Re: [PATCH 2/2] x86/microcode/intel: Extend BDW late-loading with platform id and LLC check

From: Borislav Petkov
Date: Mon Jan 15 2018 - 05:10:22 EST


On Mon, Jan 15, 2018 at 01:43:23PM +0800, Jia Zhang wrote:
> The commit b94b73733171
> ("x86/microcode/intel: Extend BDW late-loading with a revision check")
> reduces the impact of erratum BDF90 for Broadwell process model. Now,
> the impact can be reduced further through adding the checks for
> platform id and the size of LLC per core.
>
> This fix is useful to reduce the impact for microcode update launched
> by BIOS with a must machine reset.
>
> For more details, see erratum BDF90 in document #334165 (Intel Xeon
> Processor E7-8800/4800 v4 Product Family Specification Update) from
> September 2017.

You must be looking at something NDA or so but this:

https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/xeon-e7-v4-spec-update.pdf

doesn't have none of that

> + llc_size_per_core(c) > 2621440 &&
> + c->platform_id == 0xef &&

fun.

--
Regards/Gruss,
Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.