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rte_vhost.h(3) DPDK rte_vhost.h(3) NAME rte_vhost.h SYNOPSIS #include <stdbool.h> #include <stdint.h> #include <sys/eventfd.h> #include <rte_compat.h> #include <rte_memory.h> #include <rte_mempool.h> #include <linux/vhost.h> #include <linux/virtio_ring.h> #include <linux/virtio_net.h> Data Structures struct rte_vhost_mem_region struct rte_vhost_memory struct rte_vhost_user_extern_ops struct rte_vhost_device_ops struct rte_vhost_power_monitor_cond struct rte_vhost_stat struct rte_vhost_stat_name Macros #define VHOST_USER_PROTOCOL_F_MQ 0 #define VHOST_USER_F_PROTOCOL_FEATURES 30 #define RTE_VHOST_STATS_NAME_SIZE 64 Typedefs typedef enum rte_vhost_msg_result(* rte_vhost_msg_handle) (int vid, void *msg) Enumerations enum rte_vhost_msg_result Functions static __rte_always_inline uint64_t rte_vhost_va_from_guest_pa (struct rte_vhost_memory *mem, uint64_t gpa, uint64_t *len) void rte_vhost_log_write (int vid, uint64_t addr, uint64_t len) void rte_vhost_log_used_vring (int vid, uint16_t vring_idx, uint64_t offset, uint64_t len) __rte_experimental void rte_vhost_notify_guest (int vid, uint16_t queue_id) int rte_vhost_driver_register (const char *path, uint64_t flags) int rte_vhost_driver_attach_vdpa_device (const char *path, struct rte_vdpa_device *dev) int rte_vhost_driver_detach_vdpa_device (const char *path) struct rte_vdpa_device * rte_vhost_driver_get_vdpa_device (const char *path) int rte_vhost_driver_get_vdpa_dev_type (const char *path, uint32_t *type) int rte_vhost_driver_set_features (const char *path, uint64_t features) int rte_vhost_driver_enable_features (const char *path, uint64_t features) int rte_vhost_driver_disable_features (const char *path, uint64_t features) int rte_vhost_driver_get_features (const char *path, uint64_t *features) int rte_vhost_driver_set_protocol_features (const char *path, uint64_t protocol_features) int rte_vhost_driver_get_protocol_features (const char *path, uint64_t *protocol_features) int rte_vhost_driver_get_queue_num (const char *path, uint32_t *queue_num) int rte_vhost_driver_set_max_queue_num (const char *path, uint32_t max_queue_pairs) int rte_vhost_get_negotiated_features (int vid, uint64_t *features) int rte_vhost_get_negotiated_protocol_features (int vid, uint64_t *protocol_features) int rte_vhost_driver_start (const char *path) int rte_vhost_get_mtu (int vid, uint16_t *mtu) int rte_vhost_get_numa_node (int vid) uint16_t rte_vhost_get_vring_num (int vid) int rte_vhost_get_ifname (int vid, char *buf, size_t len) uint16_t rte_vhost_avail_entries (int vid, uint16_t queue_id) uint16_t rte_vhost_enqueue_burst (int vid, uint16_t queue_id, struct rte_mbuf **pkts, uint16_t count) uint16_t rte_vhost_dequeue_burst (int vid, uint16_t queue_id, struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count) int rte_vhost_get_mem_table (int vid, struct rte_vhost_memory **mem) int rte_vhost_get_vhost_vring (int vid, uint16_t vring_idx, struct rte_vhost_vring *vring) int rte_vhost_get_vhost_ring_inflight (int vid, uint16_t vring_idx, struct rte_vhost_ring_inflight *vring) int rte_vhost_set_inflight_desc_split (int vid, uint16_t vring_idx, uint16_t idx) int rte_vhost_set_inflight_desc_packed (int vid, uint16_t vring_idx, uint16_t head, uint16_t last, uint16_t *inflight_entry) int rte_vhost_set_last_inflight_io_split (int vid, uint16_t vring_idx, uint16_t idx) int rte_vhost_set_last_inflight_io_packed (int vid, uint16_t vring_idx, uint16_t head) int rte_vhost_clr_inflight_desc_split (int vid, uint16_t vring_idx, uint16_t last_used_idx, uint16_t idx) int rte_vhost_clr_inflight_desc_packed (int vid, uint16_t vring_idx, uint16_t head) int rte_vhost_vring_call (int vid, uint16_t vring_idx) int rte_vhost_vring_call_nonblock (int vid, uint16_t vring_idx) uint32_t rte_vhost_rx_queue_count (int vid, uint16_t qid) int rte_vhost_get_monitor_addr (int vid, uint16_t queue_id, struct rte_vhost_power_monitor_cond *pmc) int rte_vhost_get_log_base (int vid, uint64_t *log_base, uint64_t *log_size) int rte_vhost_get_vring_base (int vid, uint16_t queue_id, uint16_t *last_avail_idx, uint16_t *last_used_idx) int rte_vhost_get_vring_base_from_inflight (int vid, uint16_t queue_id, uint16_t *last_avail_idx, uint16_t *last_used_idx) int rte_vhost_set_vring_base (int vid, uint16_t queue_id, uint16_t last_avail_idx, uint16_t last_used_idx) int rte_vhost_extern_callback_register (int vid, struct rte_vhost_user_extern_ops const *const ops, void *ctx) struct rte_vdpa_device * rte_vhost_get_vdpa_device (int vid) int rte_vhost_backend_config_change (int vid, bool need_reply) int rte_vhost_vring_stats_get_names (int vid, uint16_t queue_id, struct rte_vhost_stat_name *name, unsigned int size) int rte_vhost_vring_stats_get (int vid, uint16_t queue_id, struct rte_vhost_stat *stats, unsigned int n) int rte_vhost_vring_stats_reset (int vid, uint16_t queue_id) Detailed Description Interface to vhost-user Definition in file rte_vhost.h. Macro Definition Documentation #define VHOST_USER_PROTOCOL_F_MQ 0 Protocol features. Definition at line 65 of file rte_vhost.h. #define VHOST_USER_F_PROTOCOL_FEATURES 30 Indicate whether protocol features negotiation is supported. Definition at line 118 of file rte_vhost.h. #define RTE_VHOST_STATS_NAME_SIZE 64 Maximum name length for the statistics counters Definition at line 337 of file rte_vhost.h. Typedef Documentation typedef enum rte_vhost_msg_result(* rte_vhost_msg_handle) (int vid, void *msg) Function prototype for the vhost backend to handle specific vhost user messages. Parameters vid vhost device id msg Message pointer. Returns RTE_VHOST_MSG_RESULT_OK on success, RTE_VHOST_MSG_RESULT_REPLY on success with reply, RTE_VHOST_MSG_RESULT_ERR on failure, RTE_VHOST_MSG_RESULT_NOT_HANDLED if message was not handled. Definition at line 1 of file rte_vhost.h. Enumeration Type Documentation enum rte_vhost_msg_result Possible results of the vhost user message handling callbacks Definition at line 237 of file rte_vhost.h. Function Documentation static __rte_always_inline uint64_t rte_vhost_va_from_guest_pa (struct rte_vhost_memory * mem, uint64_t gpa, uint64_t * len) [static] Convert guest physical address to host virtual address Parameters mem the guest memory regions gpa the guest physical address for querying len the size of the requested area to map, updated with actual size mapped Returns the host virtual address on success, 0 on failure Definition at line 375 of file rte_vhost.h. void rte_vhost_log_write (int vid, uint64_t addr, uint64_t len) Log the memory write start with given address. This function only need be invoked when the live migration starts. Therefore, we won't need call it at all in the most of time. For making the performance impact be minimum, it's suggested to do a check before calling it: if (unlikely(RTE_VHOST_NEED_LOG(features))) rte_vhost_log_write(vid, addr, len); Parameters vid vhost device ID addr the starting address for write (in guest physical address space) len the length to write void rte_vhost_log_used_vring (int vid, uint16_t vring_idx, uint64_t offset, uint64_t len) Log the used ring update start at given offset. Same as rte_vhost_log_write, it's suggested to do a check before calling it: if (unlikely(RTE_VHOST_NEED_LOG(features))) rte_vhost_log_used_vring(vid, vring_idx, offset, len); Parameters vid vhost device ID vring_idx the vring index offset the offset inside the used ring len the length to write __rte_experimental void rte_vhost_notify_guest (int vid, uint16_t queue_id) Warning EXPERIMENTAL: this API may change, or be removed, without prior notice. Inject the offloaded interrupt into the vhost device's queue. See also guest_notify vhost device operation Parameters vid vhost device ID queue_id virtio queue index int rte_vhost_driver_register (const char * path, uint64_t flags) Register vhost driver. path could be different for multiple instance support. int rte_vhost_driver_attach_vdpa_device (const char * path, struct rte_vdpa_device * dev) Set the vdpa device id, enforce single connection per socket Parameters path The vhost-user socket file path dev vDPA device pointer Returns 0 on success, -1 on failure int rte_vhost_driver_detach_vdpa_device (const char * path) Unset the vdpa device id Parameters path The vhost-user socket file path Returns 0 on success, -1 on failure struct rte_vdpa_device * rte_vhost_driver_get_vdpa_device (const char * path) Get the device id Parameters path The vhost-user socket file path Returns vDPA device pointer, NULL on failure int rte_vhost_driver_get_vdpa_dev_type (const char * path, uint32_t * type) Get the device type of the vdpa device. Parameters path The vhost-user socket file path type the device type of the vdpa device Returns 0 on success, -1 on failure int rte_vhost_driver_set_features (const char * path, uint64_t features) Set the feature bits the vhost-user driver supports. Parameters path The vhost-user socket file path features Supported features Returns 0 on success, -1 on failure int rte_vhost_driver_enable_features (const char * path, uint64_t features) Enable vhost-user driver features. Note that • the param features should be a subset of the feature bits provided by rte_vhost_driver_set_features(). • it must be invoked before vhost-user negotiation starts. Parameters path The vhost-user socket file path features Features to enable Returns 0 on success, -1 on failure int rte_vhost_driver_disable_features (const char * path, uint64_t features) Disable vhost-user driver features. The two notes at rte_vhost_driver_enable_features() also apply here. Parameters path The vhost-user socket file path features Features to disable Returns 0 on success, -1 on failure int rte_vhost_driver_get_features (const char * path, uint64_t * features) Get the feature bits before feature negotiation. Parameters path The vhost-user socket file path features A pointer to store the queried feature bits Returns 0 on success, -1 on failure int rte_vhost_driver_set_protocol_features (const char * path, uint64_t protocol_features) Set the protocol feature bits before feature negotiation. Parameters path The vhost-user socket file path protocol_features Supported protocol features Returns 0 on success, -1 on failure int rte_vhost_driver_get_protocol_features (const char * path, uint64_t * protocol_features) Get the protocol feature bits before feature negotiation. Parameters path The vhost-user socket file path protocol_features A pointer to store the queried protocol feature bits Returns 0 on success, -1 on failure int rte_vhost_driver_get_queue_num (const char * path, uint32_t * queue_num) Get the queue number bits before feature negotiation. Parameters path The vhost-user socket file path queue_num A pointer to store the queried queue number bits Returns 0 on success, -1 on failure int rte_vhost_driver_set_max_queue_num (const char * path, uint32_t max_queue_pairs) Set the maximum number of queue pairs supported by the device. The value set is ignored for Vhost-user backends. It is only taken into account with VDUSE backends. Parameters path The vhost-user socket file path max_queue_pairs The maximum number of queue pairs Returns 0 on success, -1 on failure int rte_vhost_get_negotiated_features (int vid, uint64_t * features) Get the feature bits after negotiation Parameters vid Vhost device ID features A pointer to store the queried feature bits Returns 0 on success, -1 on failure int rte_vhost_get_negotiated_protocol_features (int vid, uint64_t * protocol_features) Get the protocol feature bits after negotiation Parameters vid Vhost device ID protocol_features A pointer to store the queried protocol feature bits Returns 0 on success, -1 on failure int rte_vhost_driver_start (const char * path) Start the vhost-user driver. This function triggers the vhost-user negotiation. Parameters path The vhost-user socket file path Returns 0 on success, -1 on failure int rte_vhost_get_mtu (int vid, uint16_t * mtu) Get the MTU value of the device if set in QEMU. Parameters vid virtio-net device ID mtu The variable to store the MTU value Returns 0: success -EAGAIN: device not yet started -ENOTSUP: device does not support MTU feature int rte_vhost_get_numa_node (int vid) Get the numa node from which the virtio net device's memory is allocated. Parameters vid vhost device ID Returns The numa node, -1 on failure uint16_t rte_vhost_get_vring_num (int vid) Get the number of vrings the device supports. Parameters vid vhost device ID Returns The number of vrings, 0 on failure int rte_vhost_get_ifname (int vid, char * buf, size_t len) Get the virtio net device's ifname, which is the vhost-user socket file path. Parameters vid vhost device ID buf The buffer to stored the queried ifname len The length of buf Returns 0 on success, -1 on failure uint16_t rte_vhost_avail_entries (int vid, uint16_t queue_id) Get how many avail entries are left in the queue Parameters vid vhost device ID queue_id virtio queue index Returns num of avail entries left uint16_t rte_vhost_enqueue_burst (int vid, uint16_t queue_id, struct rte_mbuf ** pkts, uint16_t count) This function adds buffers to the virtio devices RX virtqueue. Buffers can be received from the physical port or from another virtual device. A packet count is returned to indicate the number of packets that were successfully added to the RX queue. Parameters vid vhost device ID queue_id virtio queue index in mq case pkts array to contain packets to be enqueued count packets num to be enqueued Returns num of packets enqueued uint16_t rte_vhost_dequeue_burst (int vid, uint16_t queue_id, struct rte_mempool * mbuf_pool, struct rte_mbuf ** pkts, uint16_t count) This function gets guest buffers from the virtio device TX virtqueue, construct host mbufs, copies guest buffer content to host mbufs and store them in pkts to be processed. Parameters vid vhost device ID queue_id virtio queue index in mq case mbuf_pool mbuf_pool where host mbuf is allocated. pkts array to contain packets to be dequeued count packets num to be dequeued Returns num of packets dequeued int rte_vhost_get_mem_table (int vid, struct rte_vhost_memory ** mem) Get guest mem table: a list of memory regions. An rte_vhost_vhost_memory object will be allocated internally, to hold the guest memory regions. Application should free it at destroy_device() callback. Parameters vid vhost device ID mem To store the returned mem regions Returns 0 on success, -1 on failure int rte_vhost_get_vhost_vring (int vid, uint16_t vring_idx, struct rte_vhost_vring * vring) Get guest vring info, including the vring address, vring size, etc. Parameters vid vhost device ID vring_idx vring index vring the structure to hold the requested vring info Returns 0 on success, -1 on failure int rte_vhost_get_vhost_ring_inflight (int vid, uint16_t vring_idx, struct rte_vhost_ring_inflight * vring) Get guest inflight vring info, including inflight ring and resubmit list. Parameters vid vhost device ID vring_idx vring index vring the structure to hold the requested inflight vring info Returns 0 on success, -1 on failure int rte_vhost_set_inflight_desc_split (int vid, uint16_t vring_idx, uint16_t idx) Set split inflight descriptor. This function save descriptors that has been consumed in available ring Parameters vid vhost device ID vring_idx vring index idx inflight entry index Returns 0 on success, -1 on failure int rte_vhost_set_inflight_desc_packed (int vid, uint16_t vring_idx, uint16_t head, uint16_t last, uint16_t * inflight_entry) Set packed inflight descriptor and get corresponding inflight entry This function save descriptors that has been consumed Parameters vid vhost device ID vring_idx vring index head head of descriptors last last of descriptors inflight_entry corresponding inflight entry Returns 0 on success, -1 on failure int rte_vhost_set_last_inflight_io_split (int vid, uint16_t vring_idx, uint16_t idx) Save the head of list that the last batch of used descriptors. Parameters vid vhost device ID vring_idx vring index idx descriptor entry index Returns 0 on success, -1 on failure int rte_vhost_set_last_inflight_io_packed (int vid, uint16_t vring_idx, uint16_t head) Update the inflight free_head, used_idx and used_wrap_counter. This function will update status first before updating descriptors to used Parameters vid vhost device ID vring_idx vring index head head of descriptors Returns 0 on success, -1 on failure int rte_vhost_clr_inflight_desc_split (int vid, uint16_t vring_idx, uint16_t last_used_idx, uint16_t idx) Clear the split inflight status. Parameters vid vhost device ID vring_idx vring index last_used_idx last used idx of used ring idx inflight entry index Returns 0 on success, -1 on failure int rte_vhost_clr_inflight_desc_packed (int vid, uint16_t vring_idx, uint16_t head) Clear the packed inflight status. Parameters vid vhost device ID vring_idx vring index head inflight entry index Returns 0 on success, -1 on failure int rte_vhost_vring_call (int vid, uint16_t vring_idx) Notify the guest that used descriptors have been added to the vring. This function acts as a memory barrier. Parameters vid vhost device ID vring_idx vring index Returns 0 on success, -1 on failure int rte_vhost_vring_call_nonblock (int vid, uint16_t vring_idx) Notify the guest that used descriptors have been added to the vring. This function acts as a memory barrier. This function will return -EAGAIN when vq's access lock is held by other thread, user should try again later. Parameters vid vhost device ID vring_idx vring index Returns 0 on success, -1 on failure, -EAGAIN for another retry uint32_t rte_vhost_rx_queue_count (int vid, uint16_t qid) Get vhost RX queue avail count. Parameters vid vhost device ID qid virtio queue index in mq case Returns num of desc available int rte_vhost_get_monitor_addr (int vid, uint16_t queue_id, struct rte_vhost_power_monitor_cond * pmc) Get power monitor address of the vhost device Parameters vid vhost device ID queue_id vhost queue ID pmc power monitor condition Returns 0 on success, -1 on failure int rte_vhost_get_log_base (int vid, uint64_t * log_base, uint64_t * log_size) Get log base and log size of the vhost device Parameters vid vhost device ID log_base vhost log base log_size vhost log size Returns 0 on success, -1 on failure int rte_vhost_get_vring_base (int vid, uint16_t queue_id, uint16_t * last_avail_idx, uint16_t * last_used_idx) Get last_avail/used_idx of the vhost virtqueue Parameters vid vhost device ID queue_id vhost queue index last_avail_idx vhost last_avail_idx to get last_used_idx vhost last_used_idx to get Returns 0 on success, -1 on failure int rte_vhost_get_vring_base_from_inflight (int vid, uint16_t queue_id, uint16_t * last_avail_idx, uint16_t * last_used_idx) Get last_avail/last_used of the vhost virtqueue This function is designed for the reconnection and it's specific for the packed ring as we can get the two parameters from the inflight queueregion Parameters vid vhost device ID queue_id vhost queue index last_avail_idx vhost last_avail_idx to get last_used_idx vhost last_used_idx to get Returns 0 on success, -1 on failure int rte_vhost_set_vring_base (int vid, uint16_t queue_id, uint16_t last_avail_idx, uint16_t last_used_idx) Set last_avail/used_idx of the vhost virtqueue Parameters vid vhost device ID queue_id vhost queue index last_avail_idx last_avail_idx to set last_used_idx last_used_idx to set Returns 0 on success, -1 on failure int rte_vhost_extern_callback_register (int vid, struct rte_vhost_user_extern_ops const *const ops, void * ctx) Register external message handling callbacks Parameters vid vhost device ID ops virtio external callbacks to register ctx additional context passed to the callbacks Returns 0 on success, -1 on failure struct rte_vdpa_device * rte_vhost_get_vdpa_device (int vid) Get vdpa device id for vhost device. Parameters vid vhost device id Returns vDPA device pointer on success, NULL on failure int rte_vhost_backend_config_change (int vid, bool need_reply) Notify the guest that should get virtio configuration space from backend. Parameters vid vhost device ID need_reply wait for the frontend response the status of this operation Returns 0 on success, < 0 on failure int rte_vhost_vring_stats_get_names (int vid, uint16_t queue_id, struct rte_vhost_stat_name * name, unsigned int size) Retrieve names of statistics of a Vhost virtqueue. There is an assumption that 'stat_names' and 'stats' arrays are matched by array index: stats_names[i].name => stats[i].value Parameters vid vhost device ID queue_id vhost queue index name array of at least size elements to be filled. If set to NULL, the function returns the required number of elements. size The number of elements in stats_names array. Returns • Success if greater than 0 and lower or equal to size. The return value indicates the number of elements filled in the names array. • Failure if greater than size. The return value indicates the number of elements the names array that should be given to succeed. • Failure if lower than 0. The device ID or queue ID is invalid or • statistics collection is not enabled. int rte_vhost_vring_stats_get (int vid, uint16_t queue_id, struct rte_vhost_stat * stats, unsigned int n) Retrieve statistics of a Vhost virtqueue. There is an assumption that 'stat_names' and 'stats' arrays are matched by array index: stats_names[i].name => stats[i].value Parameters vid vhost device ID queue_id vhost queue index stats A pointer to a table of structure of type rte_vhost_stat to be filled with virtqueue statistics ids and values. n The number of elements in stats array. Returns • Success if greater than 0 and lower or equal to n. The return value indicates the number of elements filled in the stats array. • Failure if greater than n. The return value indicates the number of elements the stats array that should be given to succeed. • Failure if lower than 0. The device ID or queue ID is invalid, or statistics collection is not enabled. int rte_vhost_vring_stats_reset (int vid, uint16_t queue_id) Reset statistics of a Vhost virtqueue. Parameters vid vhost device ID queue_id vhost queue index Returns • Success if 0. Statistics have been reset. • Failure if lower than 0. The device ID or queue ID is invalid, or statistics collection is not enabled. Author Generated automatically by Doxygen for DPDK from the source code. Version 25.11.0 Thu Jun 11 2026 rte_vhost.h(3)
NAME | SYNOPSIS | Detailed Description | Macro Definition Documentation | Typedef Documentation | Enumeration Type Documentation | Function Documentation | Author
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