Merge branch 'ethtool-rss-fixes' into main

Jakub Kicinski says;

====================
ethtool: more RSS fixes

More fixes for RSS setting. First two patches fix my own bugs
in bnxt conversion to the new API. The third patch fixes
what seems to be a 10 year old issue (present since the Linux
RSS API was created). Fourth patch fixes an issue with
the XArray state being out of sync. And then a small test.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c

@@ -1863,8 +1863,14 @@ static void bnxt_modify_rss(struct bnxt *bp, struct ethtool_rxfh_context *ctx,
 }
 
 static int bnxt_rxfh_context_check(struct bnxt *bp,
+				   const struct ethtool_rxfh_param *rxfh,
 				   struct netlink_ext_ack *extack)
 {
+	if (rxfh->hfunc && rxfh->hfunc != ETH_RSS_HASH_TOP) {
+		NL_SET_ERR_MSG_MOD(extack, "RSS hash function not supported");
+		return -EOPNOTSUPP;
+	}
+
 	if (!BNXT_SUPPORTS_MULTI_RSS_CTX(bp)) {
 		NL_SET_ERR_MSG_MOD(extack, "RSS contexts not supported");
 		return -EOPNOTSUPP;
@@ -1888,7 +1894,7 @@ static int bnxt_create_rxfh_context(struct net_device *dev,
 	struct bnxt_vnic_info *vnic;
 	int rc;
 
-	rc = bnxt_rxfh_context_check(bp, extack);
+	rc = bnxt_rxfh_context_check(bp, rxfh, extack);
 	if (rc)
 		return rc;
 
@@ -1915,8 +1921,12 @@ static int bnxt_create_rxfh_context(struct net_device *dev,
 	if (rc)
 		goto out;
 
+	/* Populate defaults in the context */
 	bnxt_set_dflt_rss_indir_tbl(bp, ctx);
+	ctx->hfunc = ETH_RSS_HASH_TOP;
 	memcpy(vnic->rss_hash_key, bp->rss_hash_key, HW_HASH_KEY_SIZE);
+	memcpy(ethtool_rxfh_context_key(ctx),
+	       bp->rss_hash_key, HW_HASH_KEY_SIZE);
 
 	rc = bnxt_hwrm_vnic_alloc(bp, vnic, 0, bp->rx_nr_rings);
 	if (rc) {
@@ -1953,7 +1963,7 @@ static int bnxt_modify_rxfh_context(struct net_device *dev,
 	struct bnxt_rss_ctx *rss_ctx;
 	int rc;
 
-	rc = bnxt_rxfh_context_check(bp, extack);
+	rc = bnxt_rxfh_context_check(bp, rxfh, extack);
 	if (rc)
 		return rc;
 

net/ethtool/ioctl.c

@@ -1331,13 +1331,13 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	u32 rss_cfg_offset = offsetof(struct ethtool_rxfh, rss_config[0]);
 	const struct ethtool_ops *ops = dev->ethtool_ops;
 	u32 dev_indir_size = 0, dev_key_size = 0, i;
+	u32 user_indir_len = 0, indir_bytes = 0;
 	struct ethtool_rxfh_param rxfh_dev = {};
 	struct ethtool_rxfh_context *ctx = NULL;
 	struct netlink_ext_ack *extack = NULL;
 	struct ethtool_rxnfc rx_rings;
 	struct ethtool_rxfh rxfh;
 	bool locked = false; /* dev->ethtool->rss_lock taken */
-	u32 indir_bytes = 0;
 	bool create = false;
 	u8 *rss_config;
 	int ret;
@@ -1382,10 +1382,9 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	     rxfh.input_xfrm == RXH_XFRM_NO_CHANGE))
 		return -EINVAL;
 
-	if (rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE)
 	indir_bytes = dev_indir_size * sizeof(rxfh_dev.indir[0]);
 
-	rss_config = kzalloc(indir_bytes + rxfh.key_size, GFP_USER);
+	rss_config = kzalloc(indir_bytes + dev_key_size, GFP_USER);
 	if (!rss_config)
 		return -ENOMEM;
 
@@ -1400,6 +1399,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	 */
 	if (rxfh.indir_size &&
 	    rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE) {
+		user_indir_len = indir_bytes;
 		rxfh_dev.indir = (u32 *)rss_config;
 		rxfh_dev.indir_size = dev_indir_size;
 		ret = ethtool_copy_validate_indir(rxfh_dev.indir,
@@ -1426,7 +1426,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		rxfh_dev.key_size = dev_key_size;
 		rxfh_dev.key = rss_config + indir_bytes;
 		if (copy_from_user(rxfh_dev.key,
-				   useraddr + rss_cfg_offset + indir_bytes,
+				   useraddr + rss_cfg_offset + user_indir_len,
 				   rxfh.key_size)) {
 			ret = -EFAULT;
 			goto out;
@@ -1474,16 +1474,21 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 	rxfh_dev.input_xfrm = rxfh.input_xfrm;
 
 	if (rxfh.rss_context && ops->create_rxfh_context) {
-		if (create)
+		if (create) {
 			ret = ops->create_rxfh_context(dev, ctx, &rxfh_dev,
 						       extack);
-		else if (rxfh_dev.rss_delete)
+			/* Make sure driver populates defaults */
+			WARN_ON_ONCE(!ret && !rxfh_dev.key &&
+				     !memchr_inv(ethtool_rxfh_context_key(ctx),
+						 0, ctx->key_size));
+		} else if (rxfh_dev.rss_delete) {
 			ret = ops->remove_rxfh_context(dev, ctx,
 						       rxfh.rss_context,
 						       extack);
-		else
+		} else {
 			ret = ops->modify_rxfh_context(dev, ctx, &rxfh_dev,
 						       extack);
+		}
 	} else {
 		ret = ops->set_rxfh(dev, &rxfh_dev, extack);
 	}
@@ -1522,6 +1527,22 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 			kfree(ctx);
 			goto out;
 		}
+
+		/* Fetch the defaults for the old API, in the new API drivers
+		 * should write defaults into ctx themselves.
+		 */
+		rxfh_dev.indir = (u32 *)rss_config;
+		rxfh_dev.indir_size = dev_indir_size;
+
+		rxfh_dev.key = rss_config + indir_bytes;
+		rxfh_dev.key_size = dev_key_size;
+
+		ret = ops->get_rxfh(dev, &rxfh_dev);
+		if (WARN_ON(ret)) {
+			xa_erase(&dev->ethtool->rss_ctx, rxfh.rss_context);
+			kfree(ctx);
+			goto out;
+		}
 	}
 	if (rxfh_dev.rss_delete) {
 		WARN_ON(xa_erase(&dev->ethtool->rss_ctx, rxfh.rss_context) != ctx);
@@ -1530,12 +1551,14 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		if (rxfh_dev.indir) {
 			for (i = 0; i < dev_indir_size; i++)
 				ethtool_rxfh_context_indir(ctx)[i] = rxfh_dev.indir[i];
-			ctx->indir_configured = 1;
+			ctx->indir_configured =
+				rxfh.indir_size &&
+				rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE;
 		}
 		if (rxfh_dev.key) {
 			memcpy(ethtool_rxfh_context_key(ctx), rxfh_dev.key,
 			       dev_key_size);
-			ctx->key_configured = 1;
+			ctx->key_configured = !!rxfh.key_size;
 		}
 		if (rxfh_dev.hfunc != ETH_RSS_HASH_NO_CHANGE)
 			ctx->hfunc = rxfh_dev.hfunc;

tools/testing/selftests/drivers/net/hw/rss_ctx.py

@@ -19,6 +19,15 @@ def _rss_key_rand(length):
     return [random.randint(0, 255) for _ in range(length)]
 
 
+def _rss_key_check(cfg, data=None, context=0):
+    if data is None:
+        data = get_rss(cfg, context=context)
+    if 'rss-hash-key' not in data:
+        return
+    non_zero = [x for x in data['rss-hash-key'] if x != 0]
+    ksft_eq(bool(non_zero), True, comment=f"RSS key is all zero {data['rss-hash-key']}")
+
+
 def get_rss(cfg, context=0):
     return ethtool(f"-x {cfg.ifname} context {context}", json=True)[0]
 
@@ -90,8 +99,9 @@ def _send_traffic_check(cfg, port, name, params):
 def test_rss_key_indir(cfg):
     """Test basics like updating the main RSS key and indirection table."""
 
-    if len(_get_rx_cnts(cfg)) < 2:
-        KsftSkipEx("Device has only one queue (or doesn't support queue stats)")
+    qcnt = len(_get_rx_cnts(cfg))
+    if qcnt < 3:
+        KsftSkipEx("Device has fewer than 3 queues (or doesn't support queue stats)")
 
     data = get_rss(cfg)
     want_keys = ['rss-hash-key', 'rss-hash-function', 'rss-indirection-table']
@@ -101,6 +111,7 @@ def test_rss_key_indir(cfg):
         if not data[k]:
             raise KsftFailEx(f"ethtool results empty for '{k}': {data[k]}")
 
+    _rss_key_check(cfg, data=data)
     key_len = len(data['rss-hash-key'])
 
     # Set the key
@@ -110,9 +121,26 @@ def test_rss_key_indir(cfg):
     data = get_rss(cfg)
     ksft_eq(key, data['rss-hash-key'])
 
+    # Set the indirection table and the key together
+    key = _rss_key_rand(key_len)
+    ethtool(f"-X {cfg.ifname} equal 3 hkey " + _rss_key_str(key))
+    reset_indir = defer(ethtool, f"-X {cfg.ifname} default")
+
+    data = get_rss(cfg)
+    _rss_key_check(cfg, data=data)
+    ksft_eq(0, min(data['rss-indirection-table']))
+    ksft_eq(2, max(data['rss-indirection-table']))
+
+    # Reset indirection table and set the key
+    key = _rss_key_rand(key_len)
+    ethtool(f"-X {cfg.ifname} default hkey " + _rss_key_str(key))
+    data = get_rss(cfg)
+    _rss_key_check(cfg, data=data)
+    ksft_eq(0, min(data['rss-indirection-table']))
+    ksft_eq(qcnt - 1, max(data['rss-indirection-table']))
+
     # Set the indirection table
     ethtool(f"-X {cfg.ifname} equal 2")
-    reset_indir = defer(ethtool, f"-X {cfg.ifname} default")
     data = get_rss(cfg)
     ksft_eq(0, min(data['rss-indirection-table']))
     ksft_eq(1, max(data['rss-indirection-table']))
@@ -317,8 +345,11 @@ def test_rss_context(cfg, ctx_cnt=1, create_with_cfg=None):
             ctx_cnt = i
             break
 
+        _rss_key_check(cfg, context=ctx_id)
+
         if not create_with_cfg:
             ethtool(f"-X {cfg.ifname} context {ctx_id} {want_cfg}")
+            _rss_key_check(cfg, context=ctx_id)
 
         # Sanity check the context we just created
         data = get_rss(cfg, ctx_id)