Re: [PATCH 0/7] IBRS patch series

From: Linus Torvalds
Date: Thu Jan 04 2018 - 14:00:20 EST


On Thu, Jan 4, 2018 at 9:56 AM, Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx> wrote:
>
> Speculation on Skylake and later requires these patches ("dynamic IBRS")
> be used instead of retpoline[1].

Can somebody explain this part?

I was assuming that retpoline would work around this issue on all uarchs.

This seems to say "retpoline does nothing on Skylake+"

Linus