[PATCH 20/34] drm/amdkfd: HMM migrate vram to ram

If CPU page fault happens, HMM pgmap_ops callback migrate_to_ram start migrate memory from vram to ram in steps: 1. migrate_vma_pages get vram pages, and notify HMM to invalidate the pages, HMM interval notifier callback evict process queues 2. Allocate system memory pages 3. Use svm copy memory

[PATCH 20/34] drm/amdkfd: HMM migrate vram to ram

If CPU page fault happens, HMM pgmap_ops callback migrate_to_ram start migrate memory from vram to ram in steps: 1. migrate_vma_pages get vram pages, and notify HMM to invalidate the pages, HMM interval notifier callback evict process queues 2. Allocate system memory pages 3. Use svm copy memory