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authorThomas Gleixner <tglx@linutronix.de>2019-02-18 22:51:43 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-05-14 19:19:40 +0200
commitba08d562b066f044e2985ece32b7890f556ee5ed (patch)
tree6ad73e14da12bf7b0aefcb2bbf1ff243217f6d4c /arch
parent4e722ae3141fc6aebadc722b3b10720e2ffd866f (diff)
x86/speculation/mds: Add sysfs reporting for MDS
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 <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> [bwh: Backported to 4.9: test x86_hyper instead of using hypervisor_is_type()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/cpu/bugs.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index ec91c156b820..fe374b25f3a6 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -25,6 +25,7 @@
#include <asm/vmx.h>
#include <asm/paravirt.h>
#include <asm/alternative.h>
+#include <asm/hypervisor.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
#include <asm/intel-family.h>
@@ -1161,6 +1162,24 @@ static ssize_t l1tf_show_state(char *buf)
}
#endif
+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)
@@ -1222,6 +1241,10 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
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;
}
@@ -1253,4 +1276,9 @@ 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