Re: [Patch v2] Make PCI extended config space (MMCONFIG) a driver opt-in

Linus Torvalds
2008-01-11T20:27:52Z

On Fri, 11 Jan 2008, Matthew Wilcox wrote:
>
> Ivan's patch doesn't start enabling MMCONFIG in more places than we
> currently do. It makes us use conf1 accesses for all accesses below
> 256 bytes. That fixes all known problems to date.

.. and I agree with that patch. But there will be people who try to access
extended space by mistake, and they'll have a hard-locked machine or
something.

> > Tell me what *other* armor plating you could have that actually works?
>
> The armour plating that already exists -- pci=nommconf.

No. It needs to be automatic, OR THE OTHER WAY AROUND.

Ie we disable the unsafe feature on purpose, and then force people who
access it to do so *consciously*.

Extended config space is different, for chissake! It's not even like it's
just a bigger normal config space where normal config accesses just
overflow into it. It really does have different rules etc.

Linus