x86/spec_ctrl: Add sysctl knobs to enable/disable SPEC_CTRL feature

[mirror_ubuntu-artful-kernel.git] / arch / x86 / kernel / cpu / microcode / core.c

diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index c4fa4a85d4cb6f4e0cb4b34cd20467879167463d..6450aeda72fcf6d8d21ad3874c2de9774dccb047 100644 (file)
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -535,6 +535,17 @@ static ssize_t reload_store(struct device *dev,
        }
        if (!ret)
                perf_check_microcode();
+
+       if (boot_cpu_has(X86_FEATURE_SPEC_CTRL)) {
+               printk_once(KERN_INFO "FEATURE SPEC_CTRL Present\n");
+               set_ibrs_supported();
+               set_ibpb_supported();
+               if (ibrs_inuse)
+                       sysctl_ibrs_enabled = 1;
+               if (ibpb_inuse)
+                       sysctl_ibpb_enabled = 1;
+       }
+
        mutex_unlock(&microcode_mutex);
        put_online_cpus();