FROMLIST: drm/virtio: Support virtgpu exported resources

Add support for UUID-based resource sharing mechanism to virtgpu. This
implements the new virtgpu commands and hooks them up to dma-buf's
get_uuid callback.

Signed-off-by: David Stevens <stevensd@chromium.org>
(am from https://patchwork.kernel.org/patch/11431393/)

Fixes:
 - Shove virtio_gpu_object in data_buf since objs isn't available
 - Remove virtio specific dma_buf_ops, but make sure that
   virtio_gpu_dma_buf_to_handle continues to work. This effectively
   reverts b7f70332c5c52f614641a33418b9b2a16204f4e6.

BUG=b:136269340
TEST=boot ARCVM and launch play store

Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/2059087
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
Commit-Queue: David Stevens <stevensd@chromium.org>
Tested-by: David Stevens <stevensd@chromium.org>
Bug: 153580313
Signed-off-by: Lingfeng Yang <lfy@google.com>
Change-Id: I621b2a123679320da153f665b435cd3810fb002e

6 files changed, 111 insertions, 27 deletions

diff --git a/virtio_gpu/virtgpu_drv.c b/virtio_gpu/virtgpu_drv.c
index 4b5107c..eba4a46 100644
--- a/virtio_gpu/virtgpu_drv.c
+++ b/virtio_gpu/virtgpu_drv.c
@@ -179,6 +179,7 @@ static unsigned int features[] = {
 	VIRTIO_GPU_F_VIRGL,
 #endif
 	VIRTIO_GPU_F_EDID,
+	VIRTIO_GPU_F_RESOURCE_UUID,
 	VIRTIO_GPU_F_RESOURCE_V2,
 	VIRTIO_GPU_F_SHARED_GUEST,
 	VIRTIO_GPU_F_HOST_COHERENT,
@@ -229,12 +230,13 @@ static struct drm_driver driver = {
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 	.gem_prime_export = virtgpu_gem_prime_export,
-	.gem_prime_import = virtgpu_gem_prime_import,
+	.gem_prime_import = drm_gem_prime_import,
 	.gem_prime_get_sg_table = virtgpu_gem_prime_get_sg_table,
 	.gem_prime_import_sg_table = virtgpu_gem_prime_import_sg_table,
 	.gem_prime_vmap = virtgpu_gem_prime_vmap,
 	.gem_prime_vunmap = virtgpu_gem_prime_vunmap,
 	.gem_prime_mmap = virtgpu_gem_prime_mmap,
+	.gem_prime_get_uuid = virtgpu_gem_prime_get_uuid,
 
 	.gem_free_object_unlocked = virtio_gpu_gem_free_object,
 	.gem_open_object = virtio_gpu_gem_object_open,
diff --git a/virtio_gpu/virtgpu_drv.h b/virtio_gpu/virtgpu_drv.h
index 2fabee4..fbf9f39 100644
--- a/virtio_gpu/virtgpu_drv.h
+++ b/virtio_gpu/virtgpu_drv.h
@@ -50,6 +50,10 @@
 #define DRIVER_MINOR 1
 #define DRIVER_PATCHLEVEL 0
 
+#define UUID_INITIALIZING 0
+#define UUID_INITIALIZED 1
+#define UUID_INITIALIZATION_FAILED 2
+
 struct virtio_gpu_object_params {
 	uint32_t format;
 	uint32_t width;
@@ -93,6 +97,9 @@ struct virtio_gpu_object {
 	bool created;
     enum virtio_gpu_memory_type guest_memory_type;
 	enum virtio_gpu_caching_type caching_type;
+
+	int uuid_state;
+	uuid_t uuid;
 };
 #define gem_to_virtio_gpu_obj(gobj) \
 	container_of((gobj), struct virtio_gpu_object, gem_base)
@@ -244,6 +251,8 @@ struct virtio_gpu_device {
 
 	struct idr request_idr;
 	spinlock_t request_idr_lock;
+
+	spinlock_t resource_export_lock;
 };
 
 struct virtio_gpu_fpriv {
@@ -383,6 +392,10 @@ void virtio_gpu_dequeue_ctrl_func(struct work_struct *work);
 void virtio_gpu_dequeue_cursor_func(struct work_struct *work);
 void virtio_gpu_dequeue_fence_func(struct work_struct *work);
 
+int
+virtio_gpu_cmd_resource_assign_uuid(struct virtio_gpu_device *vgdev,
+				    struct virtio_gpu_object *bo);
+
 /* virtio_gpu_display.c */
 int virtio_gpu_framebuffer_init(struct drm_device *dev,
 				struct virtio_gpu_framebuffer *vgfb,
@@ -430,8 +443,6 @@ extern const struct dma_buf_ops virtgpu_dmabuf_ops;
 struct dma_buf *virtgpu_gem_prime_export(struct drm_device *dev,
 					 struct drm_gem_object *obj,
 					 int flags);
-struct drm_gem_object *virtgpu_gem_prime_import(struct drm_device *dev,
-						struct dma_buf *buf);
 struct sg_table *virtgpu_gem_prime_get_sg_table(struct drm_gem_object *obj);
 struct drm_gem_object *virtgpu_gem_prime_import_sg_table(
 	struct drm_device *dev, struct dma_buf_attachment *attach,
@@ -440,6 +451,8 @@ void *virtgpu_gem_prime_vmap(struct drm_gem_object *obj);
 void virtgpu_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
 int virtgpu_gem_prime_mmap(struct drm_gem_object *obj,
 			   struct vm_area_struct *vma);
+int virtgpu_gem_prime_get_uuid(struct drm_gem_object *obj,
+			       uuid_t *uuid);
 
 static inline struct virtio_gpu_object*
 virtio_gpu_object_ref(struct virtio_gpu_object *bo)
diff --git a/virtio_gpu/virtgpu_kms.c b/virtio_gpu/virtgpu_kms.c
index eab2df8..9b9535d 100644
--- a/virtio_gpu/virtgpu_kms.c
+++ b/virtio_gpu/virtgpu_kms.c
@@ -134,6 +134,7 @@ int virtio_gpu_init(struct drm_device *dev)
 
 	spin_lock_init(&vgdev->display_info_lock);
 	spin_lock_init(&vgdev->request_idr_lock);
+	spin_lock_init(&vgdev->resource_export_lock);
 	ida_init(&vgdev->ctx_id_ida);
 	ida_init(&vgdev->resource_ida);
 	idr_init(&vgdev->request_idr);
@@ -160,6 +161,10 @@ int virtio_gpu_init(struct drm_device *dev)
 		vgdev->has_edid = true;
 		DRM_INFO("EDID support available.\n");
 	}
+	if (virtio_has_feature(vgdev->vdev, VIRTIO_GPU_F_RESOURCE_UUID)) {
+		vgdev->has_resource_assign_uuid = true;
+		DRM_INFO("Virtio cross device support available.\n");
+	}
 
 	if (virtio_has_feature(vgdev->vdev, VIRTIO_GPU_F_RESOURCE_V2)) {
 		if (virtio_has_feature(vgdev->vdev, VIRTIO_GPU_F_HOST_COHERENT)) {
diff --git a/virtio_gpu/virtgpu_object.c b/virtio_gpu/virtgpu_object.c
index 17d297b..3a3ac9d 100644
--- a/virtio_gpu/virtgpu_object.c
+++ b/virtio_gpu/virtgpu_object.c
@@ -27,6 +27,7 @@
 
 #include <drm/ttm/ttm_execbuf_util.h>
 #include <linux/dma-buf.h>
+#include <linux/uuid.h>
 #include "virtgpu_drv.h"
 
 static int virtio_gpu_virglrenderer_workaround = 1;
@@ -285,8 +286,9 @@ int virtio_gpu_dma_buf_to_handle(struct dma_buf *dma_buf, bool no_wait,
 {
 	struct virtio_gpu_object *qobj;
 	struct virtio_gpu_device *vgdev;
+	uuid_t uuid;
 
-	if (dma_buf->ops != &virtgpu_dmabuf_ops)
+	if (dma_buf_get_uuid(dma_buf, &uuid) != 0)
 		return -EINVAL;
 
 	qobj = gem_to_virtio_gpu_obj(dma_buf->priv);
diff --git a/virtio_gpu/virtgpu_prime.c b/virtio_gpu/virtgpu_prime.c
index 3b43c4c..ddcc5cd 100644
--- a/virtio_gpu/virtgpu_prime.c
+++ b/virtio_gpu/virtgpu_prime.c
@@ -41,37 +41,38 @@ const struct dma_buf_ops virtgpu_dmabuf_ops =  {
 	.vunmap = drm_gem_dmabuf_vunmap,
 };
 
-struct dma_buf *virtgpu_gem_prime_export(struct drm_device *dev,
-					 struct drm_gem_object *obj,
-					 int flags)
+int virtgpu_gem_prime_get_uuid(struct drm_gem_object *obj,
+			       uuid_t *uuid)
 {
-	struct dma_buf *buf;
+	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
+	struct virtio_gpu_device *vgdev = obj->dev->dev_private;
+
+	wait_event(vgdev->resp_wq, bo->uuid_state != UUID_INITIALIZING);
+	if (bo->uuid_state != UUID_INITIALIZED)
+		return -ENODEV;
 
-	buf = drm_gem_prime_export(dev, obj, flags);
-	if (!IS_ERR(buf))
-		buf->ops = &virtgpu_dmabuf_ops;
+	uuid_copy(uuid, &bo->uuid);
 
-	return buf;
+	return 0;
 }
 
-struct drm_gem_object *virtgpu_gem_prime_import(struct drm_device *dev,
-						struct dma_buf *buf)
+struct dma_buf *virtgpu_gem_prime_export(struct drm_device *dev,
+					 struct drm_gem_object *obj,
+					 int flags)
 {
-	struct drm_gem_object *obj;
-
-	if (buf->ops == &virtgpu_dmabuf_ops) {
-		obj = buf->priv;
-		if (obj->dev == dev) {
-			/*
-			 * Importing dmabuf exported from our own gem increases
-			 * refcount on gem itself instead of f_count of dmabuf.
-			 */
-			drm_gem_object_get(obj);
-			return obj;
-		}
+	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
+	struct virtio_gpu_device *vgdev = dev->dev_private;
+	int ret = 0;
+
+	if (vgdev->has_resource_assign_uuid) {
+		ret = virtio_gpu_cmd_resource_assign_uuid(vgdev, bo);
+		if (ret)
+			return ERR_PTR(ret);
+	} else {
+		bo->uuid_state = UUID_INITIALIZATION_FAILED;
 	}
 
-	return drm_gem_prime_import(dev, buf);
+	return drm_gem_prime_export(dev, obj, flags);
 }
 
 struct sg_table *virtgpu_gem_prime_get_sg_table(struct drm_gem_object *obj)
diff --git a/virtio_gpu/virtgpu_vq.c b/virtio_gpu/virtgpu_vq.c
index d6b657c..dcec716 100644
--- a/virtio_gpu/virtgpu_vq.c
+++ b/virtio_gpu/virtgpu_vq.c
@@ -1210,3 +1210,64 @@ void virtio_gpu_cursor_ping(struct virtio_gpu_device *vgdev,
 	memcpy(cur_p, &output->cursor, sizeof(output->cursor));
 	virtio_gpu_queue_cursor(vgdev, vbuf);
 }
+
+static void virtio_gpu_cmd_resource_uuid_cb(struct virtio_gpu_device *vgdev,
+					    struct virtio_gpu_vbuffer *vbuf)
+{
+	struct virtio_gpu_resp_resource_uuid *resp =
+		(struct virtio_gpu_resp_resource_uuid *)vbuf->resp_buf;
+	struct virtio_gpu_object *obj =
+		(struct virtio_gpu_object *)vbuf->data_buf;
+	uint32_t resp_type = le32_to_cpu(resp->hdr.type);
+
+	/*
+	 * Keeps the data_buf, which points to this virtio_gpu_object, from
+	 * getting kfree'd after this cb returns.
+	 */
+	vbuf->data_buf = NULL;
+
+	spin_lock(&vgdev->resource_export_lock);
+	if (resp_type == VIRTIO_GPU_RESP_OK_RESOURCE_UUID &&
+			obj->uuid_state == UUID_INITIALIZING) {
+		memcpy(&obj->uuid.b, resp->uuid, sizeof(obj->uuid.b));
+		obj->uuid_state = UUID_INITIALIZED;
+	} else {
+		obj->uuid_state = UUID_INITIALIZATION_FAILED;
+	}
+	spin_unlock(&vgdev->resource_export_lock);
+
+	drm_gem_object_put_unlocked(&obj->gem_base);
+	wake_up_all(&vgdev->resp_wq);
+}
+
+int
+virtio_gpu_cmd_resource_assign_uuid(struct virtio_gpu_device *vgdev,
+				    struct virtio_gpu_object *bo)
+{
+	struct virtio_gpu_resource_assign_uuid *cmd_p;
+	struct virtio_gpu_vbuffer *vbuf;
+	struct virtio_gpu_resp_resource_uuid *resp_buf;
+
+	resp_buf = kzalloc(sizeof(*resp_buf), GFP_KERNEL);
+	if (!resp_buf) {
+		spin_lock(&vgdev->resource_export_lock);
+		bo->uuid_state = UUID_INITIALIZATION_FAILED;
+		spin_unlock(&vgdev->resource_export_lock);
+		return -ENOMEM;
+	}
+
+	cmd_p = virtio_gpu_alloc_cmd_resp(vgdev,
+		virtio_gpu_cmd_resource_uuid_cb, &vbuf, sizeof(*cmd_p),
+		sizeof(struct virtio_gpu_resp_resource_uuid), resp_buf);
+	memset(cmd_p, 0, sizeof(*cmd_p));
+
+	cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_RESOURCE_ASSIGN_UUID);
+	cmd_p->resource_id = cpu_to_le32(bo->hw_res_handle);
+
+	/* Reuse the data_buf pointer for the object pointer. */
+	vbuf->data_buf = bo;
+	drm_gem_object_get(&bo->gem_base);
+	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
+	return 0;
+}
+