From patchwork Tue Sep 1 10:54:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Roger_Pau_Monn=C3=A9?= X-Patchwork-Id: 11747933 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B9271109B for ; Tue, 1 Sep 2020 11:12:29 +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 92B82206C0 for ; Tue, 1 Sep 2020 11:12:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=citrix.com header.i=@citrix.com header.b="hPJgy7Be" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 92B82206C0 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=citrix.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 1kD4Ba-0000ZT-3C; Tue, 01 Sep 2020 11:10:46 +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 1kD4BY-0000VB-Ec for xen-devel@lists.xenproject.org; Tue, 01 Sep 2020 11:10:44 +0000 X-Inumbo-ID: 4dc66d48-a97a-41a7-868b-b0013b3a38f6 Received: from esa2.hc3370-68.iphmx.com (unknown [216.71.145.153]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 4dc66d48-a97a-41a7-868b-b0013b3a38f6; Tue, 01 Sep 2020 11:10:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1598958643; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=E3jeYzrTbVvHtqEv2Ls5J9K9ynGLS4FHP+N0UrriWms=; b=hPJgy7BehiOddMzkN5o81O2LCoogc1yFpu1W1fpV4hsQYM54HkACJCen 5cYbSRE5GcIz/AuZWiL1jnbtqu716vzuCQo3SfDNfXQKPiMIvEXva0Qt3 luPYEeSI5b1cRt8ZKzri6W7pL4GkgV+eilkv6Sa/7BqJpS92db8aTFws9 g=; Authentication-Results: esa2.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: lLfVdKCRlzCApa0D2xmXz0BzXvmerCAvdrXWfkwG42+VYyoo5xpmZ0ov/aae8aQZQWMcb6ACXo i6OZemeN4a9vVveDN41SqvB+bSLPdC4IRSj7nZk0siFXmp3Ndhn9hnA5Cp3PqEEdrztwGxZk/S 3VcrOAcq1eHQHwoIgBngBHgEFVnLlNn5p/71CkDWWf4Tbngh+3ZdQJCAvu13llf9uef7ZHez9g 59BuieQqctgsubTiwMNOQjsIfj+vLO5sbxZUEPzNjQHha7KzcmeS5FxycrhOFSYyjLf3dNTUFs gnA= X-SBRS: 2.7 X-MesageID: 25738158 X-Ironport-Server: esa2.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.76,378,1592884800"; d="scan'208";a="25738158" From: Roger Pau Monne To: CC: Andrew Cooper , Jan Beulich , =?utf-8?q?Roger_Pau_Monn=C3=A9?= , Wei Liu , Jun Nakajima , Kevin Tian Subject: [PATCH v3 7/8] x86/hvm: Disallow access to unknown MSRs Date: Tue, 1 Sep 2020 12:54:44 +0200 Message-ID: <20200901105445.22277-8-roger.pau@citrix.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200901105445.22277-1-roger.pau@citrix.com> References: <20200901105445.22277-1-roger.pau@citrix.com> MIME-Version: 1.0 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" From: Andrew Cooper Change the catch-all behavior for MSR not explicitly handled. Instead of allow full read-access to the MSR space and silently dropping writes return an exception when the MSR is not explicitly handled. Signed-off-by: Andrew Cooper [remove rdmsr_safe from default case in svm_msr_read_intercept] Signed-off-by: Roger Pau Monné Reviewed-by: Jan Beulich Reviewed-by: Kevin Tian --- Changes since v1: - Fold chunk to remove explicit write handling of VMX MSRs just to #GP. - Remove catch-all rdmsr_safe in svm_msr_read_intercept. --- xen/arch/x86/hvm/svm/svm.c | 10 ++++------ xen/arch/x86/hvm/vmx/vmx.c | 16 ++++------------ 2 files changed, 8 insertions(+), 18 deletions(-) diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c index 0e43154c7e..66b22efdab 100644 --- a/xen/arch/x86/hvm/svm/svm.c +++ b/xen/arch/x86/hvm/svm/svm.c @@ -1964,8 +1964,7 @@ static int svm_msr_read_intercept(unsigned int msr, uint64_t *msr_content) break; default: - if ( rdmsr_safe(msr, *msr_content) == 0 ) - break; + gdprintk(XENLOG_WARNING, "RDMSR 0x%08x unimplemented\n", msr); goto gpf; } @@ -2150,10 +2149,9 @@ static int svm_msr_write_intercept(unsigned int msr, uint64_t msr_content) break; default: - /* Match up with the RDMSR side; ultimately this should go away. */ - if ( rdmsr_safe(msr, msr_content) == 0 ) - break; - + gdprintk(XENLOG_WARNING, + "WRMSR 0x%08x val 0x%016"PRIx64" unimplemented\n", + msr, msr_content); goto gpf; } diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index f6657af923..9cc9d81c41 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -3015,9 +3015,7 @@ static int vmx_msr_read_intercept(unsigned int msr, uint64_t *msr_content) break; } - if ( rdmsr_safe(msr, *msr_content) == 0 ) - break; - + gdprintk(XENLOG_WARNING, "RDMSR 0x%08x unimplemented\n", msr); goto gp_fault; } @@ -3290,11 +3288,6 @@ static int vmx_msr_write_intercept(unsigned int msr, uint64_t msr_content) __vmwrite(GUEST_IA32_DEBUGCTL, msr_content); break; - case MSR_IA32_FEATURE_CONTROL: - case MSR_IA32_VMX_BASIC ... MSR_IA32_VMX_VMFUNC: - /* None of these MSRs are writeable. */ - goto gp_fault; - case MSR_IA32_MISC_ENABLE: /* Silently drop writes that don't change the reported value. */ if ( vmx_msr_read_intercept(msr, &tmp) != X86EMUL_OKAY || @@ -3320,10 +3313,9 @@ static int vmx_msr_write_intercept(unsigned int msr, uint64_t msr_content) is_last_branch_msr(msr) ) break; - /* Match up with the RDMSR side; ultimately this should go away. */ - if ( rdmsr_safe(msr, msr_content) == 0 ) - break; - + gdprintk(XENLOG_WARNING, + "WRMSR 0x%08x val 0x%016"PRIx64" unimplemented\n", + msr, msr_content); goto gp_fault; }