Re: [PATCH] VFIO driver: Non-privileged user level PCI drivers

[Tom Lyon <pugs@lyon-about.com>]

OK, in the interest of making progress, I am about to embark on the following:

1. Create a user-iommu-domain driver - opening it will give a new empty domain.
    Ultimately this can also populate sysfs with the state of its world, which would
    also be a good addition to the base iommu stuff.
    If someone closes the fd while in use, the domain stays valid anyway until users
    drop off.

2. Add DOMAIN_SET and DOMAIN_UNSET ioctls to the vfio driver.  Require that
   a domain be set before using the VFIO_DMA_MAP_IOVA ioctl (this is the one
   that KVM wants).  However, the VFIO_DMA_MAP_ANYWHERE ioctl is the one
   which uses the dma_sg interface which has no expicit control of domains. I
   intend to keep it the way it is, but expect only non-hypervisor programs would
   want to use it.

3. Clean up the docs and other nits that folks have found.

Comments?