drm/virtio: rework virtio_gpu_execbuffer_ioctl fencing

Rework fencing workflow, starting with virtio_gpu_execbuffer_ioctl.
Stop using ttm helpers, use the virtio_gpu_array_* helpers (which work
on the reservation objects directly) instead.

Also store the object array in struct virtio_gpu_vbuffer, so we
explicitly keep a reference of all buffers used instead of depending
on ttm_bo_put() checking whenever the object is actually idle before
releasing it.

New workflow:

 (1) All gem objects needed by a command are added to a
     virtio_gpu_object_array.
 (2) All reservation objects will be locked (virtio_gpu_array_lock_resv).
 (3) virtio_gpu_fence_emit() completes fence initialization.
 (4) fence gets added to the objects, reservation objects are unlocked
     (virtio_gpu_array_add_fence, virtio_gpu_array_unlock_resv).
 (5) virtio command is submitted to the host.
 (6) The completion callback (virtio_gpu_dequeue_ctrl_func)
     will drop object references and free virtio_gpu_object_array.

v6: rewrite most of the patch.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20190829103301.3539-9-kraxel@redhat.com

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index b6bd2b1..f4f843a 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -121,9 +121,9 @@ struct virtio_gpu_vbuffer {
 
        char *resp_buf;
        int resp_size;
-
        virtio_gpu_resp_cb resp_cb;
 
+       struct virtio_gpu_object_array *objs;
        struct list_head list;
 };
 
@@ -318,7 +318,9 @@ void virtio_gpu_cmd_context_detach_resource(struct virtio_gpu_device *vgdev,
                                            uint32_t resource_id);
 void virtio_gpu_cmd_submit(struct virtio_gpu_device *vgdev,
                           void *data, uint32_t data_size,
-                          uint32_t ctx_id, struct virtio_gpu_fence *fence);
+                          uint32_t ctx_id,
+                          struct virtio_gpu_object_array *objs,
+                          struct virtio_gpu_fence *fence);
 void virtio_gpu_cmd_transfer_from_host_3d(struct virtio_gpu_device *vgdev,
                                          uint32_t resource_id, uint32_t ctx_id,
                                          uint64_t offset, uint32_t level,

diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 7f1775b..61b1b55 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -107,16 +107,11 @@ static int virtio_gpu_execbuffer_ioctl(struct drm_device *dev, void *data,
        struct drm_virtgpu_execbuffer *exbuf = data;
        struct virtio_gpu_device *vgdev = dev->dev_private;
        struct virtio_gpu_fpriv *vfpriv = drm_file->driver_priv;
-       struct drm_gem_object *gobj;
        struct virtio_gpu_fence *out_fence;
-       struct virtio_gpu_object *qobj;
        int ret;
        uint32_t *bo_handles = NULL;
        void __user *user_bo_handles = NULL;
-       struct list_head validate_list;
-       struct ttm_validate_buffer *buflist = NULL;
-       int i;
-       struct ww_acquire_ctx ticket;
+       struct virtio_gpu_object_array *buflist = NULL;
        struct sync_file *sync_file;
        int in_fence_fd = exbuf->fence_fd;
        int out_fence_fd = -1;
@@ -157,15 +152,10 @@ static int virtio_gpu_execbuffer_ioctl(struct drm_device *dev, void *data,
                        return out_fence_fd;
        }
 
-       INIT_LIST_HEAD(&validate_list);
        if (exbuf->num_bo_handles) {
-
                bo_handles = kvmalloc_array(exbuf->num_bo_handles,
-                                          sizeof(uint32_t), GFP_KERNEL);
-               buflist = kvmalloc_array(exbuf->num_bo_handles,
-                                          sizeof(struct ttm_validate_buffer),
-                                          GFP_KERNEL | __GFP_ZERO);
-               if (!bo_handles || !buflist) {
+                                           sizeof(uint32_t), GFP_KERNEL);
+               if (!bo_handles) {
                        ret = -ENOMEM;
                        goto out_unused_fd;
                }
@@ -177,25 +167,21 @@ static int virtio_gpu_execbuffer_ioctl(struct drm_device *dev, void *data,
                        goto out_unused_fd;
                }
 
-               for (i = 0; i < exbuf->num_bo_handles; i++) {
-                       gobj = drm_gem_object_lookup(drm_file, bo_handles[i]);
-                       if (!gobj) {
-                               ret = -ENOENT;
-                               goto out_unused_fd;
-                       }
-
-                       qobj = gem_to_virtio_gpu_obj(gobj);
-                       buflist[i].bo = &qobj->tbo;
-
-                       list_add(&buflist[i].head, &validate_list);
+               buflist = virtio_gpu_array_from_handles(drm_file, bo_handles,
+                                                       exbuf->num_bo_handles);
+               if (!buflist) {
+                       ret = -ENOENT;
+                       goto out_unused_fd;
                }
                kvfree(bo_handles);
                bo_handles = NULL;
        }
 
-       ret = virtio_gpu_object_list_validate(&ticket, &validate_list);
-       if (ret)
-               goto out_free;
+       if (buflist) {
+               ret = virtio_gpu_array_lock_resv(buflist);
+               if (ret)
+                       goto out_unused_fd;
+       }
 
        buf = memdup_user(u64_to_user_ptr(exbuf->command), exbuf->size);
        if (IS_ERR(buf)) {
@@ -222,24 +208,18 @@ static int virtio_gpu_execbuffer_ioctl(struct drm_device *dev, void *data,
        }
 
        virtio_gpu_cmd_submit(vgdev, buf, exbuf->size,
-                             vfpriv->ctx_id, out_fence);
-
-       ttm_eu_fence_buffer_objects(&ticket, &validate_list, &out_fence->f);
-
-       /* fence the command bo */
-       virtio_gpu_unref_list(&validate_list);
-       kvfree(buflist);
+                             vfpriv->ctx_id, buflist, out_fence);
        return 0;
 
 out_memdup:
        kfree(buf);
 out_unresv:
-       ttm_eu_backoff_reservation(&ticket, &validate_list);
-out_free:
-       virtio_gpu_unref_list(&validate_list);
+       if (buflist)
+               virtio_gpu_array_unlock_resv(buflist);
 out_unused_fd:
        kvfree(bo_handles);
-       kvfree(buflist);
+       if (buflist)
+               virtio_gpu_array_put_free(buflist);
 
        if (out_fence_fd >= 0)
                put_unused_fd(out_fence_fd);

diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index e41c961..5137dcf 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -192,7 +192,7 @@ void virtio_gpu_dequeue_ctrl_func(struct work_struct *work)
        } while (!virtqueue_enable_cb(vgdev->ctrlq.vq));
        spin_unlock(&vgdev->ctrlq.qlock);
 
-       list_for_each_entry_safe(entry, tmp, &reclaim_list, list) {
+       list_for_each_entry(entry, &reclaim_list, list) {
                resp = (struct virtio_gpu_ctrl_hdr *)entry->resp_buf;
 
                trace_virtio_gpu_cmd_response(vgdev->ctrlq.vq, resp);
@@ -219,14 +219,18 @@ void virtio_gpu_dequeue_ctrl_func(struct work_struct *work)
                }
                if (entry->resp_cb)
                        entry->resp_cb(vgdev, entry);
-
-               list_del(&entry->list);
-               free_vbuf(vgdev, entry);
        }
        wake_up(&vgdev->ctrlq.ack_queue);
 
        if (fence_id)
                virtio_gpu_fence_event_process(vgdev, fence_id);
+
+       list_for_each_entry_safe(entry, tmp, &reclaim_list, list) {
+               if (entry->objs)
+                       virtio_gpu_array_put_free(entry->objs);
+               list_del(&entry->list);
+               free_vbuf(vgdev, entry);
+       }
 }
 
 void virtio_gpu_dequeue_cursor_func(struct work_struct *work)
@@ -337,6 +341,10 @@ again:
 
        if (fence)
                virtio_gpu_fence_emit(vgdev, hdr, fence);
+       if (vbuf->objs) {
+               virtio_gpu_array_add_fence(vbuf->objs, &fence->f);
+               virtio_gpu_array_unlock_resv(vbuf->objs);
+       }
        notify = virtio_gpu_queue_ctrl_buffer_locked(vgdev, vbuf);
        spin_unlock(&vgdev->ctrlq.qlock);
        if (notify)
@@ -940,7 +948,9 @@ void virtio_gpu_cmd_transfer_from_host_3d(struct virtio_gpu_device *vgdev,
 
 void virtio_gpu_cmd_submit(struct virtio_gpu_device *vgdev,
                           void *data, uint32_t data_size,
-                          uint32_t ctx_id, struct virtio_gpu_fence *fence)
+                          uint32_t ctx_id,
+                          struct virtio_gpu_object_array *objs,
+                          struct virtio_gpu_fence *fence)
 {
        struct virtio_gpu_cmd_submit *cmd_p;
        struct virtio_gpu_vbuffer *vbuf;
@@ -950,6 +960,7 @@ void virtio_gpu_cmd_submit(struct virtio_gpu_device *vgdev,
 
        vbuf->data_buf = data;
        vbuf->data_size = data_size;
+       vbuf->objs = objs;
 
        cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_SUBMIT_3D);
        cmd_p->hdr.ctx_id = cpu_to_le32(ctx_id);