Struct IbvQueuePair 

pub struct IbvQueuePair {
    pub send_cq: usize,
    pub recv_cq: usize,
    pub dv_qp: usize,
    pub dv_send_cq: usize,
    pub dv_recv_cq: usize,
    /* private fields */
}

An RDMA Queue Pair (QP) for communication between two endpoints.

Encapsulates the send/receive queues, completion queues, and mlx5dv device-specific structures needed for RDMA communication.

Connection Lifecycle

1. Create with new() from context and protection domain pointers
2. Get connection info with get_qp_info()
3. Exchange connection info with remote peer
4. Connect to remote endpoint with connect()
5. Perform RDMA operations with put() or get()
6. Poll for completions with poll_completion()

Notes

• The qp field stores a pointer to rdmaxcel_qp_t (not ibv_qp). It is private; external callers reach it via Self::as_ptr.
• rdmaxcel_qp_t contains atomic counters and completion caches internally
• IbvQueuePair is single-owner: its Drop destroys the FFI QP, so the type is intentionally !Clone (and not sent across the wire).

Fields

send_cq: usize

recv_cq: usize

dv_qp: usize

dv_send_cq: usize

dv_recv_cq: usize

Implementations

impl IbvQueuePair

pub unsafe fn as_ptr(&self) -> *mut rdmaxcel_qp

Returns the underlying rdmaxcel_qp_t pointer for callers driving the device doorbell or building FFI parameter blocks directly.

Safety

The returned pointer is only valid for as long as the borrow of self lives. The caller must ensure all reads/writes through the pointer complete before this IbvQueuePair is dropped, since Drop calls rdmaxcel_qp_destroy on it.

pub fn new<I: IbvDomainImpl>( domain: &IbvDomain<I>, config: IbvConfig, ) -> Result<Self, Error>

Creates a new IbvQueuePair.

Initializes a new Queue Pair (QP) and associated Completion Queues (CQ) using the provided context and protection domain. The QP is created in the RESET state and must be transitioned via connect() before use.

Errors

Returns errors if CQ or QP creation fails.

pub fn get_qp_info(&mut self) -> Result<IbvQpInfo, Error>

Returns the connection info needed by a remote peer to connect to this QP.

pub fn state(&mut self) -> Result<u32, Error>

Returns the current state of the QP.

pub fn connect(&mut self, connection_info: &IbvQpInfo) -> Result<(), Error>

Transitions the QP through INIT -> RTR -> RTS to establish a connection.

Arguments

• connection_info - The remote connection info to connect to

pub fn recv( &mut self, lhandle: IbvBuffer, rhandle: IbvBuffer, ) -> Result<u64, Error>

pub fn put_with_recv( &mut self, lhandle: IbvBuffer, rhandle: IbvBuffer, ) -> Result<Vec<u64>, Error>

pub fn put( &mut self, lhandle: IbvBuffer, rhandle: IbvBuffer, ) -> Result<Vec<u64>, Error>

pub fn ring_doorbell(&mut self) -> Result<(), Error>

Rings the doorbell to execute all enqueued operations.

pub fn enqueue_put( &mut self, lhandle: IbvBuffer, rhandle: IbvBuffer, ) -> Result<Vec<u64>, Error>

Enqueues a put operation without ringing the doorbell.

pub fn enqueue_put_with_recv( &mut self, lhandle: IbvBuffer, rhandle: IbvBuffer, ) -> Result<Vec<u64>, Error>

Enqueues a put-with-receive operation without ringing the doorbell.

pub fn enqueue_get( &mut self, lhandle: IbvBuffer, rhandle: IbvBuffer, ) -> Result<Vec<u64>, Error>

Enqueues a get operation without ringing the doorbell.

pub fn get( &mut self, lhandle: IbvBuffer, rhandle: IbvBuffer, ) -> Result<Vec<u64>, Error>

pub fn poll_completion( &mut self, target: PollTarget, ) -> Result<Option<Result<IbvWc, WorkRequestError>>, PollCompletionError>

Polls target’s completion queue for a single work completion.

This is a thin wrapper over one ibv_poll_cq call. It does no per-WR bookkeeping: the caller owns matching each completion back to the work request it posted (by IbvWc::wr_id) and must keep polling until the queue drains so that no completion is lost.

Returns

• Ok(None) — the CQ is currently empty.
• Ok(Some(Ok(wc))) — a completion landed with success status.
• Ok(Some(Err(_))) — a completion landed with a non-success status; the WorkRequestError names the failed request.
• Err(_) — ibv_poll_cq itself failed; the QP should be treated as poisoned.

Trait Implementations

impl Debug for IbvQueuePair

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for IbvQueuePair

fn drop(&mut self)

Executes the destructor for this type.

impl IbvQueuePair for IbvQueuePair

unsafe fn new<I: IbvDomainImpl<QueuePair = Self>>( domain: &IbvDomain<I>, config: IbvConfig, ) -> Result<Self, Error>

Creates a queue pair against domain in the RESET state; Self::connect transitions it to RTS before use.

fn connect(&mut self, info: &IbvQpInfo) -> Result<(), Error>

Transitions the QP through INIT -> RTR -> RTS, connected to info.

fn get_qp_info(&mut self) -> Result<IbvQpInfo, Error>

Returns the local endpoint other peers need in order to connect to this QP.

fn state(&mut self) -> Result<u32, Error>

Returns the current ibv_qp_state of the QP.

fn put( &mut self, remote_dst: IbvBuffer, local_src: IbvBuffer, ) -> Result<Vec<u64>, Error>

Post an RDMA WRITE of local_src into remote_dst. The request may be chunked into multiple WRs. This method returns the list of WR ids that were posted.

fn get( &mut self, local_dst: IbvBuffer, remote_src: IbvBuffer, ) -> Result<Vec<u64>, Error>

Post an RDMA READ of remote_src into local_dst. The request may be chunked into multiple WRs. This method returns the list of WR ids that were posted.

fn poll_completion( &mut self, target: PollTarget, ) -> Result<Option<Result<IbvWc, WorkRequestError>>, PollCompletionError>

Poll target’s completion queue for a single work completion.