[v3] gpudev: expose GPU memory
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Commit Message
From: Elena Agostini <eagostini@nvidia.com>
Enable the possibility to expose a GPU memory area and make it
accessible from the CPU.
GPU memory has to be allocated via rte_gpu_mem_alloc().
This patch allows the gpudev library to expose (and unexpose),
through the GPU driver, a chunk of GPU memory and to return
a memory pointer usable by the CPU to access the GPU memory area.
Changelog:
- Move to pin/unpin naming to expose/unexpose
- Minor changes to function definitions
Signed-off-by: Elena Agostini <eagostini@nvidia.com>
---
lib/gpudev/gpudev.c | 61 ++++++++++++++++++++++++++++++++++++++
lib/gpudev/gpudev_driver.h | 6 ++++
lib/gpudev/rte_gpudev.h | 49 ++++++++++++++++++++++++++++++
lib/gpudev/version.map | 2 ++
4 files changed, 118 insertions(+)
@@ -634,6 +634,67 @@ rte_gpu_mem_unregister(int16_t dev_id, void *ptr)
return GPU_DRV_RET(dev->ops.mem_unregister(dev, ptr));
}
+void *
+rte_gpu_mem_expose(int16_t dev_id, size_t size, void *ptr)
+{
+ struct rte_gpu *dev;
+ void *ptr_out;
+ int ret;
+
+ dev = gpu_get_by_id(dev_id);
+ if (dev == NULL) {
+ GPU_LOG(ERR, "expose mem for invalid device ID %d", dev_id);
+ rte_errno = ENODEV;
+ return NULL;
+ }
+
+ if (dev->ops.mem_expose == NULL) {
+ GPU_LOG(ERR, "mem exposure not supported");
+ rte_errno = ENOTSUP;
+ return NULL;
+ }
+
+ if (ptr == NULL || size == 0) /* dry-run */
+ return NULL;
+
+ ret = GPU_DRV_RET(dev->ops.mem_expose(dev, size, ptr, &ptr_out));
+
+ switch (ret) {
+ case 0:
+ return ptr_out;
+ case -ENOMEM:
+ case -E2BIG:
+ rte_errno = -ret;
+ return NULL;
+ default:
+ rte_errno = -EPERM;
+ return NULL;
+ }
+}
+
+int
+rte_gpu_mem_unexpose(int16_t dev_id, void *ptr)
+{
+ struct rte_gpu *dev;
+
+ dev = gpu_get_by_id(dev_id);
+ if (dev == NULL) {
+ GPU_LOG(ERR, "unexpose mem for invalid device ID %d", dev_id);
+ rte_errno = ENODEV;
+ return -rte_errno;
+ }
+
+ if (dev->ops.mem_unexpose == NULL) {
+ rte_errno = ENOTSUP;
+ return -rte_errno;
+ }
+
+ if (ptr == NULL) /* dry-run */
+ return 0;
+
+ return GPU_DRV_RET(dev->ops.mem_unexpose(dev, ptr));
+}
+
int
rte_gpu_wmb(int16_t dev_id)
{
@@ -31,6 +31,8 @@ typedef int (rte_gpu_mem_alloc_t)(struct rte_gpu *dev, size_t size, void **ptr);
typedef int (rte_gpu_mem_free_t)(struct rte_gpu *dev, void *ptr);
typedef int (rte_gpu_mem_register_t)(struct rte_gpu *dev, size_t size, void *ptr);
typedef int (rte_gpu_mem_unregister_t)(struct rte_gpu *dev, void *ptr);
+typedef int (rte_gpu_mem_expose_t)(struct rte_gpu *dev, size_t size, void *ptr_in, void **ptr_out);
+typedef int (rte_gpu_mem_unexpose_t)(struct rte_gpu *dev, void *ptr);
typedef int (rte_gpu_wmb_t)(struct rte_gpu *dev);
struct rte_gpu_ops {
@@ -46,6 +48,10 @@ struct rte_gpu_ops {
rte_gpu_mem_register_t *mem_register;
/* Unregister CPU memory from device. */
rte_gpu_mem_unregister_t *mem_unregister;
+ /* Pin GPU memory. */
+ rte_gpu_mem_expose_t *mem_expose;
+ /* Unpin GPU memory. */
+ rte_gpu_mem_unexpose_t *mem_unexpose;
/* Enforce GPU write memory barrier. */
rte_gpu_wmb_t *wmb;
};
@@ -447,6 +447,55 @@ int rte_gpu_mem_register(int16_t dev_id, size_t size, void *ptr);
__rte_experimental
int rte_gpu_mem_unregister(int16_t dev_id, void *ptr);
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Expose a chunk of GPU memory to make it accessible from the CPU
+ * using the memory pointer returned by the function.
+ * GPU memory has to be allocated via rte_gpu_mem_alloc().
+ *
+ * @param dev_id
+ * Device ID requiring exposed memory.
+ * @param size
+ * Number of bytes to expose.
+ * Requesting 0 will do nothing.
+ * @param ptr
+ * Pointer to the GPU memory area to be exposed.
+ * NULL is a no-op accepted value.
+
+ * @return
+ * A pointer to the exposed GPU memory usable by the CPU, otherwise NULL and rte_errno is set:
+ * - ENODEV if invalid dev_id
+ * - ENOTSUP if operation not supported by the driver
+ * - E2BIG if size is higher than limit
+ * - ENOMEM if out of space
+ * - EPERM if driver error
+ */
+__rte_experimental
+void *rte_gpu_mem_expose(int16_t dev_id, size_t size, void *ptr);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Unexpose a chunk of GPU memory previously exposed with rte_gpu_mem_expose()
+ *
+ * @param dev_id
+ * Reference device ID.
+ * @param ptr
+ * Pointer to the memory area to be unexposed.
+ * NULL is a no-op accepted value.
+ *
+ * @return
+ * 0 on success, -rte_errno otherwise:
+ * - ENODEV if invalid dev_id
+ * - ENOTSUP if operation not supported by the driver
+ * - EPERM if driver error
+ */
+__rte_experimental
+int rte_gpu_mem_unexpose(int16_t dev_id, void *ptr);
+
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice.
@@ -20,8 +20,10 @@ EXPERIMENTAL {
rte_gpu_init;
rte_gpu_is_valid;
rte_gpu_mem_alloc;
+ rte_gpu_mem_expose;
rte_gpu_mem_free;
rte_gpu_mem_register;
+ rte_gpu_mem_unexpose;
rte_gpu_mem_unregister;
rte_gpu_wmb;
};