diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 3f727d9f0d56..e4cd3be77663 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -278,6 +278,7 @@ What: /sys/devices/system/cpu/vulnerabilities /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 diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 396d6b4034fe..999666648672 100644 --- 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 @@ -1066,6 +1067,24 @@ static void __init l1tf_select_mitigation(void) #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) @@ -1128,6 +1147,9 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr return sprintf(buf, "Mitigation: Page Table Inversion\n"); break; + case X86_BUG_MDS: + return mds_show_state(buf); + default: break; } @@ -1159,4 +1181,9 @@ ssize_t cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *b { 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 diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 41090ef5facb..3934aaf9d157 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -530,11 +530,18 @@ ssize_t __weak cpu_show_l1tf(struct device *dev, 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, @@ -542,6 +549,7 @@ static struct attribute *cpu_root_vulnerabilities_attrs[] = { &dev_attr_spectre_v2.attr, &dev_attr_spec_store_bypass.attr, &dev_attr_l1tf.attr, + &dev_attr_mds.attr, NULL }; diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 063c73ed6d78..23bdaa88ceb9 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -50,6 +50,8 @@ extern ssize_t cpu_show_spec_store_bypass(struct device *dev, 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); extern __printf(4, 5) struct device *cpu_device_create(struct device *parent, void *drvdata,