From: Sasha Finkelstein <fnkl.kernel@xxxxxxxxx> Those are useful to implement coherent cross-vm mmap. Signed-off-by: Sasha Finkelstein <fnkl.kernel@xxxxxxxxx> --- drivers/gpu/drm/virtio/virtgpu_vram.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_vram.c b/drivers/gpu/drm/virtio/virtgpu_vram.c index 25df81c027837c248a746e41856b5aa7e216b8d5..64e2c6dbdd678ac4c0da89fdd4c9dbf937c2c335 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vram.c +++ b/drivers/gpu/drm/virtio/virtgpu_vram.c @@ -56,12 +56,11 @@ static int virtio_gpu_vram_mmap(struct drm_gem_object *obj, else if (vram->map_info == VIRTIO_GPU_MAP_CACHE_UNCACHED) vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); - /* Partial mappings of GEM buffers don't happen much in practice. */ - if (vm_size != vram->vram_node.size) + if (vm_size > vram->vram_node.size) return -EINVAL; ret = io_remap_pfn_range(vma, vma->vm_start, - vram->vram_node.start >> PAGE_SHIFT, + (vram->vram_node.start >> PAGE_SHIFT) + vma->vm_pgoff, vm_size, vma->vm_page_prot); return ret; } --- base-commit: 643e2e259c2b25a2af0ae4c23c6e16586d9fd19c change-id: 20250109-virtgpu-gem-partial-map-335ec40656d1
