On Mon, 19 Feb 2018 16:43:50 -0800
Linus Torvalds <torva...@linux-foundation.org> wrote:
> On Mon, Feb 19, 2018 at 4:13 PM, Alan Cox <gno...@lxorguk.ukuu.org.uk> wrote:
> > In theory there's nothing stopping a guest getting a 'you are about to
> > gain/lose IBRS' message or having a new 'CPU' hotplugged and the old one
> > removed.
> I'm not convinced we handle the case of hotplug CPU's with different
> CPU models correctly.
We don't. And even if we did the user space doesn't. It would be a
painful task to resolve.