If userspace never maps GEM object, then BO wastes hostmem space because VirtIO-GPU driver maps VRAM BO at the BO's creating time.
Make mappings on-demand by adding new RESOURCE_CREATE_BLOB IOCTL/UAPI hinting flag telling that host mapping should be deferred until first mapping is made when the flag is set by userspace. Signed-off-by: Dmitry Osipenko <[email protected]> Reviewed-by: Rob Clark <[email protected]> --- Changelog: v2: Rebased on recent kernel. Intel i915 native ctx landed to Mesa, lets to proceed with merging the mapping hint as a first user of the feature. drivers/gpu/drm/virtio/virtgpu_drv.h | 2 ++ drivers/gpu/drm/virtio/virtgpu_ioctl.c | 1 + drivers/gpu/drm/virtio/virtgpu_vram.c | 30 +++++++++++++++++++++----- include/uapi/drm/virtgpu_drm.h | 4 ++++ 4 files changed, 32 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h index f17660a71a3e..6f49213e23f8 100644 --- a/drivers/gpu/drm/virtio/virtgpu_drv.h +++ b/drivers/gpu/drm/virtio/virtgpu_drv.h @@ -84,6 +84,7 @@ struct virtio_gpu_object_params { uint32_t blob_mem; uint32_t blob_flags; uint64_t blob_id; + uint32_t blob_hints; }; struct virtio_gpu_object { @@ -507,6 +508,7 @@ struct sg_table *virtio_gpu_vram_map_dma_buf(struct virtio_gpu_object *bo, void virtio_gpu_vram_unmap_dma_buf(struct device *dev, struct sg_table *sgt, enum dma_data_direction dir); +void virtio_gpu_vram_map_deferred(struct virtio_gpu_object_vram *vram); /* virtgpu_submit.c */ int virtio_gpu_execbuffer_ioctl(struct drm_device *dev, void *data, diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c index c33c057365f8..01daa72b1310 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -489,6 +489,7 @@ static int verify_blob(struct virtio_gpu_device *vgdev, params->size = rc_blob->size; params->blob = true; params->blob_flags = rc_blob->blob_flags; + params->blob_hints = rc_blob->blob_hints; return 0; } diff --git a/drivers/gpu/drm/virtio/virtgpu_vram.c b/drivers/gpu/drm/virtio/virtgpu_vram.c index 084e80227433..4ae3cbc35dd3 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vram.c +++ b/drivers/gpu/drm/virtio/virtgpu_vram.c @@ -3,6 +3,8 @@ #include <linux/dma-mapping.h> +static DEFINE_MUTEX(map_lock); + static void virtio_gpu_vram_free(struct drm_gem_object *obj) { struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj); @@ -42,6 +44,11 @@ static int virtio_gpu_vram_mmap(struct drm_gem_object *obj, if (!(bo->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE)) return -EINVAL; + virtio_gpu_vram_map_deferred(vram); + + if (vram->map_state == STATE_INITIALIZING) + virtio_gpu_notify(vgdev); + wait_event(vgdev->resp_wq, vram->map_state != STATE_INITIALIZING); if (vram->map_state != STATE_OK) return -EINVAL; @@ -218,14 +225,27 @@ int virtio_gpu_vram_create(struct virtio_gpu_device *vgdev, virtio_gpu_cmd_resource_create_blob(vgdev, &vram->base, params, NULL, 0); - if (params->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE) { - ret = virtio_gpu_vram_map(&vram->base); - if (ret) { - virtio_gpu_vram_free(obj); - return ret; + if (!(params->blob_hints & DRM_VIRTGPU_BLOB_FLAG_HINT_DEFER_MAPPING)) { + if (params->blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE) { + ret = virtio_gpu_vram_map(&vram->base); + if (ret) { + virtio_gpu_vram_free(obj); + return ret; + } } } *bo_ptr = &vram->base; return 0; } + +void virtio_gpu_vram_map_deferred(struct virtio_gpu_object_vram *vram) +{ + if (!(vram->base.blob_flags & VIRTGPU_BLOB_FLAG_USE_MAPPABLE)) + return; + + mutex_lock(&map_lock); + if (!drm_mm_node_allocated(&vram->vram_node)) + virtio_gpu_vram_map(&vram->base); + mutex_unlock(&map_lock); +} diff --git a/include/uapi/drm/virtgpu_drm.h b/include/uapi/drm/virtgpu_drm.h index 9debb320c34b..ba09a4ee3e77 100644 --- a/include/uapi/drm/virtgpu_drm.h +++ b/include/uapi/drm/virtgpu_drm.h @@ -200,6 +200,10 @@ struct drm_virtgpu_resource_create_blob { __u32 cmd_size; __u64 cmd; __u64 blob_id; + +#define DRM_VIRTGPU_BLOB_FLAG_HINT_DEFER_MAPPING 0x0001 + __u32 blob_hints; + __u32 pad2; }; #define VIRTGPU_CONTEXT_PARAM_CAPSET_ID 0x0001 -- 2.53.0
