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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 AB3D8C3A5A2 for ; Thu, 22 Aug 2019 16:38:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8BFB0206B7 for ; Thu, 22 Aug 2019 16:38:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390135AbfHVQiz (ORCPT ); Thu, 22 Aug 2019 12:38:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55970 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390108AbfHVQiq (ORCPT ); Thu, 22 Aug 2019 12:38:46 -0400 Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 819A1C049D59 for ; Thu, 22 Aug 2019 16:38:45 +0000 (UTC) Received: by mail-wr1-f72.google.com with SMTP id k10so3435042wru.23 for ; Thu, 22 Aug 2019 09:38:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:openpgp:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=p5sLbnKK73dG+WxnSvZUshy8YsfyiA1ug3q0iFIQR/I=; b=Jvb6yEJSRCsTDs+mYGBWbpoUYTso536imep14w0Opq96xDwhwwqbNwt2QRmUi65qz7 I10z358LFTxXuMIilYKN5KYsZm2I8GZ9TS9eckM5YoAlhN6WLuPK5ay+dsaC5PtYd8K6 di7lYkKOv8uGnLO0W3PmYT43KIj4p45FyCoje29KtTWaDuwIe+4iM1leawMiDfzLv5A+ JRmKjPhFl/KKHyGma7dwcxfWy/rr+MOpqd+rFeu8EN7gvz42nGofnzZ+8AU+4xPDnfp1 x22v7enJqW+MTjGXM20T4391RrH845cQfY6BG/91TOmcRAx3PBI+UW4bC+HPTOlTyvPc JIEw== X-Gm-Message-State: APjAAAWoF6/kxyZNh+PtGVOaeHRFPtk5IJtLiprY0sWoM+C3BC/GDpzs /lUky2CLVEo7Jqi2Ogiekpgag0QjhtyBzzT1ayOOAWsvBtQILSzZKPcIO18btxxrBjksDi5HT4Q vIkt179F17eURtTjcv/1B0SWX X-Received: by 2002:adf:f287:: with SMTP id k7mr48635363wro.183.1566491924174; Thu, 22 Aug 2019 09:38:44 -0700 (PDT) X-Google-Smtp-Source: APXvYqxnHZQBEz+AELXL/+aERKQQWBN+cLv9cZ3o9ly5EUJLMLeOXkg28ajJSSLGxuDTGkPLbyHorQ== X-Received: by 2002:adf:f287:: with SMTP id k7mr48635337wro.183.1566491923863; Thu, 22 Aug 2019 09:38:43 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:21b9:ff1f:a96c:9fb3? ([2001:b07:6468:f312:21b9:ff1f:a96c:9fb3]) by smtp.gmail.com with ESMTPSA id e11sm355752wrc.4.2019.08.22.09.38.42 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 22 Aug 2019 09:38:43 -0700 (PDT) Subject: Re: [PATCH RESEND v4 7/9] KVM: VMX: Handle SPP induced vmexit and page fault To: Yang Weijiang Cc: 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 References: <20190814070403.6588-1-weijiang.yang@intel.com> <20190814070403.6588-8-weijiang.yang@intel.com> <5f6ba406-17c4-a552-2352-2ff50569aac0@redhat.com> <20190820134435.GE4828@local-michael-cet-test.sh.intel.com> <20190822131745.GA20168@local-michael-cet-test> From: Paolo Bonzini Openpgp: preference=signencrypt Message-ID: <62748fe8-0a3b-0554-452e-3bb5ebaf0466@redhat.com> Date: Thu, 22 Aug 2019 18:38:41 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190822131745.GA20168@local-michael-cet-test> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/08/19 15:17, Yang Weijiang wrote: > On Tue, Aug 20, 2019 at 09:44:35PM +0800, Yang Weijiang wrote: >> On Mon, Aug 19, 2019 at 05:04:23PM +0200, Paolo Bonzini wrote: >>> fast_page_fault should never trigger an SPP userspace exit on its own, >>> all the SPP handling should go through handle_spp. > Hi, Paolo, > According to the latest SDM(28.2.4), handle_spp only handles SPPT miss and SPPT > misconfig(exit_reason==66), subpage write access violation causes EPT violation, > so have to deal with the two cases into handlers. Ok, so this part has to remain, though you do have to save/restore PT_SPP_MASK according to the rest of the email. Paolo >>> So I think that when KVM wants to write-protect the whole page >>> (wrprot_ad_disabled_spte) it must also clear PT_SPP_MASK; for example it >>> could save it in bit 53 (PT64_SECOND_AVAIL_BITS_SHIFT + 1). If the >>> saved bit is set, fast_page_fault must then set PT_SPP_MASK instead of >>> PT_WRITABLE_MASK.