net/vhost: add flag to control wait queuing
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Commit Message
update_queuing_status prevents PMD queue operations from affecting
the data plane by waiting for rx/tx_pkt_burst to stops accessing the
vhost device.
In fact, it is only necessary to wait when destroy/stop the device,
new/start device and vring_state_changed cases do not need.
Since vring is locked when vring state changes, unconditional
waiting may also cause deadlocks.
To avoid deadlocks and unnecessary waiting, this patch adds a flag to
control whether waiting is required.
Fixes: 9dc6bb0682 (net/vhost: fix access to freed memory)
Fixes: 1ce3c7fe14 (net/vhost: emulate device start/stop behavior)
Cc: stable@dpdk.org
Signed-off-by: Yuan Wang <yuanx.wang@intel.com>
---
drivers/net/vhost/rte_eth_vhost.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
Comments
> -----Original Message-----
> From: Yuan Wang <yuanx.wang@intel.com>
> Sent: Wednesday, June 1, 2022 10:26 PM
> To: maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>;
> dev@dpdk.org
> Cc: Hu, Jiayu <jiayu.hu@intel.com>; He, Xingguang
> <xingguang.he@intel.com>; Wang, YuanX <yuanx.wang@intel.com>;
> stable@dpdk.org
> Subject: [PATCH] net/vhost: add flag to control wait queuing
>
> update_queuing_status prevents PMD queue operations from affecting the
> data plane by waiting for rx/tx_pkt_burst to stops accessing the vhost device.
> In fact, it is only necessary to wait when destroy/stop the device, new/start
> device and vring_state_changed cases do not need.
>
> Since vring is locked when vring state changes, unconditional waiting may
> also cause deadlocks.
>
> To avoid deadlocks and unnecessary waiting, this patch adds a flag to control
> whether waiting is required.
>
> Fixes: 9dc6bb0682 (net/vhost: fix access to freed memory)
> Fixes: 1ce3c7fe14 (net/vhost: emulate device start/stop behavior)
> Cc: stable@dpdk.org
>
> Signed-off-by: Yuan Wang <yuanx.wang@intel.com>
> ---
Tested-by: Wei Ling <weix.ling@intel.com>
@@ -716,7 +716,7 @@ eth_vhost_install_intr(struct rte_eth_dev *dev)
}
static void
-update_queuing_status(struct rte_eth_dev *dev)
+update_queuing_status(struct rte_eth_dev *dev, bool wait_queuing)
{
struct pmd_internal *internal = dev->data->dev_private;
struct vhost_queue *vq;
@@ -742,7 +742,7 @@ update_queuing_status(struct rte_eth_dev *dev)
rte_atomic32_set(&vq->allow_queuing, 1);
else
rte_atomic32_set(&vq->allow_queuing, 0);
- while (rte_atomic32_read(&vq->while_queuing))
+ while (wait_queuing && rte_atomic32_read(&vq->while_queuing))
rte_pause();
}
@@ -754,7 +754,7 @@ update_queuing_status(struct rte_eth_dev *dev)
rte_atomic32_set(&vq->allow_queuing, 1);
else
rte_atomic32_set(&vq->allow_queuing, 0);
- while (rte_atomic32_read(&vq->while_queuing))
+ while (wait_queuing && rte_atomic32_read(&vq->while_queuing))
rte_pause();
}
}
@@ -836,7 +836,7 @@ new_device(int vid)
eth_dev->data->dev_link.link_status = RTE_ETH_LINK_UP;
rte_atomic32_set(&internal->dev_attached, 1);
- update_queuing_status(eth_dev);
+ update_queuing_status(eth_dev, false);
VHOST_LOG(INFO, "Vhost device %d created\n", vid);
@@ -866,7 +866,7 @@ destroy_device(int vid)
internal = eth_dev->data->dev_private;
rte_atomic32_set(&internal->dev_attached, 0);
- update_queuing_status(eth_dev);
+ update_queuing_status(eth_dev, true);
eth_dev->data->dev_link.link_status = RTE_ETH_LINK_DOWN;
@@ -976,7 +976,7 @@ vring_state_changed(int vid, uint16_t vring, int enable)
state->max_vring = RTE_MAX(vring, state->max_vring);
rte_spinlock_unlock(&state->lock);
- update_queuing_status(eth_dev);
+ update_queuing_status(eth_dev, false);
VHOST_LOG(INFO, "vring%u is %s\n",
vring, enable ? "enabled" : "disabled");
@@ -1163,7 +1163,7 @@ eth_dev_start(struct rte_eth_dev *eth_dev)
}
rte_atomic32_set(&internal->started, 1);
- update_queuing_status(eth_dev);
+ update_queuing_status(eth_dev, false);
return 0;
}
@@ -1175,7 +1175,7 @@ eth_dev_stop(struct rte_eth_dev *dev)
dev->data->dev_started = 0;
rte_atomic32_set(&internal->started, 0);
- update_queuing_status(dev);
+ update_queuing_status(dev, true);
return 0;
}