[PATCH] drm/virtio: delay pinning the pages till first use

2 Nov 2021

From: mwezdeck maksym.wezdecki@collabora.co.uk
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
  3. introduce new ioctl for pinning pages on demand
This change has no impact on user space.
Signed-off-by: mwezdeck maksym.wezdecki@collabora.co.uk
---
 drivers/gpu/drm/virtio/virtgpu_drv.h    |  6 ++-
 drivers/gpu/drm/virtio/virtgpu_ioctl.c  | 65 +++++++++++++++++++++++++
 drivers/gpu/drm/virtio/virtgpu_object.c | 42 ++++++++++++----
 include/uapi/drm/virtgpu_drm.h          | 10 ++++
 4 files changed, 113 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index e0265fe74aa5..cf2cad663575 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -278,7 +278,7 @@ struct virtio_gpu_fpriv {
 };
/* virtgpu_ioctl.c */
-#define DRM_VIRTIO_NUM_IOCTLS 12
+#define DRM_VIRTIO_NUM_IOCTLS 13
 extern struct drm_ioctl_desc virtio_gpu_ioctls[DRM_VIRTIO_NUM_IOCTLS];
 void virtio_gpu_create_context(struct drm_device *dev, struct drm_file *file);
@@ -455,6 +455,10 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
    		     struct virtio_gpu_object **bo_ptr,
    		     struct virtio_gpu_fence *fence);
+int virtio_gpu_object_pin(struct virtio_gpu_device *vgdev,
+			  struct virtio_gpu_object_array *objs,
+			  int num_gem_objects);
+
 bool virtio_gpu_is_shmem(struct virtio_gpu_object *bo);
int virtio_gpu_resource_id_get(struct virtio_gpu_device *vgdev,
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 5618a1d5879c..49bf53f358b5 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -102,6 +102,25 @@ static int virtio_gpu_map_ioctl(struct drm_device *dev, void *data,
 {
    struct virtio_gpu_device *vgdev = dev->dev_private;
    struct drm_virtgpu_map *virtio_gpu_map = data;
+	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);
+	}
return virtio_gpu_mode_dumb_mmap(file, vgdev->ddev,
    				 virtio_gpu_map->handle,
@@ -292,6 +311,9 @@ static int virtio_gpu_getparam_ioctl(struct drm_device *dev, void *data,
    case VIRTGPU_PARAM_SUPPORTED_CAPSET_IDs:
    	value = vgdev->capset_id_mask;
    	break;
+	case VIRTGPU_PARAM_PIN_ON_DEMAND:
+		value = 1;
+		break;
    default:
    	return -EINVAL;
    }
@@ -397,6 +419,7 @@ static int virtio_gpu_transfer_from_host_ioctl(struct drm_device *dev,
    struct virtio_gpu_object *bo;
    struct virtio_gpu_object_array *objs;
    struct virtio_gpu_fence *fence;
+	struct virtio_gpu_object_shmem *shmem;
    int ret;
    u32 offset = args->offset;
@@ -414,6 +437,11 @@ static int virtio_gpu_transfer_from_host_ioctl(struct drm_device *dev,
    	goto err_put_free;
    }
+	shmem = to_virtio_gpu_shmem(bo);
+	if (!shmem->pages) {
+		virtio_gpu_object_pin(vgdev, objs, 1);
+	}
+
    if (!bo->host3d_blob && (args->stride || args->layer_stride)) {
    	ret = -EINVAL;
    	goto err_put_free;
@@ -451,6 +479,7 @@ static int virtio_gpu_transfer_to_host_ioctl(struct drm_device *dev, void *data,
    struct drm_virtgpu_3d_transfer_to_host *args = data;
    struct virtio_gpu_object *bo;
    struct virtio_gpu_object_array *objs;
+	struct virtio_gpu_object_shmem *shmem;
    struct virtio_gpu_fence *fence;
    int ret;
    u32 offset = args->offset;
@@ -465,6 +494,11 @@ static int virtio_gpu_transfer_to_host_ioctl(struct drm_device *dev, void *data,
    	goto err_put_free;
    }
+	shmem = to_virtio_gpu_shmem(bo);
+	if (!shmem->pages) {
+		virtio_gpu_object_pin(vgdev, objs, 1);
+	}
+
    if (!vgdev->has_virgl_3d) {
    	virtio_gpu_cmd_transfer_to_host_2d
    		(vgdev, offset,
@@ -836,6 +870,34 @@ static int virtio_gpu_context_init_ioctl(struct drm_device *dev,
    return ret;
 }
+static int virtio_gpu_pin_ioctl(struct drm_device *dev, void *data,
+				struct drm_file *file)
+{
+	struct virtio_gpu_device *vgdev = dev->dev_private;
+	struct drm_virtgpu_pin *virtio_gpu_pin = data;
+	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_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);
+	}
+
+	return 0;
+}
+
 struct drm_ioctl_desc virtio_gpu_ioctls[DRM_VIRTIO_NUM_IOCTLS] = {
    DRM_IOCTL_DEF_DRV(VIRTGPU_MAP, virtio_gpu_map_ioctl,
    		  DRM_RENDER_ALLOW),
@@ -875,4 +937,7 @@ struct drm_ioctl_desc virtio_gpu_ioctls[DRM_VIRTIO_NUM_IOCTLS] = {
DRM_IOCTL_DEF_DRV(VIRTGPU_CONTEXT_INIT, virtio_gpu_context_init_ioctl,
    		  DRM_RENDER_ALLOW),
+
+	DRM_IOCTL_DEF_DRV(VIRTGPU_PIN, virtio_gpu_pin_ioctl,
+			  DRM_RENDER_ALLOW),
 };
diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
index f648b0e24447..ae569003d7bc 100644
--- a/drivers/gpu/drm/virtio/virtgpu_object.c
+++ b/drivers/gpu/drm/virtio/virtgpu_object.c
@@ -80,9 +80,9 @@ void virtio_gpu_cleanup_object(struct virtio_gpu_object *bo)
    		kfree(shmem->pages);
    		shmem->pages = NULL;
    		drm_gem_shmem_unpin(&bo->base.base);
+			drm_gem_shmem_free_object(&bo->base.base);
    	}
-		drm_gem_shmem_free_object(&bo->base.base);
    } else if (virtio_gpu_is_vram(bo)) {
    	struct virtio_gpu_object_vram *vram = to_virtio_gpu_vram(bo);
@@ -246,13 +246,6 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
    		goto err_put_objs;
    }
-	ret = virtio_gpu_object_shmem_init(vgdev, bo, &ents, &nents);
-	if (ret != 0) {
-		virtio_gpu_array_put_free(objs);
-		virtio_gpu_free_object(&shmem_obj->base);
-		return ret;
-	}
-
    if (params->blob) {
    	if (params->blob_mem == VIRTGPU_BLOB_MEM_GUEST)
    		bo->guest_blob = true;
@@ -262,8 +255,13 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
    } else if (params->virgl) {
    	virtio_gpu_cmd_resource_create_3d(vgdev, bo, params,
    					  objs, fence);
-		virtio_gpu_object_attach(vgdev, bo, ents, nents);
    } else {
+		ret = virtio_gpu_object_shmem_init(vgdev, bo, &ents, &nents);
+		if (ret != 0) {
+			virtio_gpu_array_put_free(objs);
+			virtio_gpu_free_object(&shmem_obj->base);
+			return ret;
+		}
    	virtio_gpu_cmd_create_resource(vgdev, bo, params,
    				       objs, fence);
    	virtio_gpu_object_attach(vgdev, bo, ents, nents);
@@ -280,3 +278,29 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
    drm_gem_shmem_free_object(&shmem_obj->base);
    return ret;
 }
+
+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++) {
+		struct virtio_gpu_mem_entry *ents;
+		unsigned int nents;
+
+		struct virtio_gpu_object *bo =
+			gem_to_virtio_gpu_obj(objs->objs[i]);
+		if (!bo) {
+			return -EFAULT;
+		}
+
+		ret = virtio_gpu_object_shmem_init(vgdev, bo, &ents, &nents);
+		if (ret != 0) {
+			return -EFAULT;
+		}
+
+		virtio_gpu_object_attach(vgdev, bo, ents, nents);
+	}
+	return 0;
+}
diff --git a/include/uapi/drm/virtgpu_drm.h b/include/uapi/drm/virtgpu_drm.h
index a13e20cc66b4..be6e67f1bb7f 100644
--- a/include/uapi/drm/virtgpu_drm.h
+++ b/include/uapi/drm/virtgpu_drm.h
@@ -48,6 +48,7 @@ extern "C" {
 #define DRM_VIRTGPU_GET_CAPS  0x09
 #define DRM_VIRTGPU_RESOURCE_CREATE_BLOB 0x0a
 #define DRM_VIRTGPU_CONTEXT_INIT 0x0b
+#define DRM_VIRTGPU_PIN 0x0c
#define VIRTGPU_EXECBUF_FENCE_FD_IN	0x01
 #define VIRTGPU_EXECBUF_FENCE_FD_OUT	0x02
@@ -82,6 +83,7 @@ struct drm_virtgpu_execbuffer {
 #define VIRTGPU_PARAM_CROSS_DEVICE 5 /* Cross virtio-device resource sharing  */
 #define VIRTGPU_PARAM_CONTEXT_INIT 6 /* DRM_VIRTGPU_CONTEXT_INIT */
 #define VIRTGPU_PARAM_SUPPORTED_CAPSET_IDs 7 /* Bitmask of supported capability set ids */
+#define VIRTGPU_PARAM_PIN_ON_DEMAND 8 /* is pinning on demand available? */
struct drm_virtgpu_getparam {
    __u64 param;
@@ -196,6 +198,10 @@ struct drm_virtgpu_context_init {
    __u64 ctx_set_params;
 };
+struct drm_virtgpu_pin {
+	__u32 handle;
+};
+
 #define DRM_IOCTL_VIRTGPU_MAP \
    DRM_IOWR(DRM_COMMAND_BASE + DRM_VIRTGPU_MAP, struct drm_virtgpu_map)
@@ -239,6 +245,10 @@ struct drm_virtgpu_context_init {
    DRM_IOWR(DRM_COMMAND_BASE + DRM_VIRTGPU_CONTEXT_INIT,		\
    	struct drm_virtgpu_context_init)
+#define DRM_IOCTL_VIRTGPU_PIN					\
+	DRM_IOWR(DRM_COMMAND_BASE + DRM_VIRTGPU_PIN,		\
+		struct drm_virtgpu_pin)
+
 #if defined(__cplusplus)
 }
 #endif
-- 
2.30.2


    

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[PATCH] drm/virtio: delay pinning the pages till first use