Subject: Re: [RFC/PATCH 4/7] Powerpc MSI implementation

From: Benjamin Herrenschmidt <[email-masked]>
Date: Wed, 08 Nov 2006 14:02:45 +1100

> I'm still having a hard time wrapping my head around the sanity of not letting
> the kernel touch the hardware in the presence of a hypervisor.  How do you cope
> with hardware that follows a specification the hypervisor is not aware of?

We don't cope :-)

> This seems to be a violation of the principle that the driver knows the hardware
> better than some generic layer.

Well, we got at least the HV folks to change their interfaces so we
could explicitely tell them wether we want MSI or MSI-X ... in the
initial definition of that stuff, we couldn't (the HV did what it
wanted) and we didn't even know what it did (we still don't, but at
least we can now request specifically MSI or MSI-X).

Ben.