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On Thu, Nov 13, 2014 at 09:36:18AM -0800, Dan Smith wrote:
> > That sounds like something worth exploring at least, I didn't know
> > about that kernel build option until now :-) It sounds like it ought
> > to be enough to let us test the NUMA topology handling, CPU pinning
> > and probably huge pages too.
> 
> Okay. I've been vaguely referring to this as a potential test vector,
> but only just now looked up the details. That's my bad :)
> 
> > The main gap I'd see is NUMA aware PCI device assignment since the
> > PCI <-> NUMA node mapping data comes from the BIOS and it does not
> > look like this is fakeable as is.
> 
> Yeah, although I'd expect that the data is parsed and returned by a
> library or utility that may be a hook for fakeification. However, it may
> very well be more trouble than it's worth.
> 
> I still feel like we should be able to test generic PCI in a similar way
> (passing something like a USB controller through to the guest, etc).
> However, I'm willing to believe that the intersection of PCI and NUMA is
> a higher order complication :)

Oh I forgot to mention with PCI device assignment (as well as having a
bunch of PCI devices available[1]), the key requirement is an IOMMU.
AFAIK, neither Xen or KVM provide any IOMMU emulation, so I think we're
out of luck for even basic PCI assignment testing inside VMs.

Regards,
Daniel

[1] Devices which provide function level reset or PM reset capabilities,
    as bus level reset is too painful to deal with, requiring co-assignment
    of all devices on the same bus to the same guest.
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