netdevsim: allow normal queue reset while down

Resetting queues while the device is down should be legal.
Allow it, test it. Ideally we'd test this with a real device
supporting devmem but I don't have access to such devices.

Reviewed-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20250206225638.1387810-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index 42f247cbdceecbadf27f7090c030aa5bd240c18a..9b394ddc5206a7a5ca5440341551aac50c43e20c 100644 (file)
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -645,8 +645,11 @@ nsim_queue_mem_alloc(struct net_device *dev, void *per_queue_mem, int idx)
        if (ns->rq_reset_mode > 3)
                return -EINVAL;
 
-       if (ns->rq_reset_mode == 1)
+       if (ns->rq_reset_mode == 1) {
+               if (!netif_running(ns->netdev))
+                       return -ENETDOWN;
                return nsim_create_page_pool(&qmem->pp, &ns->rq[idx]->napi);
+       }
 
        qmem->rq = nsim_queue_alloc();
        if (!qmem->rq)
@@ -754,11 +757,6 @@ nsim_qreset_write(struct file *file, const char __user *data,
                return -EINVAL;
 
        rtnl_lock();
-       if (!netif_running(ns->netdev)) {
-               ret = -ENETDOWN;
-               goto exit_unlock;
-       }
-
        if (queue >= ns->netdev->real_num_rx_queues) {
                ret = -EINVAL;
                goto exit_unlock;

diff --git a/tools/testing/selftests/net/nl_netdev.py b/tools/testing/selftests/net/nl_netdev.py
index 93e8cb671c3d9dd1b12667f5579e69ecd92e8e83..beaee5e4e2aaba63066677c74a8833edde873b19 100755 (executable)
--- a/tools/testing/selftests/net/nl_netdev.py
+++ b/tools/testing/selftests/net/nl_netdev.py
@@ -35,6 +35,21 @@ def napi_list_check(nf) -> None:
                         comment=f"queue count after reset queue {q} mode {i}")
 
 
+def nsim_rxq_reset_down(nf) -> None:
+    """
+    Test that the queue API supports resetting a queue
+    while the interface is down. We should convert this
+    test to testing real HW once more devices support
+    queue API.
+    """
+    with NetdevSimDev(queue_count=4) as nsimdev:
+        nsim = nsimdev.nsims[0]
+
+        ip(f"link set dev {nsim.ifname} down")
+        for i in [0, 2, 3]:
+            nsim.dfs_write("queue_reset", f"1 {i}")
+
+
 def page_pool_check(nf) -> None:
     with NetdevSimDev() as nsimdev:
         nsim = nsimdev.nsims[0]
@@ -106,7 +121,8 @@ def page_pool_check(nf) -> None:
 
 def main() -> None:
     nf = NetdevFamily()
-    ksft_run([empty_check, lo_check, page_pool_check, napi_list_check],
+    ksft_run([empty_check, lo_check, page_pool_check, napi_list_check,
+              nsim_rxq_reset_down],
              args=(nf, ))
     ksft_exit()