[PATCH v2 2/8] net/netvsc: fix race conditions on VF add/remove events

[Stephen Hemminger]

On Fri, 20 Feb 2026 18:45:21 -0800
longli at linux.microsoft.com wrote:

> +	rte_rwlock_read_lock(&hv->vf_lock);
> +	vf_dev = hn_get_vf_dev(hv);
> +	if (hv->vf_ctx.vf_vsc_switched && vf_dev &&
> +	    vf_dev->data->dev_started) {
> +		void *sub_q = vf_dev->data->tx_queues[queue_id];
> +
> +		nb_tx = (*vf_dev->tx_pkt_burst)
> +				(sub_q, tx_pkts, nb_pkts);
>  		rte_rwlock_read_unlock(&hv->vf_lock);
> +		return nb_tx;
>  	}
> +	rte_rwlock_read_unlock(&hv->vf_lock);

ok, but read locks not free. It does incur an additional cache miss
which may impact performance.

Might be better in future to have some form of lockless access here.