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

[ebiederm@xmission.com (Eric W. Biederman)]

Benjamin Herrenschmidt <benh@kernel.crashing.org> writes:

> My initial idea was that the msi_info structure would have a variable
> lenght, that is, would end with msi_desc[0] and would be allocated to
> the the right size, but it might suck a bit :-)

That could work.  The whole array of interrupts thing allocated on
device probe, I question a little bit.  I can just about see allocating
another interrupt if you can when a network device start getting another
flow through it.  But it is working well enough at the moment it doesn't
appear time to run out and change the drivers.

>> Hopefully I can look at this a little more this evening and see what we
>> need to do to harmonize the two msi implementations.
>
> Thanks !

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?

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

Eric