Merge branch 'ethtool-rss-track-rss-ctx-busy-from-core'

Daniel Zahka says:

====================
ethtool: rss: track rss ctx busy from core

This series prevents deletion of rss contexts that are
in use by ntuple filters from ethtool core.
====================

Link: https://patch.msgid.link/20241011183549.1581021-1-daniel.zahka@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net/ethtool/common.c

@@ -684,6 +684,54 @@ int ethtool_check_max_channel(struct net_device *dev,
 	return 0;
 }
 
+int ethtool_check_rss_ctx_busy(struct net_device *dev, u32 rss_context)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct ethtool_rxnfc *info;
+	int rc, i, rule_cnt;
+
+	if (!ops->get_rxnfc)
+		return 0;
+
+	rule_cnt = ethtool_get_rxnfc_rule_count(dev);
+	if (!rule_cnt)
+		return 0;
+
+	if (rule_cnt < 0)
+		return -EINVAL;
+
+	info = kvzalloc(struct_size(info, rule_locs, rule_cnt), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->cmd = ETHTOOL_GRXCLSRLALL;
+	info->rule_cnt = rule_cnt;
+	rc = ops->get_rxnfc(dev, info, info->rule_locs);
+	if (rc)
+		goto out_free;
+
+	for (i = 0; i < rule_cnt; i++) {
+		struct ethtool_rxnfc rule_info = {
+			.cmd = ETHTOOL_GRXCLSRULE,
+			.fs.location = info->rule_locs[i],
+		};
+
+		rc = ops->get_rxnfc(dev, &rule_info, NULL);
+		if (rc)
+			goto out_free;
+
+		if (rule_info.fs.flow_type & FLOW_RSS &&
+		    rule_info.rss_context == rss_context) {
+			rc = -EBUSY;
+			goto out_free;
+		}
+	}
+
+out_free:
+	kvfree(info);
+	return rc;
+}
+
 int ethtool_check_ops(const struct ethtool_ops *ops)
 {
 	if (WARN_ON(ops->set_coalesce && !ops->supported_coalesce_params))

net/ethtool/common.h

@@ -47,6 +47,7 @@ bool convert_legacy_settings_to_link_ksettings(
 int ethtool_check_max_channel(struct net_device *dev,
 			      struct ethtool_channels channels,
 			      struct genl_info *info);
+int ethtool_check_rss_ctx_busy(struct net_device *dev, u32 rss_context);
 int __ethtool_get_ts_info(struct net_device *dev, struct kernel_ethtool_ts_info *info);
 
 extern const struct ethtool_phy_ops *ethtool_phy_ops;

net/ethtool/ioctl.c

@@ -1462,6 +1462,13 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
 		mutex_lock(&dev->ethtool->rss_lock);
 		locked = true;
 	}
+
+	if (rxfh.rss_context && rxfh_dev.rss_delete) {
+		ret = ethtool_check_rss_ctx_busy(dev, rxfh.rss_context);
+		if (ret)
+			goto out;
+	}
+
 	if (create) {
 		if (rxfh_dev.rss_delete) {
 			ret = -EINVAL;

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

@@ -6,7 +6,7 @@
 from lib.py import ksft_run, ksft_pr, ksft_exit, ksft_eq, ksft_ne, ksft_ge, ksft_lt
 from lib.py import NetDrvEpEnv
 from lib.py import EthtoolFamily, NetdevFamily
-from lib.py import KsftSkipEx
+from lib.py import KsftSkipEx, KsftFailEx
 from lib.py import rand_port
 from lib.py import ethtool, ip, defer, GenerateTraffic, CmdExitFailure
 
@@ -606,6 +606,33 @@ def test_rss_context_overlap2(cfg):
     test_rss_context_overlap(cfg, True)
 
 
+def test_delete_rss_context_busy(cfg):
+    """
+    Test that deletion returns -EBUSY when an rss context is being used
+    by an ntuple filter.
+    """
+
+    require_ntuple(cfg)
+
+    # create additional rss context
+    ctx_id = ethtool_create(cfg, "-X", "context new")
+    ctx_deleter = defer(ethtool, f"-X {cfg.ifname} context {ctx_id} delete")
+
+    # utilize context from ntuple filter
+    port = rand_port()
+    flow = f"flow-type tcp{cfg.addr_ipver} dst-port {port} context {ctx_id}"
+    ntuple_id = ethtool_create(cfg, "-N", flow)
+    defer(ethtool, f"-N {cfg.ifname} delete {ntuple_id}")
+
+    # attempt to delete in-use context
+    try:
+        ctx_deleter.exec_only()
+        ctx_deleter.cancel()
+        raise KsftFailEx(f"deleted context {ctx_id} used by rule {ntuple_id}")
+    except CmdExitFailure:
+        pass
+
+
 def main() -> None:
     with NetDrvEpEnv(__file__, nsim_test=False) as cfg:
         cfg.ethnl = EthtoolFamily()
@@ -616,7 +643,8 @@ def main() -> None:
                   test_rss_context, test_rss_context4, test_rss_context32,
                   test_rss_context_dump, test_rss_context_queue_reconfigure,
                   test_rss_context_overlap, test_rss_context_overlap2,
-                  test_rss_context_out_of_order, test_rss_context4_create_with_cfg],
+                  test_rss_context_out_of_order, test_rss_context4_create_with_cfg,
+                  test_delete_rss_context_busy],
                  args=(cfg, ))
     ksft_exit()