[patch V6 11/14] MDS basics 11
Thomas Gleixner <[email protected]>
| Newsgroups | org.kernel.lore.historical-speck |
|---|---|
| Message-ID | <[email protected]> |
Subject: [patch V6 11/14] x86/speculation/mds: Add sysfs reporting for MDS From: Thomas Gleixner <[email protected]> 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 <[email protected]> Reviewed-by: Greg Kroah-Hartman <[email protected]> Reviewed-by: Borislav Petkov <[email protected]> --- V3: Copy & Paste done right :( --- Documentation/ABI/testing/sysfs-devices-system-cpu | 1 arch/x86/kernel/cpu/bugs.c | 25 +++++++++++++++++++++ drivers/base/cpu.c | 8 ++++++ include/linux/cpu.h | 2 + 4 files changed, 36 insertions(+) --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -484,6 +484,7 @@ 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 <[email protected]> Description: Information about CPU vulnerabilities --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1170,6 +1170,22 @@ static ssize_t l1tf_show_state(char *buf } #endif +static ssize_t mds_show_state(char *buf) +{ + if (!hypervisor_is_type(X86_HYPER_NATIVE)) { + return sprintf(buf, "%s; SMT Host state unknown\n", + mds_strings[mds_mitigation]); + } + + 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) @@ -1236,6 +1252,10 @@ static ssize_t cpu_show_common(struct de if (boot_cpu_has(X86_FEATURE_L1TF_PTEINV)) return l1tf_show_state(buf); break; + + case X86_BUG_MDS: + return mds_show_state(buf); + default: break; } @@ -1267,4 +1287,9 @@ 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 @@ -546,11 +546,18 @@ 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, @@ -558,6 +565,7 @@ 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 @@ -57,6 +57,8 @@ 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); extern __printf(4, 5) struct device *cpu_device_create(struct device *parent, void *drvdata,