From: Elena Agostini <eagost...@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 <eagost...@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(+) diff --git a/lib/gpudev/gpudev.c b/lib/gpudev/gpudev.c index 9ae36dbae9..eafd5909e3 100644 --- a/lib/gpudev/gpudev.c +++ b/lib/gpudev/gpudev.c @@ -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) { diff --git a/lib/gpudev/gpudev_driver.h b/lib/gpudev/gpudev_driver.h index cb7b101f2f..9049d11280 100644 --- a/lib/gpudev/gpudev_driver.h +++ b/lib/gpudev/gpudev_driver.h @@ -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; }; diff --git a/lib/gpudev/rte_gpudev.h b/lib/gpudev/rte_gpudev.h index fa3f3aad4f..2048133790 100644 --- a/lib/gpudev/rte_gpudev.h +++ b/lib/gpudev/rte_gpudev.h @@ -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. diff --git a/lib/gpudev/version.map b/lib/gpudev/version.map index 2e414c65cc..dce6085e44 100644 --- a/lib/gpudev/version.map +++ b/lib/gpudev/version.map @@ -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; }; -- 2.17.1