From ea156d192f5257a5bf393d33910d3b481bf8a401 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Sun, 5 Aug 2018 16:07:45 +0200 Subject: [PATCH] x86/speculation: Simplify sysfs report of VMX L1TF vulnerability 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 Signed-off-by: Thomas Gleixner --- arch/x86/kernel/cpu/bugs.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index eb4b574..b0886bd 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -762,9 +762,15 @@ 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) -- 2.7.4