x86/speculation: Simplify sysfs report of VMX L1TF vulnerability

commit ea156d192f5257a5bf393d33910d3b481bf8a401 upstream

Three changes to the content of the sysfs file:

 - If EPT is disabled, L1TF cannot be exploited even across threads on the
   same core, and SMT is irrelevant.

 - If mitigation is completely disabled, and SMT is enabled, print "vulnerable"
   instead of "vulnerable, SMT vulnerable"

 - Reorder the two parts so that the main vulnerability state comes first
   and the detail on SMT is second.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index c366fdc..9da5517 100644 (file)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -737,9 +737,15 @@ static ssize_t l1tf_show_state(char *buf)
        if (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_AUTO)
                return sprintf(buf, "%s\n", L1TF_DEFAULT_MSG);
 
-       return sprintf(buf, "%s; VMX: SMT %s, L1D %s\n", L1TF_DEFAULT_MSG,
-                      cpu_smt_control == CPU_SMT_ENABLED ? "vulnerable" : "disabled",
-                      l1tf_vmx_states[l1tf_vmx_mitigation]);
+       if (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_EPT_DISABLED ||
+           (l1tf_vmx_mitigation == VMENTER_L1D_FLUSH_NEVER &&
+            cpu_smt_control == CPU_SMT_ENABLED))
+               return sprintf(buf, "%s; VMX: %s\n", L1TF_DEFAULT_MSG,
+                              l1tf_vmx_states[l1tf_vmx_mitigation]);
+
+       return sprintf(buf, "%s; VMX: %s, SMT %s\n", L1TF_DEFAULT_MSG,
+                      l1tf_vmx_states[l1tf_vmx_mitigation],
+                      cpu_smt_control == CPU_SMT_ENABLED ? "vulnerable" : "disabled");
 }
 #else
 static ssize_t l1tf_show_state(char *buf)