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

Simon Horman
2023-05-26T08:15:42Z

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)

--
pw-bot: cr