Re: [PATCH 07/14] vfio: simplify iommu group allocation for mediated devices

[Jason Gunthorpe <jgg@nvidia.com>]

On Wed, Aug 25, 2021 at 02:37:42PM +0200, Christoph Hellwig wrote:
> On Wed, Aug 25, 2021 at 09:34:54AM -0300, Jason Gunthorpe wrote:
> > On Wed, Aug 25, 2021 at 02:24:00PM +0200, Christoph Hellwig wrote:
> > > On Wed, Aug 25, 2021 at 09:21:44AM -0300, Jason Gunthorpe wrote:
> > > > This feature is about creating a device that is not connected to a HW
> > > > IO page table (at least by the VFIO iommu code) but the IO page table
> > > > is held in software and accessed by the VFIO driver through the pin
> > > > API.
> > > > 
> > > > virtual_iommu is somewhat overloaded with the idea of a vIOMMU created
> > > > by qemu and stuffed into a guest..
> > > > 
> > > > "domainless" might work but I also find it confusing that the iommu
> > > > code uses the word domain to refer to a HW IO page table :\
> > > > 
> > > > Maybe "sw io page table" ?
> > > 
> > > Or simply emulated?  At least looking at i915 there is very little
> > > direct connection to the actual hardware, and while I don't understand
> > > them fully the s390 driver look similar.  And the samples are completely
> > > faked up anyway.
> > 
> > Emulated IO page table works for me!
> 
> Hmm, that is a full sentence for the comment that needs to be added.
> Are you fine with just s/mediated/emulated/ for the symbol names or
> do you want something more specific?

I think so, in context of a group or iommu function it kind of makes
sense emulated would refer to the page table/dma process

The driver entry point can have the extra words
 vfio_register_emulated_dma_dev()

Seems to read well?

Jason