[PATCH net] hv_netvsc: Fix unwanted rx_table reset

[PATCH net] hv_netvsc: Fix unwanted rx_table reset

[Haiyang Zhang]

In existing code, the receive indirection table, rx_table, is in
struct rndis_device, which will be reset when changing MTU, ringparam,
etc. User configured receive indirection table values will be lost.

To fix this, move rx_table to struct net_device_context, and check
netif_is_rxfh_configured(), so rx_table will be set to default only
if no user configured value.

Fixes: ff4a44199012 ("netvsc: allow get/set of RSS indirection table")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/hyperv/hyperv_net.h   |  3 ++-
 drivers/net/hyperv/netvsc_drv.c   |  4 ++--
 drivers/net/hyperv/rndis_filter.c | 10 +++++++---
 3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 9caa876..dc44819 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -169,7 +169,6 @@ struct rndis_device {
 
 	u8 hw_mac_adr[ETH_ALEN];
 	u8 rss_key[NETVSC_HASH_KEYLEN];
-	u16 rx_table[ITAB_NUM];
 };
 
 
@@ -940,6 +939,8 @@ struct net_device_context {
 
 	u32 tx_table[VRSS_SEND_TAB_SIZE];
 
+	u16 rx_table[ITAB_NUM];
+
 	/* Ethtool settings */
 	u8 duplex;
 	u32 speed;
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index eff8fef..68bf671 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1662,7 +1662,7 @@ 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++)
-			indir[i] = rndis_dev->rx_table[i];
+			indir[i] = ndc->rx_table[i];
 	}
 
 	if (key)
@@ -1692,7 +1692,7 @@ static int netvsc_set_rxfh(struct net_device *dev, const u32 *indir,
 				return -EINVAL;
 
 		for (i = 0; i < ITAB_NUM; i++)
-			rndis_dev->rx_table[i] = indir[i];
+			ndc->rx_table[i] = indir[i];
 	}
 
 	if (!key) {
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index 05bc5ec8..857c4be 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -773,6 +773,7 @@ static int rndis_set_rss_param_msg(struct rndis_device *rdev,
 				   const u8 *rss_key, u16 flag)
 {
 	struct net_device *ndev = rdev->ndev;
+	struct net_device_context *ndc = netdev_priv(ndev);
 	struct rndis_request *request;
 	struct rndis_set_request *set;
 	struct rndis_set_complete *set_complete;
@@ -812,7 +813,7 @@ 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++)
-		itab[i] = rdev->rx_table[i];
+		itab[i] = ndc->rx_table[i];
 
 	/* Set hask key values */
 	keyp = (u8 *)((unsigned long)rssp + rssp->hashkey_offset);
@@ -1312,6 +1313,7 @@ struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
 				      struct netvsc_device_info *device_info)
 {
 	struct net_device *net = hv_get_drvdata(dev);
+	struct net_device_context *ndc = netdev_priv(net);
 	struct netvsc_device *net_device;
 	struct rndis_device *rndis_device;
 	struct ndis_recv_scale_cap rsscap;
@@ -1398,9 +1400,11 @@ struct netvsc_device *rndis_filter_device_add(struct hv_device *dev,
 	/* We will use the given number of channels if available. */
 	net_device->num_chn = min(net_device->max_chn, device_info->num_chn);
 
-	for (i = 0; i < ITAB_NUM; i++)
-		rndis_device->rx_table[i] = ethtool_rxfh_indir_default(
+	if (!netif_is_rxfh_configured(net)) {
+		for (i = 0; i < ITAB_NUM; i++)
+			ndc->rx_table[i] = ethtool_rxfh_indir_default(
 						i, net_device->num_chn);
+	}
 
 	atomic_set(&net_device->open_chn, 1);
 	vmbus_set_sc_create_callback(dev->channel, netvsc_sc_open);
-- 
1.8.3.1

Re: [PATCH net] hv_netvsc: Fix unwanted rx_table reset

[David Miller]

From: Haiyang Zhang <haiyangz@microsoft.com>
Date: Thu, 19 Dec 2019 18:28:10 -0800

> In existing code, the receive indirection table, rx_table, is in
> struct rndis_device, which will be reset when changing MTU, ringparam,
> etc. User configured receive indirection table values will be lost.
> 
> To fix this, move rx_table to struct net_device_context, and check
> netif_is_rxfh_configured(), so rx_table will be set to default only
> if no user configured value.
> 
> Fixes: ff4a44199012 ("netvsc: allow get/set of RSS indirection table")
> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>

Applied.