mlx5dv_devx_create_eq(3)

💅 mlx5dv_devx_create_eq(3) — mlx5 Programmer's Manual

okay so bestie, welcome to the mlx5 Programmer's Manual ✨ this page covers two icons: mlx5dv_devx_create_eq and mlx5dv_devx_destroy_eq. one makes an EQ object, one yeets it. that's the whole vibe, let's get into it 🫶

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🌸 NAME 🌸

• mlx5dv_devx_create_eq — Create an EQ object 💖
• mlx5dv_devx_destroy_eq — Destroy an EQ object 💀

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✨ SYNOPSIS ✨

#include <infiniband/mlx5dv.h>

struct mlx5dv_devx_eq *
mlx5dv_devx_create_eq(struct ibv_context *ibctx, const void *in, size_t inlen,
              void *out, size_t outlen);

int mlx5dv_devx_destroy_eq(struct mlx5dv_devx_eq *eq);

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🎀 DESCRIPTION 🎀

So you wanna Create / Destroy an EQ object, periodt. 💅

When you're creating one, you (the caller) are the main character here — you prepare the in/out mailboxes based on the device specification format. like, that's your job, no cap.

For the input mailbox, the caller needs to prepare all the fields except "eqc.log_page_size" and the pas list — those two get set by the driver, so don't touch, iykyk 🙈.

And the "eqc.intr" field? you should use that from the output of mlx5dv_devx_alloc_msi_vector(). literally, that's where it comes from. ⭐

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🦋 ARGUMENTS 🦋

• ibctx — the RDMA device context you're creating the action on. your canvas, your moment. 🎨
• in — a buffer holding the command's input data, provided in a device specification format.
• inlen — the size of the in buffer, in bytes.
• out — a buffer holding the command's output data, according to the device specification format.
• outlen — the size of the out buffer, in bytes.
• eq — the EQ object you wanna work on.

and here's the struct, look at her:

struct mlx5dv_devx_eq {
    void *vaddr;
};

• vaddr — the EQ VA that was allocated in the driver for. 🧚

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💜 NOTES 💜

⚠️ important bestie: mlx5dv_devx_query_eqn() will not support vectors which are used by mlx5dv_devx_create_eq(). so like, don't even try it. 💀

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🔥 RETURN VALUE 🔥

Upon success, mlx5dv_devx_create_eq will return a new struct mlx5dv_devx_eq. slay. 👑 On error, NULL will be returned and errno will be set. 😭

Upon success, mlx5dv_devx_destroy_eq will return 0. on error, errno will be returned.

🚨 If the error value is EREMOTEIO, outbox.status and outbox.syndrome will contain the command failure details. so check those, fr fr.

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🌈 SEE ALSO 🌈

• mlx5dv_devx_alloc_msi_vector(3)
• mlx5dv_devx_query_eqn(3)

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🌸 AUTHOR 🌸

Mark Zhang <markzhang@nvidia.com> — icon, legend, the moment. 🫶

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okay that's the whole page, you ate that 💅✨ this was mlx5, dated 2022-01-12, brought to you by the mlx5dv_devx_create_eq(3) girlies. go forth and create your EQs bestie 🎀🦋