As a first step to moving userptr handling over to drm, replace the hmm usage in xe over to gpusvm, which already offers similar functionality. As some prep steps we also align on some of the missing pieces that were already handled in xe_hmm.
v2: - Rework the gpusvm API based on feedback. - Unify SVM and userptr vm struct so we use the same notifier lock. - Drop the mark pages as dirty patch. - Various other improvements. v3: - Further unify common handling of userptr and svm in xe. -- 2.49.0
