[PATCH 6.1 022/280] hv_netvsc: Allocate rx indirection table size dynamically

Greg Kroah-Hartman
2026-02-04T15:04:20Z

From: Shradha Gupta <shradhagupta@linux.microsoft.com>

[ Upstream commit 4cab498f33f7adaa01ad15909c0f34a81e5a0b0a ]

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>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Tested-on: Ubuntu22 (azure VM, SKU size: Standard_F72s_v2)
Testcases:
1. ethtool -x eth0 output
2. LISA testcase:PERF-NETWORK-TCP-THROUGHPUT-MULTICONNECTION-NTTTCP-Synthetic
3. LISA testcase:PERF-NETWORK-TCP-THROUGHPUT-MULTICONNECTION-NTTTCP-SRIOV
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: d23564955811 ("net: hv_netvsc: reject RSS hash key programming without RX indirection table")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/hyperv/hyperv_net.h | 5 ++++-
drivers/net/hyperv/netvsc_drv.c | 10 ++++++----
drivers/net/hyperv/rndis_filter.c | 29 +++++++++++++++++++++++++----
3 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index ea9cb1ac4bbe1..97952229a7b77 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;
@@ -1045,7 +1046,9 @@ struct net_device_context {

u32 tx_table[VRSS_SEND_TAB_SIZE];

- u16 rx_table[ITAB_NUM];
+ u16 *rx_table;
+
+ u32 rx_table_sz;

/* Ethtool settings */
u8 duplex;
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 7433fe7699432..68dfe77a6bbfe 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1717,7 +1717,9 @@ 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,
@@ -1736,7 +1738,7 @@ 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];
}

@@ -1762,11 +1764,11 @@ 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];
}

diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index bb656ea097731..09144f0ec2aa4 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -21,6 +21,7 @@
#include <linux/rtnetlink.h>
#include <linux/ucs2_string.h>
#include <linux/string.h>
+#include <linux/slab.h>

#include "hyperv_net.h"
#include "netvsc_trace.h"
@@ -913,7 +914,7 @@ 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;
@@ -939,7 +940,7 @@ 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 +
@@ -947,7 +948,7 @@ 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 */
@@ -1534,6 +1535,18 @@ 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);
+ if (!ndc->rx_table) {
+ ret = -ENOMEM;
+ 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);
@@ -1544,7 +1557,7 @@ 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);
}
@@ -1582,11 +1595,19 @@ 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;
+
+ 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)
--
2.51.0