net/mlx5: fix unbind of incorrect hairpin queue
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Commit Message
Let's take an application with the following configuration:
- It uses 2 ports.
- Each port has 3 Rx queues and 3 Tx queues.
- On each port, Rx queues have a following purposes:
- Rx queue 0 - SW queue,
- Rx queue 1 - hairpin queue, bound to Tx queue on the same port,
- Rx queue 2 - hairpin queue, bound to Tx queue on another port.
- On each port, Tx queues have a following purposes:
- Tx queue 0 - SW queue,
- Tx queue 1 - hairpin queue, bound to Rx queue on the same port,
- Tx queue 2 - hairpin queue, bound to Rx queue on another port.
- Application configured all of the hairpin queues for manual binding.
After ports are configured and queues are set up,
if the application does the following API call sequence:
1. rte_eth_dev_start(port_id=0)
2. rte_eth_hairpin_bind(tx_port=0, rx_port=0)
3. rte_eth_hairpin_bind(tx_port=0, rx_port=1)
mlx5 PMD fails to modify SQ and logs this error:
mlx5_common: mlx5_devx_cmds.c:2079: mlx5_devx_cmd_modify_sq():
Failed to modify SQ using DevX
This error was caused by an incorrect unbind operation taken during
error handling inside call (3).
(3) fails, because port 1 (Rx side of the hairpin) was not started.
As a result of this failure, PMD goes into error handling, where all
previously bound hairpin queues are unbound.
This is incorrect, since this error handling procedure
in rte_eth_hairpin_bind() implementation assumes that
all hairpin queues are bound to the same rx_port, which is not the case.
The following sequence of function calls appears:
- rte_eth_hairpin_queue_peer_unbind(rx_port=**1**, rx_queue=1, 0),
- mlx5_hairpin_queue_peer_unbind(dev=**port 0**, tx_queue=1, 1).
Which violates the hairpin queue destroy flow, by unbinding Tx queue 1
on port 0, before unbinding Rx queue 1 on port 1.
This patch fixes that behavior, by filtering Tx queues on which error
handling is done to only affect:
- hairpin queues (it also reduces unnecessary debug log messages),
- hairpin queues connected to the rx_port which is currently processed.
Fixes: 37cd4501e873 ("net/mlx5: support two ports hairpin mode")
Cc: bingz@nvidia.com
Cc: stable@dpdk.org
Signed-off-by: Dariusz Sosnowski <dsosnowski@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
---
drivers/net/mlx5/mlx5_trigger.c | 5 +++++
1 file changed, 5 insertions(+)
Comments
Hi,
> -----Original Message-----
> From: Dariusz Sosnowski <dsosnowski@nvidia.com>
> Sent: Thursday, November 9, 2023 8:01 PM
> To: Matan Azrad <matan@nvidia.com>; Slava Ovsiienko
> <viacheslavo@nvidia.com>; Ori Kam <orika@nvidia.com>; Suanming Mou
> <suanmingm@nvidia.com>; Bing Zhao <bingz@nvidia.com>
> Cc: dev@dpdk.org; Raslan Darawsheh <rasland@nvidia.com>;
> stable@dpdk.org
> Subject: [PATCH] net/mlx5: fix unbind of incorrect hairpin queue
>
> Let's take an application with the following configuration:
>
> - It uses 2 ports.
> - Each port has 3 Rx queues and 3 Tx queues.
> - On each port, Rx queues have a following purposes:
> - Rx queue 0 - SW queue,
> - Rx queue 1 - hairpin queue, bound to Tx queue on the same port,
> - Rx queue 2 - hairpin queue, bound to Tx queue on another port.
> - On each port, Tx queues have a following purposes:
> - Tx queue 0 - SW queue,
> - Tx queue 1 - hairpin queue, bound to Rx queue on the same port,
> - Tx queue 2 - hairpin queue, bound to Rx queue on another port.
> - Application configured all of the hairpin queues for manual binding.
>
> After ports are configured and queues are set up, if the application does the
> following API call sequence:
>
> 1. rte_eth_dev_start(port_id=0)
> 2. rte_eth_hairpin_bind(tx_port=0, rx_port=0) 3.
> rte_eth_hairpin_bind(tx_port=0, rx_port=1)
>
> mlx5 PMD fails to modify SQ and logs this error:
>
> mlx5_common: mlx5_devx_cmds.c:2079: mlx5_devx_cmd_modify_sq():
> Failed to modify SQ using DevX
>
> This error was caused by an incorrect unbind operation taken during error
> handling inside call (3).
>
> (3) fails, because port 1 (Rx side of the hairpin) was not started.
> As a result of this failure, PMD goes into error handling, where all previously
> bound hairpin queues are unbound.
> This is incorrect, since this error handling procedure in rte_eth_hairpin_bind()
> implementation assumes that all hairpin queues are bound to the same
> rx_port, which is not the case.
> The following sequence of function calls appears:
>
> - rte_eth_hairpin_queue_peer_unbind(rx_port=**1**, rx_queue=1, 0),
> - mlx5_hairpin_queue_peer_unbind(dev=**port 0**, tx_queue=1, 1).
>
> Which violates the hairpin queue destroy flow, by unbinding Tx queue 1 on
> port 0, before unbinding Rx queue 1 on port 1.
>
> This patch fixes that behavior, by filtering Tx queues on which error handling is
> done to only affect:
>
> - hairpin queues (it also reduces unnecessary debug log messages),
> - hairpin queues connected to the rx_port which is currently processed.
>
> Fixes: 37cd4501e873 ("net/mlx5: support two ports hairpin mode")
> Cc: bingz@nvidia.com
> Cc: stable@dpdk.org
>
> Signed-off-by: Dariusz Sosnowski <dsosnowski@nvidia.com>
> Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> ---
Patch applied to next-net-mlx,
Kindest regards,
Raslan Darawsheh
@@ -845,6 +845,11 @@ mlx5_hairpin_bind_single_port(struct rte_eth_dev *dev, uint16_t rx_port)
txq_ctrl = mlx5_txq_get(dev, i);
if (txq_ctrl == NULL)
continue;
+ if (!txq_ctrl->is_hairpin ||
+ txq_ctrl->hairpin_conf.peers[0].port != rx_port) {
+ mlx5_txq_release(dev, i);
+ continue;
+ }
rx_queue = txq_ctrl->hairpin_conf.peers[0].queue;
rte_eth_hairpin_queue_peer_unbind(rx_port, rx_queue, 0);
mlx5_hairpin_queue_peer_unbind(dev, i, 1);