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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 3463AC04AAF for ; Thu, 16 May 2019 16:03:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 10A3620833 for ; Thu, 16 May 2019 16:03:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728080AbfEPQDV (ORCPT ); Thu, 16 May 2019 12:03:21 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:42624 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726829AbfEPP6o (ORCPT ); Thu, 16 May 2019 11:58:44 -0400 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hRImH-0006zx-FA; Thu, 16 May 2019 16:58:41 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hRImE-0001S4-PM; Thu, 16 May 2019 16:58:38 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Greg Kroah-Hartman" , "Jon Masters" , "Borislav Petkov" , "Thomas Gleixner" Date: Thu, 16 May 2019 16:55:33 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 71/86] x86/speculation/mds: Add sysfs reporting for MDS In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.68-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner commit 8a4b06d391b0a42a373808979b5028f5c84d9c6a upstream. Add the sysfs reporting file for MDS. It exposes the vulnerability and mitigation state similar to the existing files for the other speculative hardware vulnerabilities. Signed-off-by: Thomas Gleixner Reviewed-by: Greg Kroah-Hartman Reviewed-by: Borislav Petkov Reviewed-by: Jon Masters Tested-by: Jon Masters [bwh: Backported to 3.16: - Test x86_hyper instead of using hypervisor_is_type() - Adjust context] Signed-off-by: Ben Hutchings --- --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -231,6 +231,7 @@ What: /sys/devices/system/cpu/vulnerabi /sys/devices/system/cpu/vulnerabilities/spectre_v2 /sys/devices/system/cpu/vulnerabilities/spec_store_bypass /sys/devices/system/cpu/vulnerabilities/l1tf + /sys/devices/system/cpu/vulnerabilities/mds Date: January 2018 Contact: Linux kernel mailing list Description: Information about CPU vulnerabilities --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -1131,6 +1132,24 @@ static void __init l1tf_select_mitigatio #ifdef CONFIG_SYSFS +static ssize_t mds_show_state(char *buf) +{ +#ifdef CONFIG_HYPERVISOR_GUEST + if (x86_hyper) { + return sprintf(buf, "%s; SMT Host state unknown\n", + mds_strings[mds_mitigation]); + } +#endif + + if (boot_cpu_has(X86_BUG_MSBDS_ONLY)) { + return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation], + sched_smt_active() ? "mitigated" : "disabled"); + } + + return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation], + sched_smt_active() ? "vulnerable" : "disabled"); +} + static char *stibp_state(void) { if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED) @@ -1193,6 +1212,9 @@ static ssize_t cpu_show_common(struct de return sprintf(buf, "Mitigation: Page Table Inversion\n"); break; + case X86_BUG_MDS: + return mds_show_state(buf); + default: break; } @@ -1224,4 +1246,9 @@ ssize_t cpu_show_l1tf(struct device *dev { return cpu_show_common(dev, attr, buf, X86_BUG_L1TF); } + +ssize_t cpu_show_mds(struct device *dev, struct device_attribute *attr, char *buf) +{ + return cpu_show_common(dev, attr, buf, X86_BUG_MDS); +} #endif --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -450,11 +450,18 @@ ssize_t __weak cpu_show_l1tf(struct devi return sprintf(buf, "Not affected\n"); } +ssize_t __weak cpu_show_mds(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "Not affected\n"); +} + static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL); static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL); static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL); static DEVICE_ATTR(spec_store_bypass, 0444, cpu_show_spec_store_bypass, NULL); static DEVICE_ATTR(l1tf, 0444, cpu_show_l1tf, NULL); +static DEVICE_ATTR(mds, 0444, cpu_show_mds, NULL); static struct attribute *cpu_root_vulnerabilities_attrs[] = { &dev_attr_meltdown.attr, @@ -462,6 +469,7 @@ static struct attribute *cpu_root_vulner &dev_attr_spectre_v2.attr, &dev_attr_spec_store_bypass.attr, &dev_attr_l1tf.attr, + &dev_attr_mds.attr, NULL }; --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -49,6 +49,8 @@ extern ssize_t cpu_show_spec_store_bypas struct device_attribute *attr, char *buf); extern ssize_t cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *buf); +extern ssize_t cpu_show_mds(struct device *dev, + struct device_attribute *attr, char *buf); #ifdef CONFIG_HOTPLUG_CPU extern void unregister_cpu(struct cpu *cpu);