netvsc: add ethtool ops to get/set RSS key

For some cases it is useful to be able to change RSS key value.
For example, replacing RSS key with a symmetric hash.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/hyperv/hyperv_net.h

@@ -156,6 +156,8 @@ enum rndis_device_state {
 	RNDIS_DEV_DATAINITIALIZED,
 };
 
+#define NETVSC_HASH_KEYLEN 40
+
 struct rndis_device {
 	struct net_device *ndev;
 
@@ -166,7 +168,8 @@ struct rndis_device {
 	spinlock_t request_lock;
 	struct list_head req_list;
 
-	unsigned char hw_mac_adr[ETH_ALEN];
+	u8 hw_mac_adr[ETH_ALEN];
+	u8 rss_key[NETVSC_HASH_KEYLEN];
 };
 
 
@@ -194,6 +197,8 @@ int rndis_filter_close(struct netvsc_device *nvdev);
 int rndis_filter_device_add(struct hv_device *dev,
 			void *additional_info);
 void rndis_filter_device_remove(struct hv_device *dev);
+int rndis_filter_set_rss_param(struct rndis_device *rdev,
+			       const u8 *key, int num_queue);
 int rndis_filter_receive(struct hv_device *dev,
 			struct hv_netvsc_packet *pkt,
 			void **data,

drivers/net/hyperv/netvsc_drv.c

@@ -1059,6 +1059,48 @@ static void netvsc_poll_controller(struct net_device *net)
 }
 #endif
 
+static u32 netvsc_get_rxfh_key_size(struct net_device *dev)
+{
+	return NETVSC_HASH_KEYLEN;
+}
+
+static u32 netvsc_rss_indir_size(struct net_device *dev)
+{
+	return 0;
+}
+
+static int netvsc_get_rxfh(struct net_device *dev, u32 *indir, u8 *key,
+			   u8 *hfunc)
+{
+	struct net_device_context *ndc = netdev_priv(dev);
+	struct netvsc_device *ndev = ndc->nvdev;
+	struct rndis_device *rndis_dev = ndev->extension;
+
+	if (hfunc)
+		*hfunc = ETH_RSS_HASH_TOP;	/* Toeplitz */
+
+	if (key)
+		memcpy(key, rndis_dev->rss_key, NETVSC_HASH_KEYLEN);
+
+	return 0;
+}
+
+static int netvsc_set_rxfh(struct net_device *dev, const u32 *indir,
+			   const u8 *key, const u8 hfunc)
+{
+	struct net_device_context *ndc = netdev_priv(dev);
+	struct netvsc_device *ndev = ndc->nvdev;
+	struct rndis_device *rndis_dev = ndev->extension;
+
+	if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
+		return -EOPNOTSUPP;
+
+	if (!key || memcmp(key, rndis_dev->rss_key, NETVSC_HASH_KEYLEN) == 0)
+		return 0; /* no change */
+
+	return rndis_filter_set_rss_param(rndis_dev, key, ndev->num_chn);
+}
+
 static const struct ethtool_ops ethtool_ops = {
 	.get_drvinfo	= netvsc_get_drvinfo,
 	.get_link	= ethtool_op_get_link,
@@ -1071,6 +1113,10 @@ static const struct ethtool_ops ethtool_ops = {
 	.get_settings	= netvsc_get_settings,
 	.set_settings	= netvsc_set_settings,
 	.get_rxnfc	= netvsc_get_rxnfc,
+	.get_rxfh_key_size = netvsc_get_rxfh_key_size,
+	.get_rxfh_indir_size = netvsc_rss_indir_size,
+	.get_rxfh	= netvsc_get_rxfh,
+	.set_rxfh	= netvsc_set_rxfh,
 };
 
 static const struct net_device_ops device_ops = {

drivers/net/hyperv/rndis_filter.c

@@ -57,6 +57,14 @@ struct rndis_request {
 	u8 request_ext[RNDIS_EXT_LEN];
 };
 
+static const u8 netvsc_hash_key[NETVSC_HASH_KEYLEN] = {
+	0x6d, 0x5a, 0x56, 0xda, 0x25, 0x5b, 0x0e, 0xc2,
+	0x41, 0x67, 0x25, 0x3d, 0x43, 0xa3, 0x8f, 0xb0,
+	0xd0, 0xca, 0x2b, 0xcb, 0xae, 0x7b, 0x30, 0xb4,
+	0x77, 0xcb, 0x2d, 0xa3, 0x80, 0x30, 0xf2, 0x0c,
+	0x6a, 0x42, 0xb7, 0x3b, 0xbe, 0xac, 0x01, 0xfa
+};
+
 static struct rndis_device *get_rndis_device(void)
 {
 	struct rndis_device *device;
@@ -729,23 +737,15 @@ rndis_filter_set_offload_params(struct net_device *ndev,
 	return ret;
 }
 
-static const u8 netvsc_hash_key[] = {
-	0x6d, 0x5a, 0x56, 0xda, 0x25, 0x5b, 0x0e, 0xc2,
-	0x41, 0x67, 0x25, 0x3d, 0x43, 0xa3, 0x8f, 0xb0,
-	0xd0, 0xca, 0x2b, 0xcb, 0xae, 0x7b, 0x30, 0xb4,
-	0x77, 0xcb, 0x2d, 0xa3, 0x80, 0x30, 0xf2, 0x0c,
-	0x6a, 0x42, 0xb7, 0x3b, 0xbe, 0xac, 0x01, 0xfa
-};
-#define HASH_KEYLEN ARRAY_SIZE(netvsc_hash_key)
-
-static int rndis_filter_set_rss_param(struct rndis_device *rdev, int num_queue)
+int rndis_filter_set_rss_param(struct rndis_device *rdev,
+			       const u8 *rss_key, int num_queue)
 {
 	struct net_device *ndev = rdev->ndev;
 	struct rndis_request *request;
 	struct rndis_set_request *set;
 	struct rndis_set_complete *set_complete;
 	u32 extlen = sizeof(struct ndis_recv_scale_param) +
-		     4*ITAB_NUM + HASH_KEYLEN;
+		     4 * ITAB_NUM + NETVSC_HASH_KEYLEN;
 	struct ndis_recv_scale_param *rssp;
 	u32 *itab;
 	u8 *keyp;
@@ -773,7 +773,7 @@ static int rndis_filter_set_rss_param(struct rndis_device *rdev, int num_queue)
 			 NDIS_HASH_TCP_IPV6;
 	rssp->indirect_tabsize = 4*ITAB_NUM;
 	rssp->indirect_taboffset = sizeof(struct ndis_recv_scale_param);
-	rssp->hashkey_size = HASH_KEYLEN;
+	rssp->hashkey_size = NETVSC_HASH_KEYLEN;
 	rssp->kashkey_offset = rssp->indirect_taboffset +
 			       rssp->indirect_tabsize;
 
@@ -784,8 +784,7 @@ static int rndis_filter_set_rss_param(struct rndis_device *rdev, int num_queue)
 
 	/* Set hask key values */
 	keyp = (u8 *)((unsigned long)rssp + rssp->kashkey_offset);
-	for (i = 0; i < HASH_KEYLEN; i++)
-		keyp[i] = netvsc_hash_key[i];
+	memcpy(keyp, rss_key, NETVSC_HASH_KEYLEN);
 
 	ret = rndis_filter_send_request(rdev, request);
 	if (ret != 0)
@@ -793,7 +792,9 @@ static int rndis_filter_set_rss_param(struct rndis_device *rdev, int num_queue)
 
 	wait_for_completion(&request->wait_event);
 	set_complete = &request->response_msg.msg.set_complete;
-	if (set_complete->status != RNDIS_STATUS_SUCCESS) {
+	if (set_complete->status == RNDIS_STATUS_SUCCESS)
+		memcpy(rdev->rss_key, rss_key, NETVSC_HASH_KEYLEN);
+	else {
 		netdev_err(ndev, "Fail to set RSS parameters:0x%x\n",
 			   set_complete->status);
 		ret = -EINVAL;
@@ -1235,7 +1236,8 @@ int rndis_filter_device_add(struct hv_device *dev,
 	net_device->num_chn = 1 +
 		init_packet->msg.v5_msg.subchn_comp.num_subchannels;
 
-	ret = rndis_filter_set_rss_param(rndis_device, net_device->num_chn);
+	ret = rndis_filter_set_rss_param(rndis_device, netvsc_hash_key,
+					 net_device->num_chn);
 
 	/*
 	 * Set the number of sub-channels to be received.