[MODERATED] Re: [patch 4/8] MDS basics 4

On Tue, Feb 19, 2019 at 01:44:10PM +0100, speck for Thomas Gleixner wrote:
> Subject: [patch 4/8] x86/speculation/mds: Conditionaly clear CPU buffers on idle entry
> From: Thomas Gleixner <[email protected]>
> 
> Add a static key which controls the invocation of the CPU buffer clear
> mechanism on idle entry. This is independent of other MDS mitigations
> because the idle entry invocation to mitigate the potential leakage due to
> store buffer repartitioning is only necessary on SMT systems.
> 
> Add the actual invocations to the different halt/mwait variants which
> covers all usage sites. mwaitx is not patched as it's not available on
> Intel CPUs.

This doesn't handle ACPI IO port idling correctly.


-Andi