Re: [PATCH 1/2] powerpc: iommu: Bring back table group release_ownership() call

From: Jason Gunthorpe
Date: Fri Jan 26 2024 - 10:44:52 EST


On Fri, Jan 26, 2024 at 09:39:56AM -0600, Timothy Pearson wrote:
> > Just forget about the weird KVM and SPAPR stuff, leave it under the
> > kconfig of the old code and nobody will run it. Almost nobody already
> > runs it, apparently.
>
> We actually use QEMU/KVM/VFIO extensively at Raptor, so need the
> support and need it to be performant...

I wonder if you alone are the "almost" :)

The KVM entanglement was hairy and scary. I never did figure out what
was really going on there. Maybe you don't need all of it and can be
successful with a more typical iommu working model?

Suggest to tackle it after getting the first parts done.

Jason