On Tue, Jun 09, 2020 at 02:43:13PM -0300, Thadeu Lima de Souza Cascardo wrote:
> When SRBDS is mitigated by TSX OFF, update_srbds_msr will still read and
Are you talking about this case in srbds_select_mitigation():
if ((ia32_cap & ARCH_CAP_MDS_NO) && !boot_cpu_has(X86_FEATURE_RTM))
srbds_mitigation = SRBDS_MITIGATION_TSX_OFF;
?
and you have a system which:
* Check to see if this is one of the MDS_NO systems supporting
* TSX that are only exposed to SRBDS when TSX is enabled.
i.e., no SRBDS microcode for it and the fix is to disable TSX?
If so, I think the right fix should be to do:
if (!boot_cpu_has(X86_FEATURE_SRBDS_CTRL))
return;
in update_srbds_msr() with a comment above it explaining why that check
is being done.
Hmmm.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
