Re: [PATCH] hv_netvsc: Allocate rx indirection table size dynamically
From: Steen Hegelund
Date: Wed May 24 2023 - 04:28:06 EST
Hi Shradha,
On Tue, 2023-05-23 at 22:57 -0700, Shradha Gupta wrote:
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> 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@xxxxxxxxxxxxxxxxxxx>
> ---
> drivers/net/hyperv/hyperv_net.h | 5 ++++-
> drivers/net/hyperv/netvsc_drv.c | 11 +++++++----
> drivers/net/hyperv/rndis_filter.c | 23 +++++++++++++++++++----
> 3 files changed, 30 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
> index dd5919ec408b..1dbdb65ca8f0 100644
> --- a/drivers/net/hyperv/hyperv_net.h
> +++ b/drivers/net/hyperv/hyperv_net.h
> @@ -74,6 +74,7 @@ struct ndis_recv_scale_cap { /*
> NDIS_RECEIVE_SCALE_CAPABILITIES */
> #define NDIS_RSS_HASH_SECRET_KEY_MAX_SIZE_REVISION_2 40
>
> #define ITAB_NUM 128
> +#define ITAB_NUM_MAX 256
>
> struct ndis_recv_scale_param { /* NDIS_RECEIVE_SCALE_PARAMETERS */
> struct ndis_obj_header hdr;
> @@ -1034,7 +1035,9 @@ struct net_device_context {
>
> u32 tx_table[VRSS_SEND_TAB_SIZE];
>
> - u16 rx_table[ITAB_NUM];
> + u16 *rx_table;
> +
> + int rx_table_sz;
>
> /* Ethtool settings */
> u8 duplex;
> diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
> index 0103ff914024..5b8a7d5f9a15 100644
> --- a/drivers/net/hyperv/netvsc_drv.c
> +++ b/drivers/net/hyperv/netvsc_drv.c
> @@ -1747,7 +1747,9 @@ static u32 netvsc_get_rxfh_key_size(struct net_device
> *dev)
>
> static u32 netvsc_rss_indir_size(struct net_device *dev)
> {
> - return ITAB_NUM;
> + struct net_device_context *ndc = netdev_priv(dev);
> +
> + return ndc->rx_table_sz;
> }
>
> static int netvsc_get_rxfh(struct net_device *dev, u32 *indir, u8 *key,
> @@ -1766,7 +1768,7 @@ static int netvsc_get_rxfh(struct net_device *dev, u32
> *indir, u8 *key,
>
> rndis_dev = ndev->extension;
> if (indir) {
> - for (i = 0; i < ITAB_NUM; i++)
> + for (i = 0; i < ndc->rx_table_sz; i++)
> indir[i] = ndc->rx_table[i];
> }
>
> @@ -1792,11 +1794,11 @@ static int netvsc_set_rxfh(struct net_device *dev,
> const u32 *indir,
>
> rndis_dev = ndev->extension;
> if (indir) {
> - for (i = 0; i < ITAB_NUM; i++)
> + for (i = 0; i < ndc->rx_table_sz; i++)
> if (indir[i] >= ndev->num_chn)
> return -EINVAL;
>
> - for (i = 0; i < ITAB_NUM; i++)
> + for (i = 0; i < ndc->rx_table_sz; i++)
> ndc->rx_table[i] = indir[i];
> }
>
> @@ -2638,6 +2640,7 @@ static void netvsc_remove(struct hv_device *dev)
>
> hv_set_drvdata(dev, NULL);
>
> + kfree(ndev_ctx->rx_table);
> free_percpu(ndev_ctx->vf_stats);
> free_netdev(net);
> }
> diff --git a/drivers/net/hyperv/rndis_filter.c
> b/drivers/net/hyperv/rndis_filter.c
> index eea777ec2541..af031e711cb2 100644
> --- a/drivers/net/hyperv/rndis_filter.c
> +++ b/drivers/net/hyperv/rndis_filter.c
> @@ -927,7 +927,7 @@ static int rndis_set_rss_param_msg(struct rndis_device
> *rdev,
> struct rndis_set_request *set;
> struct rndis_set_complete *set_complete;
> u32 extlen = sizeof(struct ndis_recv_scale_param) +
> - 4 * ITAB_NUM + NETVSC_HASH_KEYLEN;
> + 4 * ndc->rx_table_sz + NETVSC_HASH_KEYLEN;
> struct ndis_recv_scale_param *rssp;
> u32 *itab;
> u8 *keyp;
> @@ -953,7 +953,7 @@ static int rndis_set_rss_param_msg(struct rndis_device
> *rdev,
> rssp->hashinfo = NDIS_HASH_FUNC_TOEPLITZ | NDIS_HASH_IPV4 |
> NDIS_HASH_TCP_IPV4 | NDIS_HASH_IPV6 |
> NDIS_HASH_TCP_IPV6;
> - rssp->indirect_tabsize = 4*ITAB_NUM;
> + rssp->indirect_tabsize = 4 * ndc->rx_table_sz;
> rssp->indirect_taboffset = sizeof(struct ndis_recv_scale_param);
> rssp->hashkey_size = NETVSC_HASH_KEYLEN;
> rssp->hashkey_offset = rssp->indirect_taboffset +
> @@ -961,7 +961,7 @@ static int rndis_set_rss_param_msg(struct rndis_device
> *rdev,
>
> /* Set indirection table entries */
> itab = (u32 *)(rssp + 1);
> - for (i = 0; i < ITAB_NUM; i++)
> + for (i = 0; i < ndc->rx_table_sz; i++)
> itab[i] = ndc->rx_table[i];
>
> /* Set hask key values */
> @@ -1548,6 +1548,21 @@ 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 = kzalloc(sizeof(u16) * ndc->rx_table_sz,
> + GFP_KERNEL);
> + if (ndc->rx_table) {
> + netdev_err(net, "Error in allocating rx indirection table of
> size %d\n",
> + ndc->rx_table_sz);
> + goto out;
> + }
> +
You are now always allocating the rx_table in the rndis_filter_device_add()
function, but this function is called both from the netvsc_probe function
and the netvsc_attach function, but as far as I can see the rx_table only
gets freed in the remove function not in the netvsc_detach.
So if there is a chance that the attach/detach will be called more times
on a existing device you will have a leak.
> /* 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 +1573,7 @@ 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);
> }
> --
> 2.34.1
>
>
Best Regards
Steen