Re: [patch RFC 5/5] x86/speculation: Add basic speculation control code

[Andrea Arcangeli]

On Wed, Jan 10, 2018 at 12:12:53PM +0000, David Woodhouse wrote:
> IBRS is like a barrier. You must write it between the 'problematic'
> loading of the branch targets, and the kernel code which might be
> affected.
> 
> You cannot, on current hardware, merely set it once and forget about
> it. That is not sufficient.

I think you've got it all wrong...