23) is 1 in > > Secondary VM-Execution Controls. The feature is backed with a Sub-Page > > Permission Table(SPPT), SPPT is referenced via a 64-bit control field > > called Sub-Page Permission Table Pointer (SPPTP) which contains a > > 4K-aligned physical address. > > > > Right now, only 4KB physical pages are supported for SPP. To enable SPP > > for certain physical page, we need to first make the physical page > > write-protected, then set bit 61 of the corresponding EPT leaf entry. > > While HW walks EPT, if bit 61 is set, it traverses SPPT with the guset > > physical address to find out the sub-page permissions at the leaf entry. > > If the corresponding bit is set, write to sub-page is permitted, > > otherwise, SPP induced EPT violation is generated. > > Still no testcases? > > Paolo Hi, Paolo, The testcases are included in selftest: https://lkml.org/lkml/2019/6/18/1197