mlx5dv_dev...msi_vector(3)

💖 NAME 💖

okay so bestie, this is the mlx5dv_dev...msi_vector(3) page from the mlx5 Programmer’s Manual, and it’s giving two functions with main character energy:

• mlx5dv_devx_alloc_msi_vector — allocate an msi vector to be used for creating an EQ.
• mlx5dv_devx_free_msi_vector — release an msi vector.

periodt. 💅

---

📎 SYNOPSIS 📎

#include <infiniband/mlx5dv.h>

struct mlx5dv_devx_msi_vector *
mlx5dv_devx_alloc_msi_vector(struct ibv_context *ibctx);

int mlx5dv_devx_free_msi_vector(struct mlx5dv_devx_msi_vector *msi);

---

✨ DESCRIPTION ✨

So basically: allocate or free an msi vector to be used for creating an EQ. 💖

The allocate API exposes an mlx5dv_devx_msi_vector object, which includes an msi vector and a fd. The vector can be used as the eqc.intr field when creating an EQ, while the fd (created as non-blocking) can be polled to see once there is some data on that EQ. iconic, honestly. 🦋

---

🎀 ARGUMENTS 🎀

• ibctx — RDMA device context to create the action on.
• msi — the msi vector object to work on.

💜 msi_vector 💜

struct mlx5dv_devx_msi_vector {
    int vector;
    int fd;
};

• vector — the vector to be used when creating the EQ over the device specification.
• fd — the FD that will be used for polling.

---

🌈 RETURN VALUE 🌈

Upon success, mlx5dv_devx_alloc_msi_vector will return a new struct mlx5dv_devx_msi_vector; on error, NULL will be returned and errno will be set. slay when it works, 😭 when it doesn’t.

Upon success, mlx5dv_devx_free_msi_vector will return 0; on error, errno will be returned.

---

👑 AUTHOR 👑

Mark Zhang <markzhang@nvidia.com>

---

xoxo, from the mlx5 source/version and the 2022-01-12 date 💖🫶✨