rte_memory.h(3) DPDK rte_memory.h(3) NAME rte_memory.h SYNOPSIS #include <stdint.h> #include <stddef.h> #include <stdio.h> #include <rte_bitops.h> #include <rte_common.h> #include <rte_config.h> #include <rte_eal_memconfig.h> #include <rte_fbarray.h> Data Structures struct rte_memseg struct rte_memseg_list Macros #define SOCKET_ID_ANY -1 #define RTE_MEMSEG_FLAG_DO_NOT_FREE RTE_BIT32(0) #define RTE_MEMSEG_FLAG_DIRTY RTE_BIT32(1) #define RTE_MEM_EVENT_CALLBACK_NAME_LEN 64 #define RTE_MEM_ALLOC_VALIDATOR_NAME_LEN 64 Typedefs typedef int(* rte_memseg_walk_t) (const struct rte_memseg_list *msl, const struct rte_memseg *ms, void *arg) typedef int(* rte_memseg_contig_walk_t) (const struct rte_memseg_list *msl, const struct rte_memseg *ms, size_t len, void *arg) typedef int(* rte_memseg_list_walk_t) (const struct rte_memseg_list *msl, void *arg) typedef void(* rte_mem_event_callback_t) (enum rte_mem_event event_type, const void *addr, size_t len, void *arg) typedef int(* rte_mem_alloc_validator_t) (int socket_id, size_t cur_limit, size_t new_len) Enumerations enum rte_mem_event { RTE_MEM_EVENT_ALLOC = 0, RTE_MEM_EVENT_FREE } Functions int rte_mem_lock_page (const void *virt) phys_addr_t rte_mem_virt2phy (const void *virt) rte_iova_t rte_mem_virt2iova (const void *virt) void * rte_mem_iova2virt (rte_iova_t iova) struct rte_memseg * rte_mem_virt2memseg (const void *virt, const struct rte_memseg_list *msl) struct rte_memseg_list * rte_mem_virt2memseg_list (const void *virt) int rte_memseg_walk (rte_memseg_walk_t func, void *arg) int rte_memseg_contig_walk (rte_memseg_contig_walk_t func, void *arg) int rte_memseg_list_walk (rte_memseg_list_walk_t func, void *arg) __rte_locks_excluded(rte_mcfg_mem_get_lock()) int rte_memseg_walk_thread_unsafe (rte_memseg_walk_t func, void *arg) int rte_memseg_contig_walk_thread_unsafe (rte_memseg_contig_walk_t func, void *arg) int rte_memseg_list_walk_thread_unsafe (rte_memseg_list_walk_t func, void *arg) int rte_memseg_get_fd (const struct rte_memseg *ms) int rte_memseg_get_fd_thread_unsafe (const struct rte_memseg *ms) int rte_memseg_get_fd_offset (const struct rte_memseg *ms, size_t *offset) int rte_memseg_get_fd_offset_thread_unsafe (const struct rte_memseg *ms, size_t *offset) int rte_extmem_register (void *va_addr, size_t len, rte_iova_t iova_ad- drs[], unsigned int n_pages, size_t page_sz) int rte_extmem_unregister (void *va_addr, size_t len) int rte_extmem_attach (void *va_addr, size_t len) int rte_extmem_detach (void *va_addr, size_t len) void rte_dump_physmem_layout (FILE *f) uint64_t rte_eal_get_physmem_size (void) unsigned rte_memory_get_nchannel (void) unsigned rte_memory_get_nrank (void) int rte_mem_check_dma_mask (uint8_t maskbits) int rte_mem_check_dma_mask_thread_unsafe (uint8_t maskbits) void rte_mem_set_dma_mask (uint8_t maskbits) int rte_eal_using_phys_addrs (void) int rte_mem_event_callback_register (const char *name, rte_mem_event_call- back_t clb, void *arg) int rte_mem_event_callback_unregister (const char *name, void *arg) int rte_mem_alloc_validator_register (const char *name, rte_mem_alloc_val- idator_t clb, int socket_id, size_t limit) Register validator callback for memory allocations. int rte_mem_alloc_validator_unregister (const char *name, int socket_id) Unregister validator callback for memory allocations. __rte_experimental void rte_memzero_explicit (void *dst, size_t sz) static __rte_experimental bool rte_memeq_timingsafe (const void *a, const void *b, size_t n) Detailed Description Memory-related RTE API. Definition in file rte_memory.h. Macro Definition Documentation #define SOCKET_ID_ANY -1 Any NUMA socket. Definition at line 39 of file rte_memory.h. #define RTE_MEMSEG_FLAG_DO_NOT_FREE RTE_BIT32(0) Prevent this segment from being freed back to the OS. Definition at line 42 of file rte_memory.h. #define RTE_MEMSEG_FLAG_DIRTY RTE_BIT32(1) This segment is not filled with zeros. Definition at line 44 of file rte_memory.h. #define RTE_MEM_EVENT_CALLBACK_NAME_LEN 64 maximum length of callback name Definition at line 610 of file rte_memory.h. #define RTE_MEM_ALLOC_VALIDATOR_NAME_LEN 64 maximum length of alloc validator name Definition at line 666 of file rte_memory.h. Typedef Documentation typedef int(* rte_memseg_walk_t) (const struct rte_memseg_list *msl, const struct rte_memseg *ms, void *arg) Memseg walk function prototype. Returning 0 will continue walk Returning 1 will stop the walk Returning -1 will stop the walk and report error Definition at line 167 of file rte_memory.h. typedef int(* rte_memseg_contig_walk_t) (const struct rte_memseg_list *msl, const struct rte_memseg *ms, size_t len, void *arg) Memseg contig walk function prototype. This will trigger a callback on every VA-contiguous area starting at memseg ms, so total valid VA space at each callback call will be [ms->addr, ms->addr + len). Returning 0 will continue walk Returning 1 will stop the walk Returning -1 will stop the walk and report error Definition at line 179 of file rte_memory.h. typedef int(* rte_memseg_list_walk_t) (const struct rte_memseg_list *msl, void *arg) Memseg list walk function prototype. This will trigger a callback on every allocated memseg list. Returning 0 will continue walk Returning 1 will stop the walk Returning -1 will stop the walk and report error Definition at line 190 of file rte_memory.h. typedef void(* rte_mem_event_callback_t) (enum rte_mem_event event_type, const void *addr, size_t len, void *arg) Function typedef used to register callbacks for memory events. Definition at line 615 of file rte_memory.h. typedef int(* rte_mem_alloc_validator_t) (int socket_id, size_t cur_limit, size_t new_len) Function typedef used to register memory allocation validation callbacks. Returning 0 will allow allocation attempt to continue. Returning -1 will prevent allocation from succeeding. Definition at line 673 of file rte_memory.h. Enumeration Type Documentation enum rte_mem_event Enum indicating which kind of memory event has happened. Used by callbacks to distinguish between memory allocations and deallocations. Enumerator RTE_MEM_EVENT_ALLOC Allocation event. RTE_MEM_EVENT_FREE Deallocation event. Definition at line 605 of file rte_memory.h. Function Documentation int rte_mem_lock_page (const void * virt) Lock page in physical memory and prevent from swapping. Parameters virt The virtual address. Returns 0 on success, negative on error. phys_addr_t rte_mem_virt2phy (const void * virt) Get physical address of any mapped virtual address in the current process. It is found by browsing the /proc/self/pagemap special file. The page must be locked. Parameters virt The virtual address. Returns The physical address or RTE_BAD_IOVA on error. rte_iova_t rte_mem_virt2iova (const void * virt) Get IO virtual address of any mapped virtual address in the current process. Note This function will not check internal page table. Instead, in IOVA as PA mode, it will fall back to getting real physical address (which may not match the expected IOVA, such as what was specified for external memory). Parameters virt The virtual address. Returns The IO address or RTE_BAD_IOVA on error. void * rte_mem_iova2virt (rte_iova_t iova) Get virtual memory address corresponding to iova address. Note This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions. Parameters iova The iova address. Returns Virtual address corresponding to iova address (or NULL if address does not exist within DPDK memory map). struct rte_memseg * rte_mem_virt2memseg (const void * virt, const struct rte_memseg_list * msl) Get memseg to which a particular virtual address belongs. Parameters virt The virtual address. msl The memseg list in which to look up based on virt address (can be NULL). Returns Memseg pointer on success, or NULL on error. struct rte_memseg_list * rte_mem_virt2memseg_list (const void * virt) Get memseg list corresponding to virtual memory address. Parameters virt The virtual address. Returns Memseg list to which this virtual address belongs to. int rte_memseg_walk (rte_memseg_walk_t func, void * arg) Walk list of all memsegs. Note This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions. This function will also walk through externally allocated segments. It is up to the user to decide whether to skip through these segments. Parameters func Iterator function arg Argument passed to iterator Returns 0 if walked over the entire list 1 if stopped by the user -1 if user function reported error int rte_memseg_contig_walk (rte_memseg_contig_walk_t func, void * arg) Walk each VA-contiguous area. Note This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions. This function will also walk through externally allocated segments. It is up to the user to decide whether to skip through these segments. Parameters func Iterator function arg Argument passed to iterator Returns 0 if walked over the entire list 1 if stopped by the user -1 if user function reported error int rte_memseg_list_walk (rte_memseg_list_walk_t func, void * arg) Walk each allocated memseg list. Note This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions. This function will also walk through externally allocated segments. It is up to the user to decide whether to skip through these segments. Parameters func Iterator function arg Argument passed to iterator Returns 0 if walked over the entire list 1 if stopped by the user -1 if user function reported error int rte_memseg_walk_thread_unsafe (rte_memseg_walk_t func, void * arg) Walk list of all memsegs without performing any locking. Note This function does not perform any locking, and is only safe to call from within memory-related callback functions. Parameters func Iterator function arg Argument passed to iterator Returns 0 if walked over the entire list 1 if stopped by the user -1 if user function reported error int rte_memseg_contig_walk_thread_unsafe (rte_memseg_contig_walk_t func, void * arg) Walk each VA-contiguous area without performing any locking. Note This function does not perform any locking, and is only safe to call from within memory-related callback functions. Parameters func Iterator function arg Argument passed to iterator Returns 0 if walked over the entire list 1 if stopped by the user -1 if user function reported error int rte_memseg_list_walk_thread_unsafe (rte_memseg_list_walk_t func, void * arg) Walk each allocated memseg list without performing any locking. Note This function does not perform any locking, and is only safe to call from within memory-related callback functions. Parameters func Iterator function arg Argument passed to iterator Returns 0 if walked over the entire list 1 if stopped by the user -1 if user function reported error int rte_memseg_get_fd (const struct rte_memseg * ms) Return file descriptor associated with a particular memseg (if available). Note This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions. This returns an internal file descriptor. Performing any operations on this file descriptor is inherently dangerous, so it should be treated as read-only for all intents and purposes. Parameters ms A pointer to memseg for which to get file descriptor. Returns Valid file descriptor in case of success. -1 in case of error, with rte_errno set to the following values: * EINVAL - ms pointer was NULL or did not point to a valid memseg * ENODEV - ms fd is not available * ENOENT - ms is an unused segment * ENOTSUP - segment fd's are not supported int rte_memseg_get_fd_thread_unsafe (const struct rte_memseg * ms) Return file descriptor associated with a particular memseg (if available). Note This function does not perform any locking, and is only safe to call from within memory-related callback functions. This returns an internal file descriptor. Performing any operations on this file descriptor is inherently dangerous, so it should be treated as read-only for all intents and purposes. Parameters ms A pointer to memseg for which to get file descriptor. Returns Valid file descriptor in case of success. -1 in case of error, with rte_errno set to the following values: * EINVAL - ms pointer was NULL or did not point to a valid memseg * ENODEV - ms fd is not available * ENOENT - ms is an unused segment * ENOTSUP - segment fd's are not supported int rte_memseg_get_fd_offset (const struct rte_memseg * ms, size_t * offset) Get offset into segment file descriptor associated with a particular memseg (if available). Note This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions. Parameters ms A pointer to memseg for which to get file descriptor. offset A pointer to offset value where the result will be stored. Returns Valid file descriptor in case of success. -1 in case of error, with rte_errno set to the following values: * EINVAL - ms pointer was NULL or did not point to a valid memseg * EINVAL - offset pointer was NULL * ENODEV - ms fd is not available * ENOENT - ms is an unused segment * ENOTSUP - segment fd's are not supported int rte_memseg_get_fd_offset_thread_unsafe (const struct rte_memseg * ms, size_t * offset) Get offset into segment file descriptor associated with a particular memseg (if available). Note This function does not perform any locking, and is only safe to call from within memory-related callback functions. Parameters ms A pointer to memseg for which to get file descriptor. offset A pointer to offset value where the result will be stored. Returns Valid file descriptor in case of success. -1 in case of error, with rte_errno set to the following values: * EINVAL - ms pointer was NULL or did not point to a valid memseg * EINVAL - offset pointer was NULL * ENODEV - ms fd is not available * ENOENT - ms is an unused segment * ENOTSUP - segment fd's are not supported int rte_extmem_register (void * va_addr, size_t len, rte_iova_t iova_addrs[], unsigned int n_pages, size_t page_sz) Register external memory chunk with DPDK. Note Using this API is mutually exclusive with rte_malloc family of API's. This API will not perform any DMA mapping. It is expected that user will do that themselves. Before accessing this memory in other processes, it needs to be at- tached in each of those processes by calling rte_extmem_attach in each other process. Parameters va_addr Start of virtual area to register. Must be aligned by page_sz. len Length of virtual area to register. Must be aligned by page_sz. iova_addrs Array of page IOVA addresses corresponding to each page in this memory area. Can be NULL, in which case page IOVA addresses will be set to RTE_BAD_IOVA. n_pages Number of elements in the iova_addrs array. Ignored if iova_ad- drs is NULL. page_sz Page size of the underlying memory Returns * 0 on success * -1 in case of error, with rte_errno set to one of the following: EIN- VAL - one of the parameters was invalid EEXIST - memory chunk is al- ready registered ENOSPC - no more space in internal config to store a new memory chunk int rte_extmem_unregister (void * va_addr, size_t len) Unregister external memory chunk with DPDK. Note Using this API is mutually exclusive with rte_malloc family of API's. This API will not perform any DMA unmapping. It is expected that user will do that themselves. Before calling this function, all other processes must call rte_extmem_detach to detach from the memory area. Parameters va_addr Start of virtual area to unregister len Length of virtual area to unregister Returns * 0 on success * -1 in case of error, with rte_errno set to one of the following: EIN- VAL - one of the parameters was invalid ENOENT - memory chunk was not found int rte_extmem_attach (void * va_addr, size_t len) Attach to external memory chunk registered in another process. Note Using this API is mutually exclusive with rte_malloc family of API's. This API will not perform any DMA mapping. It is expected that user will do that themselves. Parameters va_addr Start of virtual area to register len Length of virtual area to register Returns * 0 on success * -1 in case of error, with rte_errno set to one of the following: EIN- VAL - one of the parameters was invalid ENOENT - memory chunk was not found int rte_extmem_detach (void * va_addr, size_t len) Detach from external memory chunk registered in another process. Note Using this API is mutually exclusive with rte_malloc family of API's. This API will not perform any DMA unmapping. It is expected that user will do that themselves. Parameters va_addr Start of virtual area to unregister len Length of virtual area to unregister Returns * 0 on success * -1 in case of error, with rte_errno set to one of the following: EIN- VAL - one of the parameters was invalid ENOENT - memory chunk was not found void rte_dump_physmem_layout (FILE * f) Dump the physical memory layout to a file. Note This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions. Parameters f A pointer to a file for output uint64_t rte_eal_get_physmem_size (void) Get the total amount of available physical memory. Note This function read-locks the memory hotplug subsystem, and thus cannot be used within memory-related callback functions. Returns The total amount of available physical memory in bytes. unsigned rte_memory_get_nchannel (void) Get the number of memory channels. Returns The number of memory channels on the system. The value is 0 if unknown or not the same on all devices. unsigned rte_memory_get_nrank (void) Get the number of memory ranks. Returns The number of memory ranks on the system. The value is 0 if unknown or not the same on all devices. int rte_mem_check_dma_mask (uint8_t maskbits) Check if all currently allocated memory segments are compliant with sup- plied DMA address width. Parameters maskbits Address width to check against. int rte_mem_check_dma_mask_thread_unsafe (uint8_t maskbits) Check if all currently allocated memory segments are compliant with sup- plied DMA address width. This function will use rte_memseg_walk_thread_un- safe instead of rte_memseg_walk implying memory_hotplug_lock will not be acquired avoiding deadlock during memory initialization. This function is just for EAL core memory internal use. Drivers should use the previous rte_mem_check_dma_mask. Parameters maskbits Address width to check against. void rte_mem_set_dma_mask (uint8_t maskbits) Set dma mask to use once memory initialization is done. Previous functions rte_mem_check_dma_mask and rte_mem_check_dma_mask_thread_unsafe can not be used safely until memory has been initialized. int rte_eal_using_phys_addrs (void) Drivers based on uio will not load unless physical addresses are obtain- able. It is only possible to get physical addresses when running as a priv- ileged user. Returns 1 if the system is able to obtain physical addresses. 0 if using DMA addresses through an IOMMU. int rte_mem_event_callback_register (const char * name, rte_mem_event_call- back_t clb, void * arg) Function used to register callbacks for memory events. Note callbacks will happen while memory hotplug subsystem is write-locked, therefore some functions (e.g. rte_memseg_walk()) will cause a deadlock when called from within such callbacks. mem event callbacks not being supported is an expected error condition, so user code needs to handle this situation. In these cases, return value will be -1, and rte_errno will be set to ENOTSUP. Parameters name Name associated with specified callback to be added to the list. clb Callback function pointer. arg Argument to pass to the callback. Returns 0 on successful callback register -1 on unsuccessful callback register, with rte_errno value indicating reason for failure. int rte_mem_event_callback_unregister (const char * name, void * arg) Function used to unregister callbacks for memory events. Parameters name Name associated with specified callback to be removed from the list. arg Argument to look for among callbacks with specified callback name. Returns 0 on successful callback unregister -1 on unsuccessful callback unreg- ister, with rte_errno value indicating reason for failure. int rte_mem_alloc_validator_register (const char * name, rte_mem_alloc_val- idator_t clb, int socket_id, size_t limit) Register validator callback for memory allocations. Callbacks registered by this function will be called right before memory allocator is about to trigger allocation of more pages from the system if said allocation will bring total memory usage above specified limit on specified socket. User will be able to cancel pending allocation if callback returns -1. Note callbacks will happen while memory hotplug subsystem is write-locked, therefore some functions (e.g. rte_memseg_walk()) will cause a deadlock when called from within such callbacks. validator callbacks not being supported is an expected error condition, so user code needs to handle this situation. In these cases, return value will be -1, and rte_errno will be set to ENOTSUP. Parameters name Name associated with specified callback to be added to the list. clb Callback function pointer. socket_id Socket ID on which to watch for allocations. limit Limit above which to trigger callbacks. Returns 0 on successful callback register -1 on unsuccessful callback register, with rte_errno value indicating reason for failure. int rte_mem_alloc_validator_unregister (const char * name, int socket_id) Unregister validator callback for memory allocations. Parameters name Name associated with specified callback to be removed from the list. socket_id Socket ID on which to watch for allocations. Returns 0 on successful callback unregister -1 on unsuccessful callback unreg- ister, with rte_errno value indicating reason for failure. __rte_experimental void rte_memzero_explicit (void * dst, size_t sz) Warning EXPERIMENTAL: this API may change without prior notice. Fill memory with zero's (e.g. sensitive keys). Normally using memset() is fine, but in cases where clearing out local data before going out of scope is required, use rte_memzero_explicit() instead to prevent the compiler from optimizing away the zeroing operation. Parameters dst Target buffer. sz Number of bytes to fill. static __rte_experimental bool rte_memeq_timingsafe (const void * a, const void * b, size_t n) [inline], [static] Warning EXPERIMENTAL: this API may change without prior notice. Timing-safe memory equality comparison. This function compares two memory regions in constant time, making it re- sistant to timing side-channel attacks. The execution time depends only on the length parameter, not on the actual data values being compared. This is particularly important for cryptographic operations where timing differences could leak information about secret keys, passwords, or other sensitive data. Parameters a Pointer to the first memory region to compare. b Pointer to the second memory region to compare. n Number of bytes to compare. Returns true if the memory regions are identical, false if they differ. Definition at line 775 of file rte_memory.h. Author Generated automatically by Doxygen for DPDK from the source code. Version 25.11.0 Thu Aug 27 2026 rte_memory.h(3)
NAME | SYNOPSIS | Detailed Description | Macro Definition Documentation | Typedef Documentation | Enumeration Type Documentation | Function Documentation | Author
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