From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paolo Bonzini , Thomas Gleixner , David Woodhouse Subject: [PATCH 4.9 097/107] x86/speculation: Simplify sysfs report of VMX L1TF vulnerability Date: Tue, 14 Aug 2018 19:18:00 +0200 Message-Id: <20180814171526.730445461@linuxfoundation.org> In-Reply-To: <20180814171520.883143803@linuxfoundation.org> References: <20180814171520.883143803@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Bonzini 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 Signed-off-by: Thomas Gleixner Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman --- 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)