4.9-stable review patch. If anyone has any objections, please let me know.
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From: Paolo Bonzini pbonzini@redhat.com
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 --- arch/x86/kernel/cpu/bugs.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
--- 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)