[PATCH v7 3/3] drm/virtio: Support virtgpu exported resources

From: David Stevens
Date: Tue Aug 18 2020 - 03:14:11 EST


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@xxxxxxxxxxxx>
---
drivers/gpu/drm/virtio/virtgpu_drv.c | 3 +
drivers/gpu/drm/virtio/virtgpu_drv.h | 21 ++++++
drivers/gpu/drm/virtio/virtgpu_kms.c | 4 ++
drivers/gpu/drm/virtio/virtgpu_prime.c | 96 +++++++++++++++++++++++++-
drivers/gpu/drm/virtio/virtgpu_vq.c | 55 +++++++++++++++
5 files changed, 176 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
index ab4bed78e656..b039f493bda9 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.c
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
@@ -165,6 +165,7 @@ static unsigned int features[] = {
VIRTIO_GPU_F_VIRGL,
#endif
VIRTIO_GPU_F_EDID,
+ VIRTIO_GPU_F_RESOURCE_UUID,
};
static struct virtio_driver virtio_gpu_driver = {
.feature_table = features,
@@ -202,6 +203,8 @@ 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_mmap = drm_gem_prime_mmap,
+ .gem_prime_export = virtgpu_gem_prime_export,
+ .gem_prime_import = virtgpu_gem_prime_import,
.gem_prime_import_sg_table = virtgpu_gem_prime_import_sg_table,

.gem_create_object = virtio_gpu_create_object,
diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index 49bebdee6d91..cf54b89d9ab1 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -49,6 +49,10 @@
#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;
@@ -71,6 +75,9 @@ struct virtio_gpu_object {
uint32_t hw_res_handle;
bool dumb;
bool created;
+
+ int uuid_state;
+ uuid_t uuid;
};
#define gem_to_virtio_gpu_obj(gobj) \
container_of((gobj), struct virtio_gpu_object, base.base)
@@ -200,6 +207,7 @@ struct virtio_gpu_device {
bool has_virgl_3d;
bool has_edid;
bool has_indirect;
+ bool has_resource_assign_uuid;

struct work_struct config_changed_work;

@@ -210,6 +218,9 @@ struct virtio_gpu_device {
struct virtio_gpu_drv_capset *capsets;
uint32_t num_capsets;
struct list_head cap_cache;
+
+ /* protects resource state when exporting */
+ spinlock_t resource_export_lock;
};

struct virtio_gpu_fpriv {
@@ -335,6 +346,10 @@ void virtio_gpu_dequeue_fence_func(struct work_struct *work);

void virtio_gpu_notify(struct virtio_gpu_device *vgdev);

+int
+virtio_gpu_cmd_resource_assign_uuid(struct virtio_gpu_device *vgdev,
+ struct virtio_gpu_object_array *objs);
+
/* virtgpu_display.c */
void virtio_gpu_modeset_init(struct virtio_gpu_device *vgdev);
void virtio_gpu_modeset_fini(struct virtio_gpu_device *vgdev);
@@ -366,6 +381,12 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
bool virtio_gpu_is_shmem(struct virtio_gpu_object *bo);

/* virtgpu_prime.c */
+struct dma_buf *virtgpu_gem_prime_export(struct drm_gem_object *obj,
+ int flags);
+struct drm_gem_object *virtgpu_gem_prime_import(struct drm_device *dev,
+ struct dma_buf *buf);
+int virtgpu_gem_prime_get_uuid(struct drm_gem_object *obj,
+ uuid_t *uuid);
struct drm_gem_object *virtgpu_gem_prime_import_sg_table(
struct drm_device *dev, struct dma_buf_attachment *attach,
struct sg_table *sgt);
diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c
index 023a030ca7b9..7bcd0c75effa 100644
--- a/drivers/gpu/drm/virtio/virtgpu_kms.c
+++ b/drivers/gpu/drm/virtio/virtgpu_kms.c
@@ -125,6 +125,7 @@ int virtio_gpu_init(struct drm_device *dev)
vgdev->dev = dev->dev;

spin_lock_init(&vgdev->display_info_lock);
+ spin_lock_init(&vgdev->resource_export_lock);
ida_init(&vgdev->ctx_id_ida);
ida_init(&vgdev->resource_ida);
init_waitqueue_head(&vgdev->resp_wq);
@@ -153,6 +154,9 @@ int virtio_gpu_init(struct drm_device *dev)
if (virtio_has_feature(vgdev->vdev, VIRTIO_RING_F_INDIRECT_DESC)) {
vgdev->has_indirect = true;
}
+ if (virtio_has_feature(vgdev->vdev, VIRTIO_GPU_F_RESOURCE_UUID)) {
+ vgdev->has_resource_assign_uuid = true;
+ }

DRM_INFO("features: %cvirgl %cedid\n",
vgdev->has_virgl_3d ? '+' : '-',
diff --git a/drivers/gpu/drm/virtio/virtgpu_prime.c b/drivers/gpu/drm/virtio/virtgpu_prime.c
index 050d24c39a8f..acd14ef73d56 100644
--- a/drivers/gpu/drm/virtio/virtgpu_prime.c
+++ b/drivers/gpu/drm/virtio/virtgpu_prime.c
@@ -23,12 +23,102 @@
*/

#include <drm/drm_prime.h>
+#include <linux/virtio_dma_buf.h>

#include "virtgpu_drv.h"

-/* Empty Implementations as there should not be any other driver for a virtual
- * device that might share buffers with virtgpu
- */
+static int virtgpu_virtio_get_uuid(struct dma_buf *buf,
+ uuid_t *uuid)
+{
+ struct drm_gem_object *obj = buf->priv;
+ 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;
+
+ uuid_copy(uuid, &bo->uuid);
+
+ return 0;
+}
+
+const struct virtio_dma_buf_ops virtgpu_dmabuf_ops = {
+ .ops = {
+ .cache_sgt_mapping = true,
+ .attach = virtio_dma_buf_attach,
+ .detach = drm_gem_map_detach,
+ .map_dma_buf = drm_gem_map_dma_buf,
+ .unmap_dma_buf = drm_gem_unmap_dma_buf,
+ .release = drm_gem_dmabuf_release,
+ .mmap = drm_gem_dmabuf_mmap,
+ .vmap = drm_gem_dmabuf_vmap,
+ .vunmap = drm_gem_dmabuf_vunmap,
+ },
+ .device_attach = drm_gem_map_attach,
+ .get_uuid = virtgpu_virtio_get_uuid,
+};
+
+struct dma_buf *virtgpu_gem_prime_export(struct drm_gem_object *obj,
+ int flags)
+{
+ struct dma_buf *buf;
+ struct drm_device *dev = obj->dev;
+ struct virtio_gpu_device *vgdev = dev->dev_private;
+ struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
+ struct virtio_gpu_object_array *objs;
+ int ret = 0;
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ if (vgdev->has_resource_assign_uuid) {
+ objs = virtio_gpu_array_alloc(1);
+ if (!objs)
+ return ERR_PTR(-ENOMEM);
+ virtio_gpu_array_add_obj(objs, &bo->base.base);
+
+ ret = virtio_gpu_cmd_resource_assign_uuid(vgdev, objs);
+ if (ret)
+ return ERR_PTR(ret);
+ virtio_gpu_notify(vgdev);
+ } else {
+ bo->uuid_state = UUID_INITIALIZATION_FAILED;
+ }
+
+ exp_info.ops = &virtgpu_dmabuf_ops.ops;
+ exp_info.size = obj->size;
+ exp_info.flags = flags;
+ exp_info.priv = obj;
+ exp_info.resv = obj->resv;
+
+ buf = virtio_dma_buf_export(&exp_info);
+ if (IS_ERR(buf))
+ return buf;
+
+ drm_dev_get(dev);
+ drm_gem_object_get(obj);
+
+ return buf;
+}
+
+struct drm_gem_object *virtgpu_gem_prime_import(struct drm_device *dev,
+ struct dma_buf *buf)
+{
+ struct drm_gem_object *obj;
+
+ if (buf->ops == &virtgpu_dmabuf_ops.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;
+ }
+ }
+
+ return drm_gem_prime_import(dev, buf);
+}

struct drm_gem_object *virtgpu_gem_prime_import_sg_table(
struct drm_device *dev, struct dma_buf_attachment *attach,
diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 9e663a5d9952..823223b0bb75 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -1107,3 +1107,58 @@ 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_object *obj =
+ gem_to_virtio_gpu_obj(vbuf->objs->objs[0]);
+ struct virtio_gpu_resp_resource_uuid *resp =
+ (struct virtio_gpu_resp_resource_uuid *)vbuf->resp_buf;
+ uint32_t resp_type = le32_to_cpu(resp->hdr.type);
+
+ spin_lock(&vgdev->resource_export_lock);
+ WARN_ON(obj->uuid_state != UUID_INITIALIZING);
+
+ 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);
+
+ wake_up_all(&vgdev->resp_wq);
+}
+
+int
+virtio_gpu_cmd_resource_assign_uuid(struct virtio_gpu_device *vgdev,
+ struct virtio_gpu_object_array *objs)
+{
+ struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(objs->objs[0]);
+ 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);
+ virtio_gpu_array_put_free(objs);
+ 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);
+
+ vbuf->objs = objs;
+ virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
+ return 0;
+}
--
2.28.0.220.ged08abb693-goog