[PATCH net-next v2 0/2] netdevsim: add NAPI support

[PATCH net-next v2 0/2] netdevsim: add NAPI support

[David Wei]

Add NAPI support to netdevsim and register its Rx queues with NAPI
instances. Then add a selftest using the new netdev Python selftest
infra to exercise the existing Netdev Netlink API, specifically the
queue-get API.

This expands test coverage and further fleshes out netdevsim as a test
device. It's still my goal to make it useful for testing things like
flow steering and ZC Rx.

-----
Changes since v1:
* Use sk_buff_head instead of a list for per-rq skb queue
* Drop napi_schedule() if skb queue is not empty in napi poll
* Remove netif_carrier_on() in open()
* Remove unused page pool ptr in struct netdevsim
* Up the netdev in NetDrvEnv automatically
* Pass Netdev Netlink as a param instead of using globals
* Remove unused Python imports in selftest

David Wei (2):
  netdevsim: add NAPI support
  net: selftest: add test for netdev netlink queue-get API

 drivers/net/netdevsim/netdev.c                | 210 +++++++++++++++++-
 drivers/net/netdevsim/netdevsim.h             |   8 +-
 tools/testing/selftests/drivers/net/Makefile  |   1 +
 .../selftests/drivers/net/lib/py/env.py       |   6 +-
 tools/testing/selftests/drivers/net/queues.py |  59 +++++
 tools/testing/selftests/net/lib/py/nsim.py    |   4 +-
 6 files changed, 272 insertions(+), 16 deletions(-)
 create mode 100755 tools/testing/selftests/drivers/net/queues.py

-- 
2.43.0

[PATCH net-next v2 1/2] netdevsim: add NAPI support

[David Wei]

Add NAPI support to netdevim, similar to veth.

* Add a nsim_rq rx queue structure to hold a NAPI instance and a skb
  queue.
* During xmit, store the skb in the peer skb queue and schedule NAPI.
* During napi_poll(), drain the skb queue and pass up the stack.
* Add assoc between rxq and NAPI instance using netif_queue_set_napi().

Signed-off-by: David Wei <dw@davidwei.uk>
---
 drivers/net/netdevsim/netdev.c    | 210 ++++++++++++++++++++++++++++--
 drivers/net/netdevsim/netdevsim.h |   8 +-
 2 files changed, 206 insertions(+), 12 deletions(-)

diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index d127856f8f36..c19318d8b1bc 100644
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -28,11 +28,33 @@
 
 #include "netdevsim.h"
 
+#define NSIM_RING_SIZE		256
+
+static int nsim_napi_rx(struct nsim_rq *rq, struct sk_buff *skb)
+{
+	if (skb_queue_len(&rq->skb_queue) > NSIM_RING_SIZE) {
+		dev_kfree_skb_any(skb);
+		return NET_RX_DROP;
+	}
+
+	skb_queue_tail(&rq->skb_queue, skb);
+	return NET_RX_SUCCESS;
+}
+
+static int nsim_forward_skb(struct net_device *dev, struct sk_buff *skb,
+			    struct nsim_rq *rq)
+{
+	return __dev_forward_skb(dev, skb) ?: nsim_napi_rx(rq, skb);
+}
+
 static netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct netdevsim *ns = netdev_priv(dev);
+	struct net_device *peer_dev;
 	unsigned int len = skb->len;
 	struct netdevsim *peer_ns;
+	struct nsim_rq *rq;
+	int rxq;
 
 	rcu_read_lock();
 	if (!nsim_ipsec_tx(ns, skb))
@@ -42,10 +64,18 @@ static netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (!peer_ns)
 		goto out_drop_free;
 
+	peer_dev = peer_ns->netdev;
+	rxq = skb_get_queue_mapping(skb);
+	if (rxq >= peer_dev->num_rx_queues)
+		rxq = rxq % peer_dev->num_rx_queues;
+	rq = &peer_ns->rq[rxq];
+
 	skb_tx_timestamp(skb);
-	if (unlikely(dev_forward_skb(peer_ns->netdev, skb) == NET_RX_DROP))
+	if (unlikely(nsim_forward_skb(peer_dev, skb, rq) == NET_RX_DROP))
 		goto out_drop_cnt;
 
+	napi_schedule(&rq->napi);
+
 	rcu_read_unlock();
 	u64_stats_update_begin(&ns->syncp);
 	ns->tx_packets++;
@@ -300,25 +330,147 @@ static int nsim_get_iflink(const struct net_device *dev)
 	return iflink;
 }
 
+static int nsim_rcv(struct nsim_rq *rq, int budget)
+{
+	struct sk_buff *skb;
+	int i;
+
+	for (i = 0; i < budget; i++) {
+		if (skb_queue_empty(&rq->skb_queue))
+			break;
+
+		skb = skb_dequeue(&rq->skb_queue);
+		netif_receive_skb(skb);
+	}
+
+	return i;
+}
+
+static int nsim_poll(struct napi_struct *napi, int budget)
+{
+	struct nsim_rq *rq = container_of(napi, struct nsim_rq, napi);
+	int done;
+
+	done = nsim_rcv(rq, budget);
+
+	napi_complete_done(napi, 0);
+
+	return done;
+}
+
+static int nsim_create_page_pool(struct nsim_rq *rq)
+{
+	struct page_pool_params p = {
+		.order = 0,
+		.pool_size = NSIM_RING_SIZE,
+		.nid = NUMA_NO_NODE,
+		.dev = &rq->napi.dev->dev,
+		.napi = &rq->napi,
+		.dma_dir = DMA_BIDIRECTIONAL,
+		.netdev = rq->napi.dev,
+	};
+
+	rq->page_pool = page_pool_create(&p);
+	if (IS_ERR(rq->page_pool)) {
+		int err = PTR_ERR(rq->page_pool);
+
+		rq->page_pool = NULL;
+		return err;
+	}
+	return 0;
+}
+
+static int nsim_init_napi(struct netdevsim *ns)
+{
+	struct net_device *dev = ns->netdev;
+	struct nsim_rq *rq;
+	int err, i;
+
+	for (i = 0; i < dev->num_rx_queues; i++) {
+		rq = &ns->rq[i];
+
+		netif_napi_add(dev, &rq->napi, nsim_poll);
+	}
+
+	for (i = 0; i < dev->num_rx_queues; i++) {
+		rq = &ns->rq[i];
+
+		err = nsim_create_page_pool(rq);
+		if (err)
+			goto err_pp_destroy;
+	}
+
+	return 0;
+
+err_pp_destroy:
+	while (i--) {
+		page_pool_destroy(ns->rq[i].page_pool);
+		ns->rq[i].page_pool = NULL;
+	}
+
+	for (i = 0; i < dev->num_rx_queues; i++)
+		__netif_napi_del(&ns->rq[i].napi);
+
+	return err;
+}
+
+static void nsim_enable_napi(struct netdevsim *ns)
+{
+	struct net_device *dev = ns->netdev;
+	int i;
+
+	for (i = 0; i < dev->num_rx_queues; i++) {
+		struct nsim_rq *rq = &ns->rq[i];
+
+		netif_queue_set_napi(dev, i, NETDEV_QUEUE_TYPE_RX, &rq->napi);
+		napi_enable(&rq->napi);
+	}
+}
+
 static int nsim_open(struct net_device *dev)
 {
 	struct netdevsim *ns = netdev_priv(dev);
-	struct page_pool_params pp = { 0 };
+	int err;
 
-	pp.pool_size = 128;
-	pp.dev = &dev->dev;
-	pp.dma_dir = DMA_BIDIRECTIONAL;
-	pp.netdev = dev;
+	err = nsim_init_napi(ns);
+	if (err)
+		return err;
+
+	nsim_enable_napi(ns);
+
+	return 0;
+}
+
+static void nsim_del_napi(struct netdevsim *ns)
+{
+	struct net_device *dev = ns->netdev;
+	int i;
+
+	for (i = 0; i < dev->num_rx_queues; i++) {
+		struct nsim_rq *rq = &ns->rq[i];
+
+		napi_disable(&rq->napi);
+		__netif_napi_del(&rq->napi);
+	}
+	synchronize_net();
 
-	ns->pp = page_pool_create(&pp);
-	return PTR_ERR_OR_ZERO(ns->pp);
+	for (i = 0; i < dev->num_rx_queues; i++) {
+		page_pool_destroy(ns->rq[i].page_pool);
+		ns->rq[i].page_pool = NULL;
+	}
 }
 
 static int nsim_stop(struct net_device *dev)
 {
 	struct netdevsim *ns = netdev_priv(dev);
+	struct netdevsim *peer;
+
+	netif_carrier_off(dev);
+	peer = rtnl_dereference(ns->peer);
+	if (peer)
+		netif_carrier_off(peer->netdev);
 
-	page_pool_destroy(ns->pp);
+	nsim_del_napi(ns);
 
 	return 0;
 }
@@ -437,7 +589,7 @@ nsim_pp_hold_write(struct file *file, const char __user *data,
 	if (!netif_running(ns->netdev) && val) {
 		ret = -ENETDOWN;
 	} else if (val) {
-		ns->page = page_pool_dev_alloc_pages(ns->pp);
+		ns->page = page_pool_dev_alloc_pages(ns->rq[0].page_pool);
 		if (!ns->page)
 			ret = -ENOMEM;
 	} else {
@@ -477,6 +629,35 @@ static void nsim_setup(struct net_device *dev)
 	dev->xdp_features = NETDEV_XDP_ACT_HW_OFFLOAD;
 }
 
+static int nsim_queue_init(struct netdevsim *ns)
+{
+	struct net_device *dev = ns->netdev;
+	int i;
+
+	ns->rq = kvcalloc(dev->num_rx_queues, sizeof(*ns->rq),
+			  GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
+	if (!ns->rq)
+		return -ENOMEM;
+
+	for (i = 0; i < dev->num_rx_queues; i++)
+		skb_queue_head_init(&ns->rq[i].skb_queue);
+
+	return 0;
+}
+
+static void nsim_queue_free(struct netdevsim *ns)
+{
+	struct net_device *dev = ns->netdev;
+	int i;
+
+	for (i = 0; i < dev->num_rx_queues; i++)
+		skb_queue_purge_reason(&ns->rq[i].skb_queue,
+				       SKB_DROP_REASON_QUEUE_PURGE);
+
+	kvfree(ns->rq);
+	ns->rq = NULL;
+}
+
 static int nsim_init_netdevsim(struct netdevsim *ns)
 {
 	struct mock_phc *phc;
@@ -495,10 +676,14 @@ static int nsim_init_netdevsim(struct netdevsim *ns)
 		goto err_phc_destroy;
 
 	rtnl_lock();
-	err = nsim_bpf_init(ns);
+	err = nsim_queue_init(ns);
 	if (err)
 		goto err_utn_destroy;
 
+	err = nsim_bpf_init(ns);
+	if (err)
+		goto err_rq_destroy;
+
 	nsim_macsec_init(ns);
 	nsim_ipsec_init(ns);
 
@@ -512,6 +697,8 @@ static int nsim_init_netdevsim(struct netdevsim *ns)
 	nsim_ipsec_teardown(ns);
 	nsim_macsec_teardown(ns);
 	nsim_bpf_uninit(ns);
+err_rq_destroy:
+	nsim_queue_free(ns);
 err_utn_destroy:
 	rtnl_unlock();
 	nsim_udp_tunnels_info_destroy(ns->netdev);
@@ -594,6 +781,7 @@ void nsim_destroy(struct netdevsim *ns)
 		nsim_ipsec_teardown(ns);
 		nsim_bpf_uninit(ns);
 	}
+	nsim_queue_free(ns);
 	rtnl_unlock();
 	if (nsim_dev_port_is_pf(ns->nsim_dev_port))
 		nsim_exit_netdevsim(ns);
diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index 7664ab823e29..bf02efa10956 100644
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -90,11 +90,18 @@ struct nsim_ethtool {
 	struct ethtool_fecparam fec;
 };
 
+struct nsim_rq {
+	struct napi_struct napi;
+	struct sk_buff_head skb_queue;
+	struct page_pool *page_pool;
+};
+
 struct netdevsim {
 	struct net_device *netdev;
 	struct nsim_dev *nsim_dev;
 	struct nsim_dev_port *nsim_dev_port;
 	struct mock_phc *phc;
+	struct nsim_rq *rq;
 
 	u64 tx_packets;
 	u64 tx_bytes;
@@ -125,7 +132,6 @@ struct netdevsim {
 		struct debugfs_u32_array dfs_ports[2];
 	} udp_ports;
 
-	struct page_pool *pp;
 	struct page *page;
 	struct dentry *pp_dfs;
 
-- 
2.43.0

[PATCH net-next v2 2/2] net: selftest: add test for netdev netlink queue-get API

[David Wei]

Add a selftest for netdev generic netlink. For now there is only a
single test that exercises the `queue-get` API.

The test works with netdevsim by default or with a real device by
setting NETIF.

Signed-off-by: David Wei <dw@davidwei.uk>
---
 tools/testing/selftests/drivers/net/Makefile  |  1 +
 .../selftests/drivers/net/lib/py/env.py       |  6 +-
 tools/testing/selftests/drivers/net/queues.py | 59 +++++++++++++++++++
 tools/testing/selftests/net/lib/py/nsim.py    |  4 +-
 4 files changed, 66 insertions(+), 4 deletions(-)
 create mode 100755 tools/testing/selftests/drivers/net/queues.py

diff --git a/tools/testing/selftests/drivers/net/Makefile b/tools/testing/selftests/drivers/net/Makefile
index 379cdb1960a7..118a73650dbc 100644
--- a/tools/testing/selftests/drivers/net/Makefile
+++ b/tools/testing/selftests/drivers/net/Makefile
@@ -3,5 +3,6 @@
 TEST_INCLUDES := $(wildcard lib/py/*.py)
 
 TEST_PROGS := stats.py
+TEST_PROGS += queues.py
 
 include ../../lib.mk
diff --git a/tools/testing/selftests/drivers/net/lib/py/env.py b/tools/testing/selftests/drivers/net/lib/py/env.py
index e1abe9491daf..0ac4e9e6cd84 100644
--- a/tools/testing/selftests/drivers/net/lib/py/env.py
+++ b/tools/testing/selftests/drivers/net/lib/py/env.py
@@ -7,7 +7,7 @@ from lib.py import ip
 from lib.py import NetdevSimDev
 
 class NetDrvEnv:
-    def __init__(self, src_path):
+    def __init__(self, src_path, **kwargs):
         self._ns = None
 
         self.env = os.environ.copy()
@@ -16,11 +16,13 @@ class NetDrvEnv:
         if 'NETIF' in self.env:
             self.dev = ip("link show dev " + self.env['NETIF'], json=True)[0]
         else:
-            self._ns = NetdevSimDev()
+            self._ns = NetdevSimDev(**kwargs)
             self.dev = self._ns.nsims[0].dev
         self.ifindex = self.dev['ifindex']
 
     def __enter__(self):
+        ip(f"link set dev {self.dev['ifname']} up")
+
         return self
 
     def __exit__(self, ex_type, ex_value, ex_tb):
diff --git a/tools/testing/selftests/drivers/net/queues.py b/tools/testing/selftests/drivers/net/queues.py
new file mode 100755
index 000000000000..c23cd5a932cb
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/queues.py
@@ -0,0 +1,59 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+from lib.py import ksft_run, ksft_eq, KsftSkipEx
+from lib.py import NetdevFamily
+from lib.py import NetDrvEnv
+from lib.py import cmd
+import glob
+
+
+def sys_get_queues(ifname) -> int:
+    folders = glob.glob(f'/sys/class/net/{ifname}/queues/rx-*')
+    return len(folders)
+
+
+def nl_get_queues(cfg, nl):
+    queues = nl.queue_get({'ifindex': cfg.ifindex}, dump=True)
+    if queues:
+        return len([q for q in queues if q['type'] == 'rx'])
+    return None
+
+
+def get_queues(cfg, nl) -> None:
+    queues = nl_get_queues(cfg, nl)
+    if not queues:
+        raise KsftSkipEx("queue-get not supported by device")
+
+    expected = sys_get_queues(cfg.dev['ifname'])
+    ksft_eq(queues, expected)
+
+
+def addremove_queues(cfg, nl) -> None:
+    queues = nl_get_queues(cfg, nl)
+    if not queues:
+        raise KsftSkipEx("queue-get not supported by device")
+
+    expected = sys_get_queues(cfg.dev['ifname'])
+    ksft_eq(queues, expected)
+
+    # reduce queue count by 1
+    expected = expected - 1
+    cmd(f"ethtool -L {cfg.dev['ifname']} combined {expected}")
+    queues = nl_get_queues(cfg, nl)
+    ksft_eq(queues, expected)
+
+    # increase queue count by 1
+    expected = expected + 1
+    cmd(f"ethtool -L {cfg.dev['ifname']} combined {expected}")
+    queues = nl_get_queues(cfg, nl)
+    ksft_eq(queues, expected)
+
+
+def main() -> None:
+    with NetDrvEnv(__file__, queue_count=3) as cfg:
+        ksft_run([get_queues, addremove_queues], args=(cfg, NetdevFamily()))
+
+
+if __name__ == "__main__":
+    main()
diff --git a/tools/testing/selftests/net/lib/py/nsim.py b/tools/testing/selftests/net/lib/py/nsim.py
index 06896cdf7c18..f571a8b3139b 100644
--- a/tools/testing/selftests/net/lib/py/nsim.py
+++ b/tools/testing/selftests/net/lib/py/nsim.py
@@ -49,7 +49,7 @@ class NetdevSimDev:
         with open(fullpath, "w") as f:
             f.write(val)
 
-    def __init__(self, port_count=1, ns=None):
+    def __init__(self, port_count=1, queue_count=1, ns=None):
         # nsim will spawn in init_net, we'll set to actual ns once we switch it there
         self.ns = None
 
@@ -59,7 +59,7 @@ class NetdevSimDev:
         addr = random.randrange(1 << 15)
         while True:
             try:
-                self.ctrl_write("new_device", "%u %u" % (addr, port_count))
+                self.ctrl_write("new_device", "%u %u %u" % (addr, port_count, queue_count))
             except OSError as e:
                 if e.errno == errno.ENOSPC:
                     addr = random.randrange(1 << 15)
-- 
2.43.0

Re: [PATCH net-next v2 0/2] netdevsim: add NAPI support

[Jakub Kicinski]

On Fri, 19 Apr 2024 15:08:55 -0700 David Wei wrote:
> Add NAPI support to netdevsim and register its Rx queues with NAPI
> instances. Then add a selftest using the new netdev Python selftest
> infra to exercise the existing Netdev Netlink API, specifically the
> queue-get API.

I haven't looked at the code but this makes the devlink test crash 
the kernel:

[ 1130.858677][T11010] KASAN: null-ptr-deref in range [0x0000000000000190-0x0000000000000197]
[ 1130.859158][T11010] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[1130.859478][T11010] RIP: 0010:skb_queue_purge_reason (./include/linux/skbuff.h:1846 net/core/skbuff.c:3821) 
[ 1130.859672][T11010] Code: f1 f1 f1 f1 c7 40 0c 00 00 00 f3 c7 40 10 f3 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 84 24 d8 00 00 00 48 89 f8 48 c1 e8 03 <80> 3c 10 00 0f 85 bb 02 00 00 48 8b 03 48 39 c3 0f 84 ed 01 00 00
All code
========
   0:	f1                   	int1
   1:	f1                   	int1
   2:	f1                   	int1
   3:	f1                   	int1
   4:	c7 40 0c 00 00 00 f3 	movl   $0xf3000000,0xc(%rax)
   b:	c7 40 10 f3 f3 f3 f3 	movl   $0xf3f3f3f3,0x10(%rax)
  12:	65 48 8b 04 25 28 00 	mov    %gs:0x28,%rax
  19:	00 00 
  1b:	48 89 84 24 d8 00 00 	mov    %rax,0xd8(%rsp)
  22:	00 
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
  2a:*	80 3c 10 00          	cmpb   $0x0,(%rax,%rdx,1)		<-- trapping instruction
  2e:	0f 85 bb 02 00 00    	jne    0x2ef
  34:	48 8b 03             	mov    (%rbx),%rax
  37:	48 39 c3             	cmp    %rax,%rbx
  3a:	0f 84 ed 01 00 00    	je     0x22d

Code starting with the faulting instruction
===========================================
   0:	80 3c 10 00          	cmpb   $0x0,(%rax,%rdx,1)
   4:	0f 85 bb 02 00 00    	jne    0x2c5
   a:	48 8b 03             	mov    (%rbx),%rax
   d:	48 39 c3             	cmp    %rax,%rbx
  10:	0f 84 ed 01 00 00    	je     0x203
[ 1130.860181][T11010] RSP: 0018:ffffc900044ff8e0 EFLAGS: 00010202
[ 1130.860367][T11010] RAX: 0000000000000032 RBX: 0000000000000190 RCX: 0000000000000001
[ 1130.860580][T11010] RDX: dffffc0000000000 RSI: 0000000000000055 RDI: 0000000000000190
[ 1130.860821][T11010] RBP: ffffc900044ff9f0 R08: 0000000000000001 R09: fffffbfff10468b4
[ 1130.861067][T11010] R10: 0000000000000003 R11: ffffffff84800130 R12: ffffed10010f7584
[ 1130.861312][T11010] R13: 0000000000000001 R14: 0000000000000055 R15: 1ffff9200089ff20
[ 1130.861543][T11010] FS:  00007f691c6ba740(0000) GS:ffff888036180000(0000) knlGS:0000000000000000
[ 1130.861801][T11010] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1130.861983][T11010] CR2: 000055d41b377ff0 CR3: 000000000988a003 CR4: 0000000000770ef0
[ 1130.862199][T11010] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1130.862408][T11010] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1130.862630][T11010] PKRU: 55555554
[ 1130.862745][T11010] Call Trace:
[ 1130.862876][T11010]  <TASK>
[1130.862954][T11010] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
[1130.863080][T11010] ? exc_general_protection (arch/x86/kernel/traps.c:702 arch/x86/kernel/traps.c:644) 
[1130.863256][T11010] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:617) 
[1130.863401][T11010] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[1130.863599][T11010] ? skb_queue_purge_reason (./include/linux/skbuff.h:1846 net/core/skbuff.c:3821) 
[1130.863755][T11010] ? __pfx_skb_queue_purge_reason (net/core/skbuff.c:3817) 
[1130.863954][T11010] ? unregister_netdevice_queue (net/core/dev.c:11123) 
[1130.864129][T11010] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[1130.864291][T11010] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11112) 
[1130.864469][T11010] nsim_destroy (drivers/net/netdevsim/netdev.c:653 drivers/net/netdevsim/netdev.c:784) netdevsim
[1130.864651][T11010] __nsim_dev_port_del (drivers/net/netdevsim/dev.c:426 drivers/net/netdevsim/dev.c:1426) netdevsim
[1130.864889][T11010] nsim_dev_reload_destroy (drivers/net/netdevsim/dev.c:591 drivers/net/netdevsim/dev.c:1655) netdevsim
[1130.865081][T11010] nsim_drv_remove (drivers/net/netdevsim/dev.c:1675) netdevsim
[1130.865250][T11010] device_release_driver_internal (drivers/base/dd.c:1272 drivers/base/dd.c:1293) 
-- 
pw-bot: cr

Re: [PATCH net-next v2 0/2] netdevsim: add NAPI support

[David Wei]

On 2024-04-19 6:47 pm, Jakub Kicinski wrote:
> On Fri, 19 Apr 2024 15:08:55 -0700 David Wei wrote:
>> Add NAPI support to netdevsim and register its Rx queues with NAPI
>> instances. Then add a selftest using the new netdev Python selftest
>> infra to exercise the existing Netdev Netlink API, specifically the
>> queue-get API.
> 
> I haven't looked at the code but this makes the devlink test crash 
> the kernel:

Sorry, I'll look into it.

> 
> [ 1130.858677][T11010] KASAN: null-ptr-deref in range [0x0000000000000190-0x0000000000000197]
> [ 1130.859158][T11010] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
> [1130.859478][T11010] RIP: 0010:skb_queue_purge_reason (./include/linux/skbuff.h:1846 net/core/skbuff.c:3821) 
> [ 1130.859672][T11010] Code: f1 f1 f1 f1 c7 40 0c 00 00 00 f3 c7 40 10 f3 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 84 24 d8 00 00 00 48 89 f8 48 c1 e8 03 <80> 3c 10 00 0f 85 bb 02 00 00 48 8b 03 48 39 c3 0f 84 ed 01 00 00
> All code
> ========
>    0:	f1                   	int1
>    1:	f1                   	int1
>    2:	f1                   	int1
>    3:	f1                   	int1
>    4:	c7 40 0c 00 00 00 f3 	movl   $0xf3000000,0xc(%rax)
>    b:	c7 40 10 f3 f3 f3 f3 	movl   $0xf3f3f3f3,0x10(%rax)
>   12:	65 48 8b 04 25 28 00 	mov    %gs:0x28,%rax
>   19:	00 00 
>   1b:	48 89 84 24 d8 00 00 	mov    %rax,0xd8(%rsp)
>   22:	00 
>   23:	48 89 f8             	mov    %rdi,%rax
>   26:	48 c1 e8 03          	shr    $0x3,%rax
>   2a:*	80 3c 10 00          	cmpb   $0x0,(%rax,%rdx,1)		<-- trapping instruction
>   2e:	0f 85 bb 02 00 00    	jne    0x2ef
>   34:	48 8b 03             	mov    (%rbx),%rax
>   37:	48 39 c3             	cmp    %rax,%rbx
>   3a:	0f 84 ed 01 00 00    	je     0x22d
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	80 3c 10 00          	cmpb   $0x0,(%rax,%rdx,1)
>    4:	0f 85 bb 02 00 00    	jne    0x2c5
>    a:	48 8b 03             	mov    (%rbx),%rax
>    d:	48 39 c3             	cmp    %rax,%rbx
>   10:	0f 84 ed 01 00 00    	je     0x203
> [ 1130.860181][T11010] RSP: 0018:ffffc900044ff8e0 EFLAGS: 00010202
> [ 1130.860367][T11010] RAX: 0000000000000032 RBX: 0000000000000190 RCX: 0000000000000001
> [ 1130.860580][T11010] RDX: dffffc0000000000 RSI: 0000000000000055 RDI: 0000000000000190
> [ 1130.860821][T11010] RBP: ffffc900044ff9f0 R08: 0000000000000001 R09: fffffbfff10468b4
> [ 1130.861067][T11010] R10: 0000000000000003 R11: ffffffff84800130 R12: ffffed10010f7584
> [ 1130.861312][T11010] R13: 0000000000000001 R14: 0000000000000055 R15: 1ffff9200089ff20
> [ 1130.861543][T11010] FS:  00007f691c6ba740(0000) GS:ffff888036180000(0000) knlGS:0000000000000000
> [ 1130.861801][T11010] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 1130.861983][T11010] CR2: 000055d41b377ff0 CR3: 000000000988a003 CR4: 0000000000770ef0
> [ 1130.862199][T11010] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [ 1130.862408][T11010] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [ 1130.862630][T11010] PKRU: 55555554
> [ 1130.862745][T11010] Call Trace:
> [ 1130.862876][T11010]  <TASK>
> [1130.862954][T11010] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
> [1130.863080][T11010] ? exc_general_protection (arch/x86/kernel/traps.c:702 arch/x86/kernel/traps.c:644) 
> [1130.863256][T11010] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:617) 
> [1130.863401][T11010] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
> [1130.863599][T11010] ? skb_queue_purge_reason (./include/linux/skbuff.h:1846 net/core/skbuff.c:3821) 
> [1130.863755][T11010] ? __pfx_skb_queue_purge_reason (net/core/skbuff.c:3817) 
> [1130.863954][T11010] ? unregister_netdevice_queue (net/core/dev.c:11123) 
> [1130.864129][T11010] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
> [1130.864291][T11010] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11112) 
> [1130.864469][T11010] nsim_destroy (drivers/net/netdevsim/netdev.c:653 drivers/net/netdevsim/netdev.c:784) netdevsim
> [1130.864651][T11010] __nsim_dev_port_del (drivers/net/netdevsim/dev.c:426 drivers/net/netdevsim/dev.c:1426) netdevsim
> [1130.864889][T11010] nsim_dev_reload_destroy (drivers/net/netdevsim/dev.c:591 drivers/net/netdevsim/dev.c:1655) netdevsim
> [1130.865081][T11010] nsim_drv_remove (drivers/net/netdevsim/dev.c:1675) netdevsim
> [1130.865250][T11010] device_release_driver_internal (drivers/base/dd.c:1272 drivers/base/dd.c:1293) 

Re: [PATCH net-next v2 2/2] net: selftest: add test for netdev netlink queue-get API

[Willem de Bruijn]

David Wei wrote:
> Add a selftest for netdev generic netlink. For now there is only a
> single test that exercises the `queue-get` API.
> 
> The test works with netdevsim by default or with a real device by
> setting NETIF.
> 
> Signed-off-by: David Wei <dw@davidwei.uk>
> ---
>  tools/testing/selftests/drivers/net/Makefile  |  1 +
>  .../selftests/drivers/net/lib/py/env.py       |  6 +-
>  tools/testing/selftests/drivers/net/queues.py | 59 +++++++++++++++++++
>  tools/testing/selftests/net/lib/py/nsim.py    |  4 +-
>  4 files changed, 66 insertions(+), 4 deletions(-)
>  create mode 100755 tools/testing/selftests/drivers/net/queues.py
> 
> diff --git a/tools/testing/selftests/drivers/net/Makefile b/tools/testing/selftests/drivers/net/Makefile
> index 379cdb1960a7..118a73650dbc 100644
> --- a/tools/testing/selftests/drivers/net/Makefile
> +++ b/tools/testing/selftests/drivers/net/Makefile
> @@ -3,5 +3,6 @@
>  TEST_INCLUDES := $(wildcard lib/py/*.py)
>  
>  TEST_PROGS := stats.py
> +TEST_PROGS += queues.py
>  
>  include ../../lib.mk
> diff --git a/tools/testing/selftests/drivers/net/lib/py/env.py b/tools/testing/selftests/drivers/net/lib/py/env.py
> index e1abe9491daf..0ac4e9e6cd84 100644
> --- a/tools/testing/selftests/drivers/net/lib/py/env.py
> +++ b/tools/testing/selftests/drivers/net/lib/py/env.py
> @@ -7,7 +7,7 @@ from lib.py import ip
>  from lib.py import NetdevSimDev
>  
>  class NetDrvEnv:
> -    def __init__(self, src_path):
> +    def __init__(self, src_path, **kwargs):
>          self._ns = None
>  
>          self.env = os.environ.copy()
> @@ -16,11 +16,13 @@ class NetDrvEnv:
>          if 'NETIF' in self.env:
>              self.dev = ip("link show dev " + self.env['NETIF'], json=True)[0]
>          else:
> -            self._ns = NetdevSimDev()
> +            self._ns = NetdevSimDev(**kwargs)
>              self.dev = self._ns.nsims[0].dev
>          self.ifindex = self.dev['ifindex']
>  
>      def __enter__(self):
> +        ip(f"link set dev {self.dev['ifname']} up")
> +
>          return self
>  
>      def __exit__(self, ex_type, ex_value, ex_tb):
> diff --git a/tools/testing/selftests/drivers/net/queues.py b/tools/testing/selftests/drivers/net/queues.py
> new file mode 100755
> index 000000000000..c23cd5a932cb
> --- /dev/null
> +++ b/tools/testing/selftests/drivers/net/queues.py
> @@ -0,0 +1,59 @@
> +#!/usr/bin/env python3
> +# SPDX-License-Identifier: GPL-2.0
> +
> +from lib.py import ksft_run, ksft_eq, KsftSkipEx
> +from lib.py import NetdevFamily
> +from lib.py import NetDrvEnv
> +from lib.py import cmd
> +import glob
> +
> +
> +def sys_get_queues(ifname) -> int:
> +    folders = glob.glob(f'/sys/class/net/{ifname}/queues/rx-*')
> +    return len(folders)
> +
> +
> +def nl_get_queues(cfg, nl):
> +    queues = nl.queue_get({'ifindex': cfg.ifindex}, dump=True)
> +    if queues:
> +        return len([q for q in queues if q['type'] == 'rx'])
> +    return None
> +
> +
> +def get_queues(cfg, nl) -> None:
> +    queues = nl_get_queues(cfg, nl)
> +    if not queues:
> +        raise KsftSkipEx("queue-get not supported by device")
> +
> +    expected = sys_get_queues(cfg.dev['ifname'])
> +    ksft_eq(queues, expected)
> +
> +
> +def addremove_queues(cfg, nl) -> None:
> +    queues = nl_get_queues(cfg, nl)
> +    if not queues:
> +        raise KsftSkipEx("queue-get not supported by device")
> +
> +    expected = sys_get_queues(cfg.dev['ifname'])
> +    ksft_eq(queues, expected)
> +

This is a copy of get_queues() above

> +    # reduce queue count by 1
> +    expected = expected - 1

Verify first that queue count > 1. Which it isn't in the test setup.

> +    cmd(f"ethtool -L {cfg.dev['ifname']} combined {expected}")
> +    queues = nl_get_queues(cfg, nl)
> +    ksft_eq(queues, expected)
> +
> +    # increase queue count by 1
> +    expected = expected + 1
> +    cmd(f"ethtool -L {cfg.dev['ifname']} combined {expected}")
> +    queues = nl_get_queues(cfg, nl)
> +    ksft_eq(queues, expected)
> +
> +
> +def main() -> None:
> +    with NetDrvEnv(__file__, queue_count=3) as cfg:
> +        ksft_run([get_queues, addremove_queues], args=(cfg, NetdevFamily()))
> +
> +

Re: [PATCH net-next v2 2/2] net: selftest: add test for netdev netlink queue-get API

[David Wei]

On 2024-04-21 7:56 am, Willem de Bruijn wrote:
> David Wei wrote:
>> Add a selftest for netdev generic netlink. For now there is only a
>> single test that exercises the `queue-get` API.
>>
>> The test works with netdevsim by default or with a real device by
>> setting NETIF.
>>
>> Signed-off-by: David Wei <dw@davidwei.uk>
>> ---
>>  tools/testing/selftests/drivers/net/Makefile  |  1 +
>>  .../selftests/drivers/net/lib/py/env.py       |  6 +-
>>  tools/testing/selftests/drivers/net/queues.py | 59 +++++++++++++++++++
>>  tools/testing/selftests/net/lib/py/nsim.py    |  4 +-
>>  4 files changed, 66 insertions(+), 4 deletions(-)
>>  create mode 100755 tools/testing/selftests/drivers/net/queues.py
>>
>> diff --git a/tools/testing/selftests/drivers/net/Makefile b/tools/testing/selftests/drivers/net/Makefile
>> index 379cdb1960a7..118a73650dbc 100644
>> --- a/tools/testing/selftests/drivers/net/Makefile
>> +++ b/tools/testing/selftests/drivers/net/Makefile
>> @@ -3,5 +3,6 @@
>>  TEST_INCLUDES := $(wildcard lib/py/*.py)
>>  
>>  TEST_PROGS := stats.py
>> +TEST_PROGS += queues.py
>>  
>>  include ../../lib.mk
>> diff --git a/tools/testing/selftests/drivers/net/lib/py/env.py b/tools/testing/selftests/drivers/net/lib/py/env.py
>> index e1abe9491daf..0ac4e9e6cd84 100644
>> --- a/tools/testing/selftests/drivers/net/lib/py/env.py
>> +++ b/tools/testing/selftests/drivers/net/lib/py/env.py
>> @@ -7,7 +7,7 @@ from lib.py import ip
>>  from lib.py import NetdevSimDev
>>  
>>  class NetDrvEnv:
>> -    def __init__(self, src_path):
>> +    def __init__(self, src_path, **kwargs):
>>          self._ns = None
>>  
>>          self.env = os.environ.copy()
>> @@ -16,11 +16,13 @@ class NetDrvEnv:
>>          if 'NETIF' in self.env:
>>              self.dev = ip("link show dev " + self.env['NETIF'], json=True)[0]
>>          else:
>> -            self._ns = NetdevSimDev()
>> +            self._ns = NetdevSimDev(**kwargs)
>>              self.dev = self._ns.nsims[0].dev
>>          self.ifindex = self.dev['ifindex']
>>  
>>      def __enter__(self):
>> +        ip(f"link set dev {self.dev['ifname']} up")
>> +
>>          return self
>>  
>>      def __exit__(self, ex_type, ex_value, ex_tb):
>> diff --git a/tools/testing/selftests/drivers/net/queues.py b/tools/testing/selftests/drivers/net/queues.py
>> new file mode 100755
>> index 000000000000..c23cd5a932cb
>> --- /dev/null
>> +++ b/tools/testing/selftests/drivers/net/queues.py
>> @@ -0,0 +1,59 @@
>> +#!/usr/bin/env python3
>> +# SPDX-License-Identifier: GPL-2.0
>> +
>> +from lib.py import ksft_run, ksft_eq, KsftSkipEx
>> +from lib.py import NetdevFamily
>> +from lib.py import NetDrvEnv
>> +from lib.py import cmd
>> +import glob
>> +
>> +
>> +def sys_get_queues(ifname) -> int:
>> +    folders = glob.glob(f'/sys/class/net/{ifname}/queues/rx-*')
>> +    return len(folders)
>> +
>> +
>> +def nl_get_queues(cfg, nl):
>> +    queues = nl.queue_get({'ifindex': cfg.ifindex}, dump=True)
>> +    if queues:
>> +        return len([q for q in queues if q['type'] == 'rx'])
>> +    return None
>> +
>> +
>> +def get_queues(cfg, nl) -> None:
>> +    queues = nl_get_queues(cfg, nl)
>> +    if not queues:
>> +        raise KsftSkipEx("queue-get not supported by device")
>> +
>> +    expected = sys_get_queues(cfg.dev['ifname'])
>> +    ksft_eq(queues, expected)
>> +
>> +
>> +def addremove_queues(cfg, nl) -> None:
>> +    queues = nl_get_queues(cfg, nl)
>> +    if not queues:
>> +        raise KsftSkipEx("queue-get not supported by device")
>> +
>> +    expected = sys_get_queues(cfg.dev['ifname'])
>> +    ksft_eq(queues, expected)
>> +
> 
> This is a copy of get_queues() above

I'll remove this part of the test case.

> 
>> +    # reduce queue count by 1
>> +    expected = expected - 1
> 
> Verify first that queue count > 1. Which it isn't in the test setup.

Thanks, I'll make sure changing the queues for a real device doesn't go
out of bounds.

> 
>> +    cmd(f"ethtool -L {cfg.dev['ifname']} combined {expected}")
>> +    queues = nl_get_queues(cfg, nl)
>> +    ksft_eq(queues, expected)
>> +
>> +    # increase queue count by 1
>> +    expected = expected + 1
>> +    cmd(f"ethtool -L {cfg.dev['ifname']} combined {expected}")
>> +    queues = nl_get_queues(cfg, nl)
>> +    ksft_eq(queues, expected)
>> +
>> +
>> +def main() -> None:
>> +    with NetDrvEnv(__file__, queue_count=3) as cfg:
>> +        ksft_run([get_queues, addremove_queues], args=(cfg, NetdevFamily()))
>> +
>> +
> 
>