On Tue, Nov 02, 2021 at 12:31:39PM +0100, Maksym Wezdecki wrote:
> From: mwezdeck <maksym.wezdecki@xxxxxxxxxxxxxxx>
>
> The idea behind the commit:
> 1. not pin the pages during resource_create ioctl
> 2. pin the pages on the first use during:
> - transfer_*_host ioctl
> - map ioctl
i.e. basically lazy pinning. Approach looks sane to me.
> 3. introduce new ioctl for pinning pages on demand
What is the use case for this ioctl?
In any case this should be a separate patch.
> + struct virtio_gpu_object_array *objs;
> + struct virtio_gpu_object *bo;
> + struct virtio_gpu_object_shmem *shmem;
> +
> + objs = virtio_gpu_array_from_handles(file, &virtio_gpu_map->handle, 1);
> + if (objs == NULL)
> + return -ENOENT;
> +
> + bo = gem_to_virtio_gpu_obj(objs->objs[0]);
> + if (bo == NULL)
> + return -ENOENT;
> +
> + shmem = to_virtio_gpu_shmem(bo);
> + if (shmem == NULL)
> + return -ENOENT;
> +
> + if (!shmem->pages) {
> + virtio_gpu_object_pin(vgdev, objs, 1);
> + }
Move this into virtio_gpu_object_pin(),
or create a helper function for it ...
> + objs = virtio_gpu_array_from_handles(file, &virtio_gpu_pin->handle, 1);
> + if (objs == NULL)
> + return -ENOENT;
> +
> + bo = gem_to_virtio_gpu_obj(objs->objs[0]);
> + if (bo == NULL)
> + return -ENOENT;
> +
> + shmem = to_virtio_gpu_shmem(bo);
> + if (shmem == NULL)
> + return -ENOENT;
> +
> + if (!shmem->pages) {
> + return virtio_gpu_object_pin(vgdev, objs, 1);
> + }
... to avoid this code duplication?
> +int virtio_gpu_object_pin(struct virtio_gpu_device *vgdev,
> + struct virtio_gpu_object_array *objs,
> + int num_gem_objects)
> +{
> + int i, ret;
> +
> + for (i = 0; i < num_gem_objects; i++) {
> + ret = virtio_gpu_object_shmem_init(vgdev, bo, &ents, &nents);
> + if (ret != 0) {
> + return -EFAULT;
> + }
> +
> + virtio_gpu_object_attach(vgdev, bo, ents, nents);
I think it is enough to do the virtio_gpu_object_attach() call lazily.
virtio_gpu_object_shmem_init() should not actually allocate pages, that
only happens when virtio_gpu_object_attach() goes ask for a scatter
list.
take care,
Gerd
