Re: [PATCH v3] hv_netvsc: Allocate rx indirection table size dynamically

[Simon Horman <simon.horman@corigine.com>]

On Thu, May 25, 2023 at 11:02:29PM -0700, Shradha Gupta wrote:
> Allocate the size of rx indirection table dynamically in netvsc
> from the value of size provided by OID_GEN_RECEIVE_SCALE_CAPABILITIES
> query instead of using a constant value of ITAB_NUM.
> 
> Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>

> @@ -1548,6 +1549,17 @@ struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
>  	if (ret || rsscap.num_recv_que < 2)
>  		goto out;
>  
> +	if (rsscap.num_indirect_tabent &&
> +	    rsscap.num_indirect_tabent <= ITAB_NUM_MAX)
> +		ndc->rx_table_sz = rsscap.num_indirect_tabent;
> +	else
> +		ndc->rx_table_sz = ITAB_NUM;
> +
> +	ndc->rx_table = kcalloc(ndc->rx_table_sz, sizeof(u16),
> +				GFP_KERNEL);

nit: the above could fit on a single line.

> +	if (!ndc->rx_table)

I think you need to set ret to an error value here,
as err_dev_remv will call return ERR_PTR(ret).

> +		goto err_dev_remv;
> +
>  	/* This guarantees that num_possible_rss_qs <= num_online_cpus */
>  	num_possible_rss_qs = min_t(u32, num_online_cpus(),
>  				    rsscap.num_recv_que);
> @@ -1558,7 +1570,7 @@ struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
>  	net_device->num_chn = min(net_device->max_chn, device_info->num_chn);
>  
>  	if (!netif_is_rxfh_configured(net)) {
> -		for (i = 0; i < ITAB_NUM; i++)
> +		for (i = 0; i < ndc->rx_table_sz; i++)
>  			ndc->rx_table[i] = ethtool_rxfh_indir_default(
>  						i, net_device->num_chn);
>  	}
> @@ -1596,11 +1608,18 @@ void rndis_filter_device_remove(struct hv_device *dev,
>  				struct netvsc_device *net_dev)
>  {
>  	struct rndis_device *rndis_dev = net_dev->extension;
> +	struct net_device *net = hv_get_drvdata(dev);
> +	struct net_device_context *ndc = netdev_priv(net);

nit: Please use reverse xmas tree order - longest line to shortest -
     for local variable declaration sin networking code.

	struct rndis_device *rndis_dev = net_dev->extension;
	struct net_device *net = hv_get_drvdata(dev);
	struct net_device_context *ndc;

	ndc = netdev_priv(net);

>  
>  	/* Halt and release the rndis device */
>  	rndis_filter_halt_device(net_dev, rndis_dev);
>  
>  	netvsc_device_remove(dev);
> +
> +	ndc->rx_table_sz = 0;
> +	kfree(ndc->rx_table);
> +	ndc->rx_table = NULL;
> +
>  }
>  
>  int rndis_filter_open(struct netvsc_device *nvdev)

-- 
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