1 files changed, 11 insertions, 1 deletions

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index d71c8b54b696..bfca937bdcc3 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -300,6 +300,15 @@ retpoline_auto:
                 setup_force_cpu_cap(X86_FEATURE_USE_IBPB);
                 pr_info("Spectre v2 mitigation: Enabling Indirect Branch Prediction Barrier\n");
         }
+
+        /*
+         * Retpoline means the kernel is safe because it has no indirect
+         * branches. But firmware isn't, so use IBRS to protect that.
+         */
+        if (boot_cpu_has(X86_FEATURE_IBRS)) {
+                setup_force_cpu_cap(X86_FEATURE_USE_IBRS_FW);
+                pr_info("Enabling Restricted Speculation for firmware calls\n");
+        }
 }
 
 #undef pr_fmt
@@ -326,8 +335,9 @@ ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, c
         if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2))
                 return sprintf(buf, "Not affected\n");
 
-        return sprintf(buf, "%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
+        return sprintf(buf, "%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
                        boot_cpu_has(X86_FEATURE_USE_IBPB) ? ", IBPB" : "",
+                       boot_cpu_has(X86_FEATURE_USE_IBRS_FW) ? ", IBRS_FW" : "",
                        spectre_v2_module_string());
 }
 #endif