2606f29162
NVKM is currently responsible for managing the allocation of a client's GPU address-space, but there's various use-cases (ie. HMM address-space mirroring) where giving a client more direct control is desirable. This commit allows for a VMM to be created where the area allocated for NVKM is limited to a client-specified window, the remainder of address- space is controlled directly by the client. Leaving a window is necessary to support various internal requirements, but also to support existing allocation interfaces as not all of the HW is capable of working with a HMM allocation. Signed-off-by: Ben Skeggs <bskeggs@redhat.com>