When SRBDS is mitigated by TSX OFF, update_srbds_msr will still read and write to MSR_IA32_MCU_OPT_CTRL even when that is not supported by the microcode.
Checking for X86_FEATURE_SRBDS_CTRL as a CPU feature available makes more sense than checking for SRBDS_MITIGATION_UCODE_NEEDED as the found "mitigation". Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]> Acked-by: John Johansen <[email protected]> Acked-by: Steve Beattie <[email protected]> Cc: [email protected] --- arch/x86/kernel/cpu/bugs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index b6f887be440c..ee5bdca7fd30 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -432,7 +432,7 @@ void update_srbds_msr(void) if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) return; - if (srbds_mitigation == SRBDS_MITIGATION_UCODE_NEEDED) + if (!boot_cpu_has(X86_FEATURE_SRBDS_CTRL)) return; rdmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl); -- 2.25.1
