selftests: drv-net: rss: Generate unique ports for RSS context tests

The RSS ctx tests rely on NFC rules with unique ports to steer packets
to the correct ctx. This updates the test to use the new rand_ports()
helper to guarantee the ports are unique.

Manual testing shows that generating 32 ports with the existing method
would result in at least one duplicate 4% of the time.

Signed-off-by: Dimitri Daskalakis <dimitri.daskalakis1@gmail.com>
Link: https://patch.msgid.link/20260224224659.1507082-3-dimitri.daskalakis1@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -9,7 +9,7 @@ from lib.py import ksft_eq, ksft_ne, ksft_ge, ksft_in, ksft_lt, ksft_true, ksft_
 from lib.py import NetDrvEpEnv
 from lib.py import EthtoolFamily, NetdevFamily
 from lib.py import KsftSkipEx, KsftFailEx
-from lib.py import rand_port
+from lib.py import rand_port, rand_ports
 from lib.py import ethtool, ip, defer, GenerateTraffic, CmdExitFailure
 
 
@@ -452,7 +452,7 @@ def test_rss_context(cfg, ctx_cnt=1, create_with_cfg=None):
         except:
             raise KsftSkipEx("Not enough queues for the test")
 
-    ports = []
+    ports = rand_ports(ctx_cnt)
 
     # Use queues 0 and 1 for normal traffic
     ethtool(f"-X {cfg.ifname} equal 2")
@@ -486,7 +486,6 @@ def test_rss_context(cfg, ctx_cnt=1, create_with_cfg=None):
         ksft_eq(min(data['rss-indirection-table']), 2 + i * 2, "Unexpected context cfg: " + str(data))
         ksft_eq(max(data['rss-indirection-table']), 2 + i * 2 + 1, "Unexpected context cfg: " + str(data))
 
-        ports.append(rand_port())
         flow = f"flow-type tcp{cfg.addr_ipver} dst-ip {cfg.addr} dst-port {ports[i]} context {ctx_id}"
         ntuple = ethtool_create(cfg, "-N", flow)
         defer(ethtool, f"-N {cfg.ifname} delete {ntuple}")
@@ -542,7 +541,7 @@ def test_rss_context_out_of_order(cfg, ctx_cnt=4):
 
     ntuple = []
     ctx = []
-    ports = []
+    ports = rand_ports(ctx_cnt)
 
     def remove_ctx(idx):
         ntuple[idx].exec()
@@ -574,7 +573,6 @@ def test_rss_context_out_of_order(cfg, ctx_cnt=4):
         ctx_id = ethtool_create(cfg, "-X", f"context new start {2 + i * 2} equal 2")
         ctx.append(defer(ethtool, f"-X {cfg.ifname} context {ctx_id} delete"))
 
-        ports.append(rand_port())
         flow = f"flow-type tcp{cfg.addr_ipver} dst-ip {cfg.addr} dst-port {ports[i]} context {ctx_id}"
         ntuple_id = ethtool_create(cfg, "-N", flow)
         ntuple.append(defer(ethtool, f"-N {cfg.ifname} delete {ntuple_id}"))
@@ -788,9 +786,10 @@ def test_rss_default_context_rule(cfg):
     ethtool(f"-N {cfg.ifname} {flow_generic}")
     defer(ethtool, f"-N {cfg.ifname} delete 1")
 
+    ports = rand_ports(2)
     # Specific high-priority rule for a random port that should stay on context 0.
     # Assign loc 0 so it is evaluated before the generic rule.
-    port_main = rand_port()
+    port_main = ports[0]
     flow_main = f"flow-type tcp{cfg.addr_ipver} dst-ip {cfg.addr} dst-port {port_main} context 0 loc 0"
     ethtool(f"-N {cfg.ifname} {flow_main}")
     defer(ethtool, f"-N {cfg.ifname} delete 0")
@@ -803,7 +802,7 @@ def test_rss_default_context_rule(cfg):
                           'empty' : (2, 3) })
 
     # And that traffic for any other port is steered to the new context
-    port_other = rand_port()
+    port_other = ports[1]
     _send_traffic_check(cfg, port_other, f"context {ctx_id}",
                         { 'target': (2, 3),
                           'noise' : (0, 1) })