03/06/2021 09:18, David Marchand:

Quick pass:

On Wed, Jun 2, 2021 at 10:36 PM Thomas Monjalon [off-list ref] wrote:

quoted

diff --git a/lib/gpudev/gpu_driver.h b/lib/gpudev/gpu_driver.h
new file mode 100644
index 0000000000..5ff609e49d
--- /dev/null
+++ b/lib/gpudev/gpu_driver.h

[...]

quoted

+struct rte_gpu_dev;
+
+typedef int (*gpu_malloc_t)(struct rte_gpu_dev *dev, size_t size, void **ptr);
+typedef int (*gpu_free_t)(struct rte_gpu_dev *dev, void *ptr);
+

Great to see this structure hidden in a driver-only header.

quoted

+struct rte_gpu_dev {

We could have a name[] field here, that will be later pointed at, in
rte_gpu_info.
Who is responsible for deciding of the device name?

The driver is responsible for the name of the device.
Yes I agree to store the name here.

quoted

+       /* Backing device. */
+       struct rte_device *device;
+       /* GPU info structure. */
+       struct rte_gpu_info info;
+       /* Counter of processes using the device. */
+       uint16_t process_cnt;
+       /* If device is currently used or not. */
+       enum rte_gpu_state state;
+       /* FUNCTION: Allocate memory on the GPU. */
+       gpu_malloc_t gpu_malloc;
+       /* FUNCTION: Allocate memory on the CPU visible from the GPU. */
+       gpu_malloc_t gpu_malloc_visible;
+       /* FUNCTION: Free allocated memory on the GPU. */
+       gpu_free_t gpu_free;
+       /* Device interrupt handle. */
+       struct rte_intr_handle *intr_handle;
+       /* Driver-specific private data. */
+       void *dev_private;
+} __rte_cache_aligned;
+
+struct rte_gpu_dev *rte_gpu_dev_allocate(const char *name);
+struct rte_gpu_dev *rte_gpu_dev_get_by_name(const char *name);

Those symbols will have to be marked internal (__rte_internal +
version.map) for drivers to see them.

OK, good catch.

[...]

quoted

+/** Maximum number of GPU engines. */
+#define RTE_GPU_MAX_DEVS UINT16_C(32)

Bleh.
Let's stop with max values.
The iterator _next should return a special value indicating there is
no more devs to list.

I fully agree.
I would like to define gpu_id as an int to simplify comparisons
with error value. int or int16_t ?

quoted

+/** Maximum length of device name. */
+#define RTE_GPU_NAME_MAX_LEN 128

Will be dropped as well.

quoted

+
+/** Flags indicate current state of GPU device. */
+enum rte_gpu_state {
+       RTE_GPU_STATE_UNUSED,        /**< not initialized */
+       RTE_GPU_STATE_INITIALIZED,   /**< initialized */
+};
+
+/** Store a list of info for a given GPU. */
+struct rte_gpu_info {
+       /** GPU device ID. */
+       uint16_t gpu_id;
+       /** Unique identifier name. */
+       char name[RTE_GPU_NAME_MAX_LEN];

const char *name;

Then the gpu generic layer simply fills this with the
rte_gpu_dev->name field I proposed above.

Yes.

quoted

+       /** Total memory available on device. */
+       size_t total_memory;
+       /** Total processors available on device. */
+       int processor_count;
+};