Re: [PATCH v3 01/11] x86/boot: enumerate documentation for the x86 hardware_subarch

From: Ingo Molnar
Date: Thu Feb 25 2016 - 03:10:53 EST



* Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:

> On Feb 24, 2016 12:33 AM, "Ingo Molnar" <mingo@xxxxxxxxxx> wrote:
> >
> > For hard coded platform quirks I'd suggest we add x86_platform.quirks flags. For
> > example the F00F hack for Xen could be done via:
> >
> > x86_platform.quirks.idt_remap = 0;
> >
>
> Don't we unconditionally remap the IDT? I think Kees did it for
> general purpose hardening due to our complete inability to hide the
> IDT address. I.e. I think we can remove the f00f condition entirely.

Yeah, indeed - I only judged by the (limited) patch context and assumed the Xen
problem was with IDT remapping.

But what the quirk really does is only to avoid printing the f00f workaround -
i.e. a cosmetic change. I think we should just drop the paravirt_enabled() check.

Thanks,

Ingo