From patchwork Thu Jan 7 20:34:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boris Ostrovsky X-Patchwork-Id: 12004837 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_GIT 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 A1B70C433E0 for ; Thu, 7 Jan 2021 20:35:32 +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 46C2E23443 for ; Thu, 7 Jan 2021 20:35:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 46C2E23443 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.63101.112035 (Exim 4.92) (envelope-from ) id 1kxc0B-0002TT-AE; Thu, 07 Jan 2021 20:35:23 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 63101.112035; Thu, 07 Jan 2021 20:35:23 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kxc0B-0002TJ-5c; Thu, 07 Jan 2021 20:35:23 +0000 Received: by outflank-mailman (input) for mailman id 63101; Thu, 07 Jan 2021 20:35:22 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kxc0A-0002Nv-H6 for xen-devel@lists.xenproject.org; Thu, 07 Jan 2021 20:35:22 +0000 Received: from aserp2130.oracle.com (unknown [141.146.126.79]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 046297dd-aae7-4367-bbc6-18123069346c; Thu, 07 Jan 2021 20:35:13 +0000 (UTC) Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 107KZ0FY043493; Thu, 7 Jan 2021 20:35:10 GMT Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2130.oracle.com with ESMTP id 35wcuxxk16-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 07 Jan 2021 20:35:10 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 107KYTNd084995; Thu, 7 Jan 2021 20:35:10 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3020.oracle.com with ESMTP id 35w3qu7dqw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 07 Jan 2021 20:35:09 +0000 Received: from abhmp0016.oracle.com (abhmp0016.oracle.com [141.146.116.22]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 107KZ8Yu030852; Thu, 7 Jan 2021 20:35:08 GMT Received: from ovs104.us.oracle.com (/10.149.224.204) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 07 Jan 2021 20:35:08 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 046297dd-aae7-4367-bbc6-18123069346c DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2020-01-29; bh=Bhn1XpcYtMjdOpy5EowmGrcJmomV82yzTHtsIJQu40A=; b=LNkPhjN/1mKq6dcW9CcPaSO7HXu8CtViKdQ9RgoO9FhFnEGnTw5eCvYCvQFCFsbnyfRs /r2JBsJleBpbknC1KwZxNnOoech2/uVnR6mGHBMmSFIBdHQBah+Ut6kVvLlUSm0PKJ8l wIThNXauAPWMMUbmN6SVilTI2e4dT06Sqyq/YBeMt5rKtR7yG+JJW+Mk5wC97XT+PhzB 0liLoxp78FJvIaL/Nh2kMb9yng0xeUK0N03gFDk3KxZI3Oc/iKW8I8ABt8WOcYljoHR0 BbwBUSPU5L6zGh4AN+4hFT1o1pgJjFGjiZ2N8LZLYKhWel9Dxg3rCkXL9MjEjgJbGWuA ew== From: Boris Ostrovsky To: xen-devel@lists.xenproject.org Cc: iwj@xenproject.org, wl@xen.org, anthony.perard@citrix.com, jbeulich@suse.com, andrew.cooper3@citrix.com, roger.pau@citrix.com, jun.nakajima@intel.com, kevin.tian@intel.com, boris.ostrvsky@oracle.com Subject: [PATCH 3/4] x86: Allow non-faulting accesses to non-emulated MSRs if policy permits this Date: Thu, 7 Jan 2021 15:34:57 -0500 Message-Id: <1610051698-23675-4-git-send-email-boris.ostrovsky@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1610051698-23675-1-git-send-email-boris.ostrovsky@oracle.com> References: <1610051698-23675-1-git-send-email-boris.ostrovsky@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9857 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 malwarescore=0 mlxscore=0 spamscore=0 mlxlogscore=999 phishscore=0 bulkscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101070120 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9857 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 bulkscore=0 clxscore=1015 spamscore=0 impostorscore=0 priorityscore=1501 mlxscore=0 adultscore=0 mlxlogscore=999 lowpriorityscore=0 phishscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101070120 Starting with commit 84e848fd7a16 ("x86/hvm: disallow access to unknown MSRs") accesses to unhandled MSRs result in #GP sent to the guest. This caused a regression for Solaris who tries to acccess MSR_RAPL_POWER_UNIT and (unlike, for example, Linux) does not catch exceptions when accessing MSRs that potentially may not be present. Instead of special-casing RAPL registers we decide what to do when any non-emulated MSR is accessed based on ignore_msrs field of msr_policy. Signed-off-by: Boris Ostrovsky --- xen/arch/x86/hvm/svm/svm.c | 10 ++++------ xen/arch/x86/hvm/vmx/vmx.c | 10 ++++------ xen/arch/x86/msr.c | 20 ++++++++++++++++++++ xen/arch/x86/pv/emul-priv-op.c | 8 ++++---- xen/include/asm-x86/msr.h | 3 ++- 5 files changed, 34 insertions(+), 17 deletions(-) diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c index b819897a4a9f..c9a93448f071 100644 --- a/xen/arch/x86/hvm/svm/svm.c +++ b/xen/arch/x86/hvm/svm/svm.c @@ -1965,8 +1965,8 @@ static int svm_msr_read_intercept(unsigned int msr, uint64_t *msr_content) break; default: - gdprintk(XENLOG_WARNING, "RDMSR 0x%08x unimplemented\n", msr); - goto gpf; + if ( guest_unhandled_msr(v, msr, msr_content, false) ) + goto gpf; } HVM_DBG_LOG(DBG_LEVEL_MSR, "returns: ecx=%x, msr_value=%"PRIx64, @@ -2151,10 +2151,8 @@ static int svm_msr_write_intercept(unsigned int msr, uint64_t msr_content) break; default: - gdprintk(XENLOG_WARNING, - "WRMSR 0x%08x val 0x%016"PRIx64" unimplemented\n", - msr, msr_content); - goto gpf; + if ( guest_unhandled_msr(v, msr, &msr_content, true) ) + goto gpf; } return X86EMUL_OKAY; diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index 2d4475ee3de2..34524c7a6f00 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -3017,8 +3017,8 @@ static int vmx_msr_read_intercept(unsigned int msr, uint64_t *msr_content) break; } - gdprintk(XENLOG_WARNING, "RDMSR 0x%08x unimplemented\n", msr); - goto gp_fault; + if ( guest_unhandled_msr(curr, msr, msr_content, false) ) + goto gp_fault; } done: @@ -3319,10 +3319,8 @@ static int vmx_msr_write_intercept(unsigned int msr, uint64_t msr_content) is_last_branch_msr(msr) ) break; - gdprintk(XENLOG_WARNING, - "WRMSR 0x%08x val 0x%016"PRIx64" unimplemented\n", - msr, msr_content); - goto gp_fault; + if ( guest_unhandled_msr(v, msr, &msr_content, true) ) + goto gp_fault; } return X86EMUL_OKAY; diff --git a/xen/arch/x86/msr.c b/xen/arch/x86/msr.c index be8e36386250..e624fc8694bf 100644 --- a/xen/arch/x86/msr.c +++ b/xen/arch/x86/msr.c @@ -164,6 +164,26 @@ int init_vcpu_msr_policy(struct vcpu *v) return 0; } +/* Returns true if policy requires #GP to the guest. */ +bool guest_unhandled_msr(const struct vcpu *v, uint32_t msr, + uint64_t *val, bool is_write) +{ + const struct msr_policy *mp = v->domain->arch.msr; + + if ( unlikely(mp->ignore_msrs != MSR_UNHANDLED_NEVER) && !is_write ) + *val = 0; + + if ( likely(mp->ignore_msrs != MSR_UNHANDLED_SILENT) ) { + if ( is_write ) + gdprintk(XENLOG_WARNING, "WRMSR 0x%08x val 0x%016"PRIx64 + " unimplemented\n", msr, *val); + else + gdprintk(XENLOG_WARNING, "RDMSR 0x%08x unimplemented\n", msr); + } + + return (mp->ignore_msrs == MSR_UNHANDLED_NEVER); +} + int guest_rdmsr(struct vcpu *v, uint32_t msr, uint64_t *val) { const struct vcpu *curr = current; diff --git a/xen/arch/x86/pv/emul-priv-op.c b/xen/arch/x86/pv/emul-priv-op.c index dbceed8a05fd..96d90eb30adc 100644 --- a/xen/arch/x86/pv/emul-priv-op.c +++ b/xen/arch/x86/pv/emul-priv-op.c @@ -984,7 +984,8 @@ static int read_msr(unsigned int reg, uint64_t *val, } /* fall through */ default: - gdprintk(XENLOG_WARNING, "RDMSR 0x%08x unimplemented\n", reg); + if ( !guest_unhandled_msr(curr, reg, val, false) ) + return X86EMUL_OKAY; break; normal: @@ -1146,9 +1147,8 @@ static int write_msr(unsigned int reg, uint64_t val, } /* fall through */ default: - gdprintk(XENLOG_WARNING, - "WRMSR 0x%08x val 0x%016"PRIx64" unimplemented\n", - reg, val); + if ( !guest_unhandled_msr(curr, reg, &val, true) ) + return X86EMUL_OKAY; break; invalid: diff --git a/xen/include/asm-x86/msr.h b/xen/include/asm-x86/msr.h index 16f95e734428..43a48e1a50ce 100644 --- a/xen/include/asm-x86/msr.h +++ b/xen/include/asm-x86/msr.h @@ -345,5 +345,6 @@ int init_vcpu_msr_policy(struct vcpu *v); */ int guest_rdmsr(struct vcpu *v, uint32_t msr, uint64_t *val); int guest_wrmsr(struct vcpu *v, uint32_t msr, uint64_t val); - +bool guest_unhandled_msr(const struct vcpu *v, uint32_t msr, + uint64_t *val, bool is_write); #endif /* __ASM_MSR_H */