Re: [gentoo-user] Where are the AMD microcode updates for spectre?

[Corbin Bird]

On 05/22/2018 03:41 AM, Adam Carter wrote:
> On Tue, May 22, 2018 at 2:47 PM, Taiidan@×××.com
> <mailto:Taiidan@×××.com> <Taiidan@×××.com <mailto:Taiidan@×××.com>> wrote:
>
>     The fam15h microcode update adds IBPB
>
>       * Indirect Branch Prediction Barrier (IBPB)
>         * PRED_CMD MSR is available:  YES
>         * CPU indicates IBPB capability:  YES  (IBPB_SUPPORT feature bit)
>
>
> My fam15 with kernel 4.16.10 and linux-firmware-20180518 confirms IBPB
> has been added;
>
> $ grep . /sys/devices/system/cpu/vulnerabilities/*
> /sys/devices/system/cpu/vulnerabilities/meltdown:Not affected
> /sys/devices/system/cpu/vulnerabilities/spectre_v1:Mitigation: __user
> pointer sanitization
> /sys/devices/system/cpu/vulnerabilities/spectre_v2:Mitigation: Full
> AMD retpoline, IBPB
>
> FWIW i saw a bunch of spectre fixes in 4.16.9
> https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.16.9
.
I cat'd /proc/cpuinfo before and after the firmware upgrade.

The new smaller Fam15h firmware adds "ibpb" and removes "lwp".

Couldn't / Didn't really find a definition of WHAT the 'lwp'
instruction(s) does.

Is 'lwp' used for anything?

Corbin