[MODERATED] Re: [PATCH 7/9] TAA 7

On Thu, 24 Oct 2019, speck for Borislav Petkov wrote:

> "Disable TSX if the CPU is affected by the TSX Async Abort (TAA)
> vulnerability and microcode provides a special MSR - TSX_CTRL_MSR -
> which provides the required TSX control knobs. On MDS-affected parts
> where VERW takes care of the TAA vulnerability, that controlling MSR is
> not present and thus TSX cannot be disabled there."

This is true if you ignore hyperthreading.

On SMT systems, TSX disable is 100% complete mitigation, while VERW 
clearing is not.

Thanks,

-- 
Jiri Kosina
SUSE Labs