On 12/11/2018 03:19 PM, Borislav Petkov wrote: > On Tue, Dec 11, 2018 at 07:19:09PM +0000, Lendacky, Thomas wrote: >> Alternatively, I can reuse SPECTRE_V2_USER_STRICT and issue pr_info_once() >> to show that the method has been switched. This would reduce the changes >> to the code, but then the sysfs information doesn't show the switch (which >> may be just fine). > > You can still query X86_FEATURE_AMD_STIBP_ALWAYS_ON in stibp_state(), > no?
If using just SPECTRE_V2_USER_STRICT then the code in stibp_state() would have to be able differentiate between the case where the mode was switched because of X86_FEATURE_AMD_STIBP_ALWAYS_ON vs a kernel command line with "spectre_v2_user=on". I could always set and use a static variable in the file just for the stibp_state() case. > > But yeah, forcing SPECTRE_V2_USER_STRICT on STIBP_ALWAYS_ON makes sense > to me, with the already gazillion options we have :-\ I'll give it a bit of time and see if there's any other discussion and re-submit without the new SPECTRE_V2_USER_STRICT_PREFERRED value. Thanks, Tom >
