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=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 9FC5DC433E1 for ; Thu, 27 Aug 2020 15:04:16 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7A20620678 for ; Thu, 27 Aug 2020 15:04:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A20620678 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kBJRQ-0007nZ-5u; Thu, 27 Aug 2020 15:03:52 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kBJRO-0007nU-PQ for xen-devel@lists.xenproject.org; Thu, 27 Aug 2020 15:03:50 +0000 X-Inumbo-ID: 218e0ac4-f14e-41c6-b541-2cd8b870ea27 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 218e0ac4-f14e-41c6-b541-2cd8b870ea27; Thu, 27 Aug 2020 15:03:49 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id DBB26B80D; Thu, 27 Aug 2020 15:04:20 +0000 (UTC) Subject: Re: [PATCH v2 2/8] x86/svm: silently drop writes to SYSCFG and related MSRs To: Roger Pau Monne Cc: xen-devel@lists.xenproject.org, Andrew Cooper , Wei Liu References: <20200820150835.27440-1-roger.pau@citrix.com> <20200820150835.27440-3-roger.pau@citrix.com> From: Jan Beulich Message-ID: <52cde027-e7c2-3ca7-3d7e-7abfe19198da@suse.com> Date: Thu, 27 Aug 2020 17:03:50 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200820150835.27440-3-roger.pau@citrix.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 20.08.2020 17:08, Roger Pau Monne wrote: > --- a/xen/arch/x86/hvm/svm/svm.c > +++ b/xen/arch/x86/hvm/svm/svm.c > @@ -1917,6 +1917,21 @@ static int svm_msr_read_intercept(unsigned int msr, uint64_t *msr_content) > goto gpf; > break; > > + case MSR_K8_TOP_MEM1: > + case MSR_K8_TOP_MEM2: > + *msr_content = 0; > + break; Any reason you don't fold this with ... > + case MSR_K8_SYSCFG: > + /* > + * Return MtrrFixDramEn: albeit the current emulated MTRR > + * implementation doesn't support the Extended Type-Field Format having > + * such bit set is common on AMD hardware and is harmless as long as > + * MtrrFixDramModEn isn't set. > + */ > + *msr_content = K8_MTRRFIXRANGE_DRAM_ENABLE; > + break; > + > case MSR_K8_VM_CR: > *msr_content = 0; > break; ... this existing case, and ... > @@ -2094,6 +2109,12 @@ static int svm_msr_write_intercept(unsigned int msr, uint64_t msr_content) > goto gpf; > break; > > + case MSR_K8_TOP_MEM1: > + case MSR_K8_TOP_MEM2: > + case MSR_K8_SYSCFG: > + /* Drop writes. */ > + break; > + > case MSR_K8_VM_CR: > /* ignore write. handle all bits as read-only. */ > break; ... similarly these? Jan