[PATCH v22.11] vhost: fix missing spinlock unlock

[Xueming(Steven) Li]

Thanks Maxime!

Hailin, could you please confirm if it fixes https://bugs.dpdk.org/show_bug.cgi?id=1338?

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin at redhat.com>
> Sent: 1/11/2024 18:52
> To: stable at dpdk.org; Xueming(Steven) Li <xuemingl at nvidia.com>;
> ktraynor at redhat.com; dmarchan at redhat.com
> Cc: Maxime Coquelin <maxime.coquelin at redhat.com>
> Subject: [PATCH v22.11] vhost: fix missing spinlock unlock
> 
> Two regressions were introduced when backporting below
> patch:
> b4c4e5675c85 ("vhost: fix missing lock protection in power monitor API")
> 
> First, rte_vhost_get_monitor_addr did not release the lock in the success case.
> Then, rte_rwlock_read_lock() was converted to rte_spinlock_trylock() instead of
> rte_spinlock_lock().
> 
> This patch addresses both of these issues.
> 
> Fixes: a07736eb68da ("vhost: fix missing lock protection in power monitor API")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
> ---
>  lib/vhost/vhost.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c index 40ac350e21..9e28198528
> 100644
> --- a/lib/vhost/vhost.c
> +++ b/lib/vhost/vhost.c
> @@ -2060,6 +2060,7 @@ rte_vhost_get_monitor_addr(int vid, uint16_t
> queue_id,  {
>  	struct virtio_net *dev = get_device(vid);
>  	struct vhost_virtqueue *vq;
> +	int ret = 0;
> 
>  	if (dev == NULL)
>  		return -1;
> @@ -2070,11 +2071,12 @@ rte_vhost_get_monitor_addr(int vid, uint16_t
> queue_id,
>  	if (vq == NULL)
>  		return -1;
> 
> -	if (!rte_spinlock_trylock(&vq->access_lock))
> -		return -1;
> +	rte_spinlock_lock(&vq->access_lock);
> 
> -	if (unlikely(!vq->access_ok))
> +	if (unlikely(!vq->access_ok)) {
> +		ret = -1;
>  		goto out_unlock;
> +	}
> 
>  	if (vq_is_packed(dev)) {
>  		struct vring_packed_desc *desc;
> @@ -2095,12 +2097,10 @@ rte_vhost_get_monitor_addr(int vid, uint16_t
> queue_id,
>  		pmc->match = 0;
>  	}
> 
> -	return 0;
> -
>  out_unlock:
>  	rte_spinlock_unlock(&vq->access_lock);
> 
> -	return -1;
> +	return ret;
>  }
> 
> 
> --
> 2.43.0