On Thu, Nov 20, 2025 at 01:21:48PM +0000, Shameer Kolothum wrote: > Introduce an optional supports_address_space() callback in PCIIOMMUOps to
"supports_address_space" sounds a bit to wide to me than its indication to supporting an IOMMU address space specifically, since the "system address space" being used in this series is a legit address space as well. With that being said, I think we are fine for now, given the API docs has clarified it. If someone shares the same concern, we can rename it later. > allow a vIOMMU implementation to reject devices that should not be attached > to it. > > Currently, get_address_space() is the first and mandatory callback into the > vIOMMU layer, which always returns an address space. For certain setups, such > as hardware accelerated vIOMMUs (e.g. ARM SMMUv3 with accel=on), attaching > emulated endpoint devices is undesirable as it may impact the behavior or > performance of VFIO passthrough devices, for example, by triggering > unnecessary invalidations on the host IOMMU. > > The new callback allows a vIOMMU to check and reject unsupported devices > early during PCI device registration. > > Cc: Michael S. Tsirkin <[email protected]> > Reviewed-by: Jonathan Cameron <[email protected]> > Reviewed-by: Eric Auger <[email protected]> > Signed-off-by: Shameer Kolothum <[email protected]> Reviewed-by: Nicolin Chen <[email protected]>
