[PATCH net-next v16 00/12] vsock: add namespace support to vhost-vsock and loopback

[PATCH net-next v16 00/12] vsock: add namespace support to vhost-vsock and loopback

[Bobby Eshleman]

This series adds namespace support to vhost-vsock and loopback. It does
not add namespaces to any of the other guest transports (virtio-vsock,
hyperv, or vmci).

The current revision supports two modes: local and global. Local
mode is complete isolation of namespaces, while global mode is complete
sharing between namespaces of CIDs (the original behavior).

The mode is set using the parent namespace's
/proc/sys/net/vsock/child_ns_mode and inherited when a new namespace is
created. The mode of the current namespace can be queried by reading
/proc/sys/net/vsock/ns_mode. The mode can not change after the namespace
has been created.

Modes are per-netns. This allows a system to configure namespaces
independently (some may share CIDs, others are completely isolated).
This also supports future possible mixed use cases, where there may be
namespaces in global mode spinning up VMs while there are mixed mode
namespaces that provide services to the VMs, but are not allowed to
allocate from the global CID pool (this mode is not implemented in this
series).

Additionally, added tests for the new namespace features:

tools/testing/selftests/vsock/vmtest.sh
1..25
ok 1 vm_server_host_client
ok 2 vm_client_host_server
ok 3 vm_loopback
ok 4 ns_host_vsock_ns_mode_ok
ok 5 ns_host_vsock_child_ns_mode_ok
ok 6 ns_global_same_cid_fails
ok 7 ns_local_same_cid_ok
ok 8 ns_global_local_same_cid_ok
ok 9 ns_local_global_same_cid_ok
ok 10 ns_diff_global_host_connect_to_global_vm_ok
ok 11 ns_diff_global_host_connect_to_local_vm_fails
ok 12 ns_diff_global_vm_connect_to_global_host_ok
ok 13 ns_diff_global_vm_connect_to_local_host_fails
ok 14 ns_diff_local_host_connect_to_local_vm_fails
ok 15 ns_diff_local_vm_connect_to_local_host_fails
ok 16 ns_diff_global_to_local_loopback_local_fails
ok 17 ns_diff_local_to_global_loopback_fails
ok 18 ns_diff_local_to_local_loopback_fails
ok 19 ns_diff_global_to_global_loopback_ok
ok 20 ns_same_local_loopback_ok
ok 21 ns_same_local_host_connect_to_local_vm_ok
ok 22 ns_same_local_vm_connect_to_local_host_ok
ok 23 ns_delete_vm_ok
ok 24 ns_delete_host_ok
ok 25 ns_delete_both_ok
SUMMARY: PASS=25 SKIP=0 FAIL=0

Thanks again for everyone's help and reviews!

Suggested-by: Sargun Dhillon <sargun@sargun.me>
Signed-off-by: Bobby Eshleman <bobbyeshleman@gmail.com>

Changes in v16:
- updated comments/docs/commit msg (vsock_find_* funcs, init net
  mode, why change random port alloc)
- removed init ns mode cmdline
- fixed the missing ${ns} arg for vm_ssh in vmtest.sh
- Link to v15: https://lore.kernel.org/r/20260116-vsock-vmtest-v15-0-bbfd1a668548@meta.com

Changes in v15:
- see per-patch change notes in 'vsock: add netns to vsock core'
- Link to v14: https://lore.kernel.org/r/20260112-vsock-vmtest-v14-0-a5c332db3e2b@meta.com

Changes in v14:
- squashed 'vsock: add per-net vsock NS mode state' into 'vsock: add
  netns to vsock core' (MST)
- remove RFC tag
- fixed base-commit (still had b4 configured to depend on old vmtest.sh
  series)
- Link to v13: https://lore.kernel.org/all/20251223-vsock-vmtest-v13-0-9d6db8e7c80b@meta.com/

Changes in v13:
- add support for immutable sysfs ns_mode and inheritance from sysfs child_ns_mode
- remove passing around of net_mode, can be accessed now via
  vsock_net_mode(net) since it is immutable
- update tests for new uAPI
- add one patch to extend the kselftest timeout (it was starting to
  fail with the new tests added)
- Link to v12: https://lore.kernel.org/r/20251126-vsock-vmtest-v12-0-257ee21cd5de@meta.com

Changes in v12:
- add ns mode checking to _allow() callbacks to reject local mode for
  incompatible transports (Stefano)
- flip vhost/loopback to return true for stream_allow() and
  seqpacket_allow() in "vsock: add netns support to virtio transports"
  (Stefano)
- add VMADDR_CID_ANY + local mode documentation in af_vsock.c (Stefano)
- change "selftests/vsock: add tests for host <-> vm connectivity with
  namespaces" to skip test 29 in vsock_test for namespace local
  vsock_test calls in a host local-mode namespace. There is a
  false-positive edge case for that test encountered with the
  ->stream_allow() approach. More details in that patch.
- updated cover letter with new test output
- Link to v11: https://lore.kernel.org/r/20251120-vsock-vmtest-v11-0-55cbc80249a7@meta.com

Changes in v11:
- vmtest: add a patch to use ss in wait_for_listener functions and
  support vsock, tcp, and unix. Change all patches to use the new
  functions.
- vmtest: add a patch to re-use vm dmesg / warn counting functions
- Link to v10: https://lore.kernel.org/r/20251117-vsock-vmtest-v10-0-df08f165bf3e@meta.com

Changes in v10:
- Combine virtio common patches into one (Stefano)
- Resolve vsock_loopback virtio_transport_reset_no_sock() issue
  with info->vsk setting. This eliminates the need for skb->cb,
  so remove skb->cb patches.
- many line width 80 fixes
- Link to v9: https://lore.kernel.org/all/20251111-vsock-vmtest-v9-0-852787a37bed@meta.com

Changes in v9:
- reorder loopback patch after patch for virtio transport common code
- remove module ordering tests patch because loopback no longer depends
  on pernet ops
- major simplifications in vsock_loopback
- added a new patch for blocking local mode for guests, added test case
  to check
- add net ref tracking to vsock_loopback patch
- Link to v8: https://lore.kernel.org/r/20251023-vsock-vmtest-v8-0-dea984d02bb0@meta.com

Changes in v8:
- Break generic cleanup/refactoring patches into standalone series,
  remove those from this series
- Link to dependency: https://lore.kernel.org/all/20251022-vsock-selftests-fixes-and-improvements-v1-0-edeb179d6463@meta.com/
- Link to v7: https://lore.kernel.org/r/20251021-vsock-vmtest-v7-0-0661b7b6f081@meta.com

Changes in v7:
- fix hv_sock build
- break out vmtest patches into distinct, more well-scoped patches
- change `orig_net_mode` to `net_mode`
- many fixes and style changes in per-patch change sets (see individual
  patches for specific changes)
- optimize `virtio_vsock_skb_cb` layout
- update commit messages with more useful descriptions
- vsock_loopback: use orig_net_mode instead of current net mode
- add tests for edge cases (ns deletion, mode changing, loopback module
  load ordering)
- Link to v6: https://lore.kernel.org/r/20250916-vsock-vmtest-v6-0-064d2eb0c89d@meta.com

Changes in v6:
- define behavior when mode changes to local while socket/VM is alive
- af_vsock: clarify description of CID behavior
- af_vsock: use stronger langauge around CID rules (dont use "may")
- af_vsock: improve naming of buf/buffer
- af_vsock: improve string length checking on proc writes
- vsock_loopback: add space in struct to clarify lock protection
- vsock_loopback: do proper cleanup/unregister on vsock_loopback_exit()
- vsock_loopback: use virtio_vsock_skb_net() instead of sock_net()
- vsock_loopback: set loopback to NULL after kfree()
- vsock_loopback: use pernet_operations and remove callback mechanism
- vsock_loopback: add macros for "global" and "local"
- vsock_loopback: fix length checking
- vmtest.sh: check for namespace support in vmtest.sh
- Link to v5: https://lore.kernel.org/r/20250827-vsock-vmtest-v5-0-0ba580bede5b@meta.com

Changes in v5:
- /proc/net/vsock_ns_mode -> /proc/sys/net/vsock/ns_mode
- vsock_global_net -> vsock_global_dummy_net
- fix netns lookup in vhost_vsock to respect pid namespaces
- add callbacks for vsock_loopback to avoid circular dependency
- vmtest.sh loads vsock_loopback module
- remove vsock_net_mode_can_set()
- change vsock_net_write_mode() to return true/false based on success
- make vsock_net_mode enum instead of u8
- Link to v4: https://lore.kernel.org/r/20250805-vsock-vmtest-v4-0-059ec51ab111@meta.com

Changes in v4:
- removed RFC tag
- implemented loopback support
- renamed new tests to better reflect behavior
- completed suite of tests with permutations of ns modes and vsock_test
  as guest/host
- simplified socat bridging with unix socket instead of tcp + veth
- only use vsock_test for success case, socat for failure case (context
  in commit message)
- lots of cleanup

Changes in v3:
- add notion of "modes"
- add procfs /proc/net/vsock_ns_mode
- local and global modes only
- no /dev/vhost-vsock-netns
- vmtest.sh already merged, so new patch just adds new tests for NS
- Link to v2:
  https://lore.kernel.org/kvm/20250312-vsock-netns-v2-0-84bffa1aa97a@gmail.com

Changes in v2:
- only support vhost-vsock namespaces
- all g2h namespaces retain old behavior, only common API changes
  impacted by vhost-vsock changes
- add /dev/vhost-vsock-netns for "opt-in"
- leave /dev/vhost-vsock to old behavior
- removed netns module param
- Link to v1:
  https://lore.kernel.org/r/20200116172428.311437-1-sgarzare@redhat.com

Changes in v1:
- added 'netns' module param to vsock.ko to enable the
  network namespace support (disabled by default)
- added 'vsock_net_eq()' to check the "net" assigned to a socket
  only when 'netns' support is enabled
- Link to RFC: https://patchwork.ozlabs.org/cover/1202235/

---
Bobby Eshleman (12):
      vsock: add netns to vsock core
      virtio: set skb owner of virtio_transport_reset_no_sock() reply
      vsock: add netns support to virtio transports
      selftests/vsock: increase timeout to 1200
      selftests/vsock: add namespace helpers to vmtest.sh
      selftests/vsock: prepare vm management helpers for namespaces
      selftests/vsock: add vm_dmesg_{warn,oops}_count() helpers
      selftests/vsock: use ss to wait for listeners instead of /proc/net
      selftests/vsock: add tests for proc sys vsock ns_mode
      selftests/vsock: add namespace tests for CID collisions
      selftests/vsock: add tests for host <-> vm connectivity with namespaces
      selftests/vsock: add tests for namespace deletion

 MAINTAINERS                             |    1 +
 drivers/vhost/vsock.c                   |   44 +-
 include/linux/virtio_vsock.h            |    9 +-
 include/net/af_vsock.h                  |   61 +-
 include/net/net_namespace.h             |    4 +
 include/net/netns/vsock.h               |   21 +
 net/vmw_vsock/af_vsock.c                |  335 +++++++++-
 net/vmw_vsock/hyperv_transport.c        |    7 +-
 net/vmw_vsock/virtio_transport.c        |   22 +-
 net/vmw_vsock/virtio_transport_common.c |   62 +-
 net/vmw_vsock/vmci_transport.c          |   26 +-
 net/vmw_vsock/vsock_loopback.c          |   22 +-
 tools/testing/selftests/vsock/settings  |    2 +-
 tools/testing/selftests/vsock/vmtest.sh | 1055 +++++++++++++++++++++++++++++--
 14 files changed, 1531 insertions(+), 140 deletions(-)
---
base-commit: d8f87aa5fa0a4276491fa8ef436cd22605a3f9ba
change-id: 20250325-vsock-vmtest-b3a21d2102c2

Best regards,
-- 
Bobby Eshleman <bobbyeshleman@meta.com>

[PATCH net-next v16 01/12] vsock: add netns to vsock core

[Bobby Eshleman]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Add netns logic to vsock core. Additionally, modify transport hook
prototypes to be used by later transport-specific patches (e.g.,
*_seqpacket_allow()).

Namespaces are supported primarily by changing socket lookup functions
(e.g., vsock_find_connected_socket()) to take into account the socket
namespace and the namespace mode before considering a candidate socket a
"match".

This patch also introduces the sysctl /proc/sys/net/vsock/ns_mode to
report the mode and /proc/sys/net/vsock/child_ns_mode to set the mode
for new namespaces.

Add netns functionality (initialization, passing to transports, procfs,
etc...) to the af_vsock socket layer. Later patches that add netns
support to transports depend on this patch.

This patch changes the allocation of random ports for connectible vsocks
in order to avoid leaking the random port range starting point to other
namespaces.

dgram_allow(), stream_allow(), and seqpacket_allow() callbacks are
modified to take a vsk in order to perform logic on namespace modes. In
future patches, the net will also be used for socket
lookups in these functions.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
Changes in v16:
- remove vsock_init_ns_mode kernel cmdline
- add documentation at top of af_vsock.c about init_net being global
  and unmodifiable
- add comments for vsock_find* and vsock_find*_net functions to clarify
  which to choose for which transports

Changes in v15:
- make static port in __vsock_bind_connectible per-netns
- remove __net_initdata because we want the ops beyond just boot
- add vsock_init_ns_mode kernel cmdline parameter to set init ns mode
- use if (ret || !write) in __vsock_net_mode_string() (Stefano)
- add vsock_net_mode_global() (Stefano)
- hide !net == VSOCK_NET_MODE_GLOBAL inside vsock_net_mode() (Stefano)
- clarify af_vsock.c comments on ns_mode/child_ns_mode (Stefano)

Changes in v14:
- include linux/sysctl.h in af_vsock.c
- squash patch 'vsock: add per-net vsock NS mode state' into this patch
  (prior version can be found here):
  https://lore.kernel.org/all/20251223-vsock-vmtest-v13-1-9d6db8e7c80b@meta.com/)

Changes in v13:
- remove net_mode and replace with direct accesses to net->vsock.mode,
  since this is now immutable.
- update comments about mode behavior and mutability, and sysctl API
- only pass NULL for net when wanting global, instead of net_mode ==
  VSOCK_NET_MODE_GLOBAL. This reflects the new logic
  of vsock_net_check_mode() that only requires net pointers (not
  net_mode).
- refactor sysctl string code into a re-usable function, because
  child_ns_mode and ns_mode both handle the same strings.
- remove redundant vsock_net_init(&init_net) call in module init because
  pernet registration calls the callback on the init_net too

Changes in v12:
- return true in dgram_allow(), stream_allow(), and seqpacket_allow()
  only if net_mode == VSOCK_NET_MODE_GLOBAL (Stefano)
- document bind(VMADDR_CID_ANY) case in af_vsock.c (Stefano)
- change order of stream_allow() call in vmci so we can pass vsk
  to it

Changes in v10:
- add file-level comment about what happens to sockets/devices
  when the namespace mode changes (Stefano)
- change the 'if (write)' boolean in vsock_net_mode_string() to
  if (!write), this simplifies a later patch which adds "goto"
  for mutex unlocking on function exit.

Changes in v9:
- remove virtio_vsock_alloc_rx_skb() (Stefano)
- remove vsock_global_dummy_net, not needed as net=NULL +
  net_mode=VSOCK_NET_MODE_GLOBAL achieves identical result

Changes in v7:
- hv_sock: fix hyperv build error
- explain why vhost does not use the dummy
- explain usage of __vsock_global_dummy_net
- explain why VSOCK_NET_MODE_STR_MAX is 8 characters
- use switch-case in vsock_net_mode_string()
- avoid changing transports as much as possible
- add vsock_find_{bound,connected}_socket_net()
- rename `vsock_hdr` to `sysctl_hdr`
- add virtio_vsock_alloc_linear_skb() wrapper for setting dummy net and
  global mode for virtio-vsock, move skb->cb zero-ing into wrapper
- explain seqpacket_allow() change
- move net setting to __vsock_create() instead of vsock_create() so
  that child sockets also have their net assigned upon accept()

Changes in v6:
- unregister sysctl ops in vsock_exit()
- af_vsock: clarify description of CID behavior
- af_vsock: fix buf vs buffer naming, and length checking
- af_vsock: fix length checking w/ correct ctl_table->maxlen

Changes in v5:
- vsock_global_net() -> vsock_global_dummy_net()
- update comments for new uAPI
- use /proc/sys/net/vsock/ns_mode instead of /proc/net/vsock_ns_mode
- add prototype changes so patch remains compilable
---
 MAINTAINERS                             |   1 +
 drivers/vhost/vsock.c                   |   6 +-
 include/linux/virtio_vsock.h            |   4 +-
 include/net/af_vsock.h                  |  61 +++++-
 include/net/net_namespace.h             |   4 +
 include/net/netns/vsock.h               |  21 ++
 net/vmw_vsock/af_vsock.c                | 335 +++++++++++++++++++++++++++++---
 net/vmw_vsock/hyperv_transport.c        |   7 +-
 net/vmw_vsock/virtio_transport.c        |   9 +-
 net/vmw_vsock/virtio_transport_common.c |   6 +-
 net/vmw_vsock/vmci_transport.c          |  26 ++-
 net/vmw_vsock/vsock_loopback.c          |   8 +-
 12 files changed, 437 insertions(+), 51 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 92768bceb929..8341a451570b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -27549,6 +27549,7 @@ L:	netdev@vger.kernel.org
 S:	Maintained
 F:	drivers/vhost/vsock.c
 F:	include/linux/virtio_vsock.h
+F:	include/net/netns/vsock.h
 F:	include/uapi/linux/virtio_vsock.h
 F:	net/vmw_vsock/virtio_transport.c
 F:	net/vmw_vsock/virtio_transport_common.c
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 552cfb53498a..647ded6f6ea5 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -407,7 +407,8 @@ static bool vhost_transport_msgzerocopy_allow(void)
 	return true;
 }
 
-static bool vhost_transport_seqpacket_allow(u32 remote_cid);
+static bool vhost_transport_seqpacket_allow(struct vsock_sock *vsk,
+					    u32 remote_cid);
 
 static struct virtio_transport vhost_transport = {
 	.transport = {
@@ -463,7 +464,8 @@ static struct virtio_transport vhost_transport = {
 	.send_pkt = vhost_transport_send_pkt,
 };
 
-static bool vhost_transport_seqpacket_allow(u32 remote_cid)
+static bool vhost_transport_seqpacket_allow(struct vsock_sock *vsk,
+					    u32 remote_cid)
 {
 	struct vhost_vsock *vsock;
 	bool seqpacket_allow = false;
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index 0c67543a45c8..1845e8d4f78d 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h
@@ -256,10 +256,10 @@ void virtio_transport_notify_buffer_size(struct vsock_sock *vsk, u64 *val);
 
 u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk);
 bool virtio_transport_stream_is_active(struct vsock_sock *vsk);
-bool virtio_transport_stream_allow(u32 cid, u32 port);
+bool virtio_transport_stream_allow(struct vsock_sock *vsk, u32 cid, u32 port);
 int virtio_transport_dgram_bind(struct vsock_sock *vsk,
 				struct sockaddr_vm *addr);
-bool virtio_transport_dgram_allow(u32 cid, u32 port);
+bool virtio_transport_dgram_allow(struct vsock_sock *vsk, u32 cid, u32 port);
 
 int virtio_transport_connect(struct vsock_sock *vsk);
 
diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index d40e978126e3..d3ff48a2fbe0 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -10,6 +10,7 @@
 
 #include <linux/kernel.h>
 #include <linux/workqueue.h>
+#include <net/netns/vsock.h>
 #include <net/sock.h>
 #include <uapi/linux/vm_sockets.h>
 
@@ -124,7 +125,7 @@ struct vsock_transport {
 			     size_t len, int flags);
 	int (*dgram_enqueue)(struct vsock_sock *, struct sockaddr_vm *,
 			     struct msghdr *, size_t len);
-	bool (*dgram_allow)(u32 cid, u32 port);
+	bool (*dgram_allow)(struct vsock_sock *vsk, u32 cid, u32 port);
 
 	/* STREAM. */
 	/* TODO: stream_bind() */
@@ -136,14 +137,14 @@ struct vsock_transport {
 	s64 (*stream_has_space)(struct vsock_sock *);
 	u64 (*stream_rcvhiwat)(struct vsock_sock *);
 	bool (*stream_is_active)(struct vsock_sock *);
-	bool (*stream_allow)(u32 cid, u32 port);
+	bool (*stream_allow)(struct vsock_sock *vsk, u32 cid, u32 port);
 
 	/* SEQ_PACKET. */
 	ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
 				     int flags);
 	int (*seqpacket_enqueue)(struct vsock_sock *vsk, struct msghdr *msg,
 				 size_t len);
-	bool (*seqpacket_allow)(u32 remote_cid);
+	bool (*seqpacket_allow)(struct vsock_sock *vsk, u32 remote_cid);
 	u32 (*seqpacket_has_data)(struct vsock_sock *vsk);
 
 	/* Notification. */
@@ -216,6 +217,11 @@ void vsock_remove_connected(struct vsock_sock *vsk);
 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr);
 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
 					 struct sockaddr_vm *dst);
+struct sock *vsock_find_bound_socket_net(struct sockaddr_vm *addr,
+					 struct net *net);
+struct sock *vsock_find_connected_socket_net(struct sockaddr_vm *src,
+					     struct sockaddr_vm *dst,
+					     struct net *net);
 void vsock_remove_sock(struct vsock_sock *vsk);
 void vsock_for_each_connected_socket(struct vsock_transport *transport,
 				     void (*fn)(struct sock *sk));
@@ -256,4 +262,53 @@ static inline bool vsock_msgzerocopy_allow(const struct vsock_transport *t)
 {
 	return t->msgzerocopy_allow && t->msgzerocopy_allow();
 }
+
+static inline enum vsock_net_mode vsock_net_mode(struct net *net)
+{
+	if (!net)
+		return VSOCK_NET_MODE_GLOBAL;
+
+	return READ_ONCE(net->vsock.mode);
+}
+
+static inline bool vsock_net_mode_global(struct vsock_sock *vsk)
+{
+	return vsock_net_mode(sock_net(sk_vsock(vsk))) == VSOCK_NET_MODE_GLOBAL;
+}
+
+static inline void vsock_net_set_child_mode(struct net *net,
+					    enum vsock_net_mode mode)
+{
+	WRITE_ONCE(net->vsock.child_ns_mode, mode);
+}
+
+static inline enum vsock_net_mode vsock_net_child_mode(struct net *net)
+{
+	return READ_ONCE(net->vsock.child_ns_mode);
+}
+
+/* Return true if two namespaces pass the mode rules. Otherwise, return false.
+ *
+ * A NULL namespace is treated as VSOCK_NET_MODE_GLOBAL.
+ *
+ * Read more about modes in the comment header of net/vmw_vsock/af_vsock.c.
+ */
+static inline bool vsock_net_check_mode(struct net *ns0, struct net *ns1)
+{
+	enum vsock_net_mode mode0, mode1;
+
+	/* Any vsocks within the same network namespace are always reachable,
+	 * regardless of the mode.
+	 */
+	if (net_eq(ns0, ns1))
+		return true;
+
+	mode0 = vsock_net_mode(ns0);
+	mode1 = vsock_net_mode(ns1);
+
+	/* Different namespaces are only reachable if they are both
+	 * global mode.
+	 */
+	return mode0 == VSOCK_NET_MODE_GLOBAL && mode0 == mode1;
+}
 #endif /* __AF_VSOCK_H__ */
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index cb664f6e3558..66d3de1d935f 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -37,6 +37,7 @@
 #include <net/netns/smc.h>
 #include <net/netns/bpf.h>
 #include <net/netns/mctp.h>
+#include <net/netns/vsock.h>
 #include <net/net_trackers.h>
 #include <linux/ns_common.h>
 #include <linux/idr.h>
@@ -196,6 +197,9 @@ struct net {
 	/* Move to a better place when the config guard is removed. */
 	struct mutex		rtnl_mutex;
 #endif
+#if IS_ENABLED(CONFIG_VSOCKETS)
+	struct netns_vsock	vsock;
+#endif
 } __randomize_layout;
 
 #include <linux/seq_file_net.h>
diff --git a/include/net/netns/vsock.h b/include/net/netns/vsock.h
new file mode 100644
index 000000000000..b34d69a22fa8
--- /dev/null
+++ b/include/net/netns/vsock.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NET_NET_NAMESPACE_VSOCK_H
+#define __NET_NET_NAMESPACE_VSOCK_H
+
+#include <linux/types.h>
+
+enum vsock_net_mode {
+	VSOCK_NET_MODE_GLOBAL,
+	VSOCK_NET_MODE_LOCAL,
+};
+
+struct netns_vsock {
+	struct ctl_table_header *sysctl_hdr;
+
+	/* protected by the vsock_table_lock in af_vsock.c */
+	u32 port;
+
+	enum vsock_net_mode mode;
+	enum vsock_net_mode child_ns_mode;
+};
+#endif /* __NET_NET_NAMESPACE_VSOCK_H */
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index a3505a4dcee0..20ad2b2dc17b 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -83,6 +83,50 @@
  *   TCP_ESTABLISHED - connected
  *   TCP_CLOSING - disconnecting
  *   TCP_LISTEN - listening
+ *
+ * - Namespaces in vsock support two different modes: "local" and "global".
+ *   Each mode defines how the namespace interacts with CIDs.
+ *   Each namespace exposes two sysctl files:
+ *
+ *   - /proc/sys/net/vsock/ns_mode (read-only) reports the current namespace's
+ *     mode, which is set at namespace creation and immutable thereafter.
+ *   - /proc/sys/net/vsock/child_ns_mode (writable) controls what mode future
+ *     child namespaces will inherit when created. The default is "global".
+ *
+ *   Changing child_ns_mode only affects newly created namespaces, not the
+ *   current namespace or existing children. At namespace creation, ns_mode
+ *   is inherited from the parent's child_ns_mode.
+ *
+ *   The init_net mode is "global" and cannot be modified.
+ *
+ *   The modes affect the allocation and accessibility of CIDs as follows:
+ *
+ *   - global - access and allocation are all system-wide
+ *      - all CID allocation from global namespaces draw from the same
+ *        system-wide pool.
+ *      - if one global namespace has already allocated some CID, another
+ *        global namespace will not be able to allocate the same CID.
+ *      - global mode AF_VSOCK sockets can reach any VM or socket in any global
+ *        namespace, they are not contained to only their own namespace.
+ *      - AF_VSOCK sockets in a global mode namespace cannot reach VMs or
+ *        sockets in any local mode namespace.
+ *   - local - access and allocation are contained within the namespace
+ *     - CID allocation draws only from a private pool local only to the
+ *       namespace, and does not affect the CIDs available for allocation in any
+ *       other namespace (global or local).
+ *     - VMs in a local namespace do not collide with CIDs in any other local
+ *       namespace or any global namespace. For example, if a VM in a local mode
+ *       namespace is given CID 10, then CID 10 is still available for
+ *       allocation in any other namespace, but not in the same namespace.
+ *     - AF_VSOCK sockets in a local mode namespace can connect only to VMs or
+ *       other sockets within their own namespace.
+ *     - sockets bound to VMADDR_CID_ANY in local namespaces will never resolve
+ *       to any transport that is not compatible with local mode. There is no
+ *       error that propagates to the user (as there is for connection attempts)
+ *       because it is possible for some packet to reach this socket from
+ *       a different transport that *does* support local mode. For
+ *       example, virtio-vsock may not support local mode, but the socket
+ *       may still accept a connection from vhost-vsock which does.
  */
 
 #include <linux/compat.h>
@@ -100,20 +144,31 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/net.h>
+#include <linux/proc_fs.h>
 #include <linux/poll.h>
 #include <linux/random.h>
 #include <linux/skbuff.h>
 #include <linux/smp.h>
 #include <linux/socket.h>
 #include <linux/stddef.h>
+#include <linux/sysctl.h>
 #include <linux/unistd.h>
 #include <linux/wait.h>
 #include <linux/workqueue.h>
 #include <net/sock.h>
 #include <net/af_vsock.h>
+#include <net/netns/vsock.h>
 #include <uapi/linux/vm_sockets.h>
 #include <uapi/asm-generic/ioctls.h>
 
+#define VSOCK_NET_MODE_STR_GLOBAL "global"
+#define VSOCK_NET_MODE_STR_LOCAL "local"
+
+/* 6 chars for "global", 1 for null-terminator, and 1 more for '\n'.
+ * The newline is added by proc_dostring() for read operations.
+ */
+#define VSOCK_NET_MODE_STR_MAX 8
+
 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
 static void vsock_sk_destruct(struct sock *sk);
 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
@@ -235,33 +290,42 @@ static void __vsock_remove_connected(struct vsock_sock *vsk)
 	sock_put(&vsk->sk);
 }
 
-static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
+static struct sock *__vsock_find_bound_socket_net(struct sockaddr_vm *addr,
+						  struct net *net)
 {
 	struct vsock_sock *vsk;
 
 	list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
-		if (vsock_addr_equals_addr(addr, &vsk->local_addr))
-			return sk_vsock(vsk);
+		struct sock *sk = sk_vsock(vsk);
+
+		if (vsock_addr_equals_addr(addr, &vsk->local_addr) &&
+		    vsock_net_check_mode(sock_net(sk), net))
+			return sk;
 
 		if (addr->svm_port == vsk->local_addr.svm_port &&
 		    (vsk->local_addr.svm_cid == VMADDR_CID_ANY ||
-		     addr->svm_cid == VMADDR_CID_ANY))
-			return sk_vsock(vsk);
+		     addr->svm_cid == VMADDR_CID_ANY) &&
+		     vsock_net_check_mode(sock_net(sk), net))
+			return sk;
 	}
 
 	return NULL;
 }
 
-static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
-						  struct sockaddr_vm *dst)
+static struct sock *
+__vsock_find_connected_socket_net(struct sockaddr_vm *src,
+				  struct sockaddr_vm *dst, struct net *net)
 {
 	struct vsock_sock *vsk;
 
 	list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
 			    connected_table) {
+		struct sock *sk = sk_vsock(vsk);
+
 		if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
-		    dst->svm_port == vsk->local_addr.svm_port) {
-			return sk_vsock(vsk);
+		    dst->svm_port == vsk->local_addr.svm_port &&
+		    vsock_net_check_mode(sock_net(sk), net)) {
+			return sk;
 		}
 	}
 
@@ -304,12 +368,18 @@ void vsock_remove_connected(struct vsock_sock *vsk)
 }
 EXPORT_SYMBOL_GPL(vsock_remove_connected);
 
-struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
+/* Find a bound socket, filtering by namespace and namespace mode.
+ *
+ * Use this in transports that are namespace-aware and can provide the
+ * network namespace context.
+ */
+struct sock *vsock_find_bound_socket_net(struct sockaddr_vm *addr,
+					 struct net *net)
 {
 	struct sock *sk;
 
 	spin_lock_bh(&vsock_table_lock);
-	sk = __vsock_find_bound_socket(addr);
+	sk = __vsock_find_bound_socket_net(addr, net);
 	if (sk)
 		sock_hold(sk);
 
@@ -317,15 +387,32 @@ struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
 
 	return sk;
 }
+EXPORT_SYMBOL_GPL(vsock_find_bound_socket_net);
+
+/* Find a bound socket without namespace filtering.
+ *
+ * Use this in transports that lack namespace context. All sockets are
+ * treated as if in global mode.
+ */
+struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
+{
+	return vsock_find_bound_socket_net(addr, NULL);
+}
 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
 
-struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
-					 struct sockaddr_vm *dst)
+/* Find a connected socket, filtering by namespace and namespace mode.
+ *
+ * Use this in transports that are namespace-aware and can provide the
+ * network namespace context.
+ */
+struct sock *vsock_find_connected_socket_net(struct sockaddr_vm *src,
+					     struct sockaddr_vm *dst,
+					     struct net *net)
 {
 	struct sock *sk;
 
 	spin_lock_bh(&vsock_table_lock);
-	sk = __vsock_find_connected_socket(src, dst);
+	sk = __vsock_find_connected_socket_net(src, dst, net);
 	if (sk)
 		sock_hold(sk);
 
@@ -333,6 +420,18 @@ struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
 
 	return sk;
 }
+EXPORT_SYMBOL_GPL(vsock_find_connected_socket_net);
+
+/* Find a connected socket without namespace filtering.
+ *
+ * Use this in transports that lack namespace context. All sockets are
+ * treated as if in global mode.
+ */
+struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
+					 struct sockaddr_vm *dst)
+{
+	return vsock_find_connected_socket_net(src, dst, NULL);
+}
 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
 
 void vsock_remove_sock(struct vsock_sock *vsk)
@@ -528,7 +627,7 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 
 	if (sk->sk_type == SOCK_SEQPACKET) {
 		if (!new_transport->seqpacket_allow ||
-		    !new_transport->seqpacket_allow(remote_cid)) {
+		    !new_transport->seqpacket_allow(vsk, remote_cid)) {
 			module_put(new_transport->module);
 			return -ESOCKTNOSUPPORT;
 		}
@@ -676,11 +775,11 @@ static void vsock_pending_work(struct work_struct *work)
 static int __vsock_bind_connectible(struct vsock_sock *vsk,
 				    struct sockaddr_vm *addr)
 {
-	static u32 port;
+	struct net *net = sock_net(sk_vsock(vsk));
 	struct sockaddr_vm new_addr;
 
-	if (!port)
-		port = get_random_u32_above(LAST_RESERVED_PORT);
+	if (!net->vsock.port)
+		net->vsock.port = get_random_u32_above(LAST_RESERVED_PORT);
 
 	vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
 
@@ -689,13 +788,13 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
 		unsigned int i;
 
 		for (i = 0; i < MAX_PORT_RETRIES; i++) {
-			if (port == VMADDR_PORT_ANY ||
-			    port <= LAST_RESERVED_PORT)
-				port = LAST_RESERVED_PORT + 1;
+			if (net->vsock.port == VMADDR_PORT_ANY ||
+			    net->vsock.port <= LAST_RESERVED_PORT)
+				net->vsock.port = LAST_RESERVED_PORT + 1;
 
-			new_addr.svm_port = port++;
+			new_addr.svm_port = net->vsock.port++;
 
-			if (!__vsock_find_bound_socket(&new_addr)) {
+			if (!__vsock_find_bound_socket_net(&new_addr, net)) {
 				found = true;
 				break;
 			}
@@ -712,7 +811,7 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
 			return -EACCES;
 		}
 
-		if (__vsock_find_bound_socket(&new_addr))
+		if (__vsock_find_bound_socket_net(&new_addr, net))
 			return -EADDRINUSE;
 	}
 
@@ -1314,7 +1413,7 @@ static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
 		goto out;
 	}
 
-	if (!transport->dgram_allow(remote_addr->svm_cid,
+	if (!transport->dgram_allow(vsk, remote_addr->svm_cid,
 				    remote_addr->svm_port)) {
 		err = -EINVAL;
 		goto out;
@@ -1355,7 +1454,7 @@ static int vsock_dgram_connect(struct socket *sock,
 	if (err)
 		goto out;
 
-	if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
+	if (!vsk->transport->dgram_allow(vsk, remote_addr->svm_cid,
 					 remote_addr->svm_port)) {
 		err = -EINVAL;
 		goto out;
@@ -1585,7 +1684,7 @@ static int vsock_connect(struct socket *sock, struct sockaddr_unsized *addr,
 		 * endpoints.
 		 */
 		if (!transport ||
-		    !transport->stream_allow(remote_addr->svm_cid,
+		    !transport->stream_allow(vsk, remote_addr->svm_cid,
 					     remote_addr->svm_port)) {
 			err = -ENETUNREACH;
 			goto out;
@@ -2662,6 +2761,180 @@ static struct miscdevice vsock_device = {
 	.fops		= &vsock_device_ops,
 };
 
+static int __vsock_net_mode_string(const struct ctl_table *table, int write,
+				   void *buffer, size_t *lenp, loff_t *ppos,
+				   enum vsock_net_mode mode,
+				   enum vsock_net_mode *new_mode)
+{
+	char data[VSOCK_NET_MODE_STR_MAX] = {0};
+	struct ctl_table tmp;
+	int ret;
+
+	if (!table->data || !table->maxlen || !*lenp) {
+		*lenp = 0;
+		return 0;
+	}
+
+	tmp = *table;
+	tmp.data = data;
+
+	if (!write) {
+		const char *p;
+
+		switch (mode) {
+		case VSOCK_NET_MODE_GLOBAL:
+			p = VSOCK_NET_MODE_STR_GLOBAL;
+			break;
+		case VSOCK_NET_MODE_LOCAL:
+			p = VSOCK_NET_MODE_STR_LOCAL;
+			break;
+		default:
+			WARN_ONCE(true, "netns has invalid vsock mode");
+			*lenp = 0;
+			return 0;
+		}
+
+		strscpy(data, p, sizeof(data));
+		tmp.maxlen = strlen(p);
+	}
+
+	ret = proc_dostring(&tmp, write, buffer, lenp, ppos);
+	if (ret || !write)
+		return ret;
+
+	if (*lenp >= sizeof(data))
+		return -EINVAL;
+
+	if (!strncmp(data, VSOCK_NET_MODE_STR_GLOBAL, sizeof(data)))
+		*new_mode = VSOCK_NET_MODE_GLOBAL;
+	else if (!strncmp(data, VSOCK_NET_MODE_STR_LOCAL, sizeof(data)))
+		*new_mode = VSOCK_NET_MODE_LOCAL;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+static int vsock_net_mode_string(const struct ctl_table *table, int write,
+				 void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct net *net;
+
+	if (write)
+		return -EPERM;
+
+	net = current->nsproxy->net_ns;
+
+	return __vsock_net_mode_string(table, write, buffer, lenp, ppos,
+				       vsock_net_mode(net), NULL);
+}
+
+static int vsock_net_child_mode_string(const struct ctl_table *table, int write,
+				       void *buffer, size_t *lenp, loff_t *ppos)
+{
+	enum vsock_net_mode new_mode;
+	struct net *net;
+	int ret;
+
+	net = current->nsproxy->net_ns;
+
+	ret = __vsock_net_mode_string(table, write, buffer, lenp, ppos,
+				      vsock_net_child_mode(net), &new_mode);
+	if (ret)
+		return ret;
+
+	if (write)
+		vsock_net_set_child_mode(net, new_mode);
+
+	return 0;
+}
+
+static struct ctl_table vsock_table[] = {
+	{
+		.procname	= "ns_mode",
+		.data		= &init_net.vsock.mode,
+		.maxlen		= VSOCK_NET_MODE_STR_MAX,
+		.mode		= 0444,
+		.proc_handler	= vsock_net_mode_string
+	},
+	{
+		.procname	= "child_ns_mode",
+		.data		= &init_net.vsock.child_ns_mode,
+		.maxlen		= VSOCK_NET_MODE_STR_MAX,
+		.mode		= 0644,
+		.proc_handler	= vsock_net_child_mode_string
+	},
+};
+
+static int __net_init vsock_sysctl_register(struct net *net)
+{
+	struct ctl_table *table;
+
+	if (net_eq(net, &init_net)) {
+		table = vsock_table;
+	} else {
+		table = kmemdup(vsock_table, sizeof(vsock_table), GFP_KERNEL);
+		if (!table)
+			goto err_alloc;
+
+		table[0].data = &net->vsock.mode;
+		table[1].data = &net->vsock.child_ns_mode;
+	}
+
+	net->vsock.sysctl_hdr = register_net_sysctl_sz(net, "net/vsock", table,
+						       ARRAY_SIZE(vsock_table));
+	if (!net->vsock.sysctl_hdr)
+		goto err_reg;
+
+	return 0;
+
+err_reg:
+	if (!net_eq(net, &init_net))
+		kfree(table);
+err_alloc:
+	return -ENOMEM;
+}
+
+static void vsock_sysctl_unregister(struct net *net)
+{
+	const struct ctl_table *table;
+
+	table = net->vsock.sysctl_hdr->ctl_table_arg;
+	unregister_net_sysctl_table(net->vsock.sysctl_hdr);
+	if (!net_eq(net, &init_net))
+		kfree(table);
+}
+
+static void vsock_net_init(struct net *net)
+{
+	if (net_eq(net, &init_net))
+		net->vsock.mode = VSOCK_NET_MODE_GLOBAL;
+	else
+		net->vsock.mode = vsock_net_child_mode(current->nsproxy->net_ns);
+
+	net->vsock.child_ns_mode = VSOCK_NET_MODE_GLOBAL;
+}
+
+static __net_init int vsock_sysctl_init_net(struct net *net)
+{
+	vsock_net_init(net);
+
+	if (vsock_sysctl_register(net))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static __net_exit void vsock_sysctl_exit_net(struct net *net)
+{
+	vsock_sysctl_unregister(net);
+}
+
+static struct pernet_operations vsock_sysctl_ops = {
+	.init = vsock_sysctl_init_net,
+	.exit = vsock_sysctl_exit_net,
+};
+
 static int __init vsock_init(void)
 {
 	int err = 0;
@@ -2689,10 +2962,17 @@ static int __init vsock_init(void)
 		goto err_unregister_proto;
 	}
 
+	if (register_pernet_subsys(&vsock_sysctl_ops)) {
+		err = -ENOMEM;
+		goto err_unregister_sock;
+	}
+
 	vsock_bpf_build_proto();
 
 	return 0;
 
+err_unregister_sock:
+	sock_unregister(AF_VSOCK);
 err_unregister_proto:
 	proto_unregister(&vsock_proto);
 err_deregister_misc:
@@ -2706,6 +2986,7 @@ static void __exit vsock_exit(void)
 	misc_deregister(&vsock_device);
 	sock_unregister(AF_VSOCK);
 	proto_unregister(&vsock_proto);
+	unregister_pernet_subsys(&vsock_sysctl_ops);
 }
 
 const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index 432fcbbd14d4..c3010c874308 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -570,7 +570,7 @@ static int hvs_dgram_enqueue(struct vsock_sock *vsk,
 	return -EOPNOTSUPP;
 }
 
-static bool hvs_dgram_allow(u32 cid, u32 port)
+static bool hvs_dgram_allow(struct vsock_sock *vsk, u32 cid, u32 port)
 {
 	return false;
 }
@@ -745,8 +745,11 @@ static bool hvs_stream_is_active(struct vsock_sock *vsk)
 	return hvs->chan != NULL;
 }
 
-static bool hvs_stream_allow(u32 cid, u32 port)
+static bool hvs_stream_allow(struct vsock_sock *vsk, u32 cid, u32 port)
 {
+	if (!vsock_net_mode_global(vsk))
+		return false;
+
 	if (cid == VMADDR_CID_HOST)
 		return true;
 
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 8c867023a2e5..f0a9e51118f3 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -536,7 +536,8 @@ static bool virtio_transport_msgzerocopy_allow(void)
 	return true;
 }
 
-static bool virtio_transport_seqpacket_allow(u32 remote_cid);
+static bool virtio_transport_seqpacket_allow(struct vsock_sock *vsk,
+					     u32 remote_cid);
 
 static struct virtio_transport virtio_transport = {
 	.transport = {
@@ -593,11 +594,15 @@ static struct virtio_transport virtio_transport = {
 	.can_msgzerocopy = virtio_transport_can_msgzerocopy,
 };
 
-static bool virtio_transport_seqpacket_allow(u32 remote_cid)
+static bool
+virtio_transport_seqpacket_allow(struct vsock_sock *vsk, u32 remote_cid)
 {
 	struct virtio_vsock *vsock;
 	bool seqpacket_allow;
 
+	if (!vsock_net_mode_global(vsk))
+		return false;
+
 	seqpacket_allow = false;
 	rcu_read_lock();
 	vsock = rcu_dereference(the_virtio_vsock);
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index dcc8a1d5851e..fdb8f5b3fa60 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1043,9 +1043,9 @@ bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
 }
 EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
 
-bool virtio_transport_stream_allow(u32 cid, u32 port)
+bool virtio_transport_stream_allow(struct vsock_sock *vsk, u32 cid, u32 port)
 {
-	return true;
+	return vsock_net_mode(sock_net(sk_vsock(vsk))) == VSOCK_NET_MODE_GLOBAL;
 }
 EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
 
@@ -1056,7 +1056,7 @@ int virtio_transport_dgram_bind(struct vsock_sock *vsk,
 }
 EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
 
-bool virtio_transport_dgram_allow(u32 cid, u32 port)
+bool virtio_transport_dgram_allow(struct vsock_sock *vsk, u32 cid, u32 port)
 {
 	return false;
 }
diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index 7eccd6708d66..00f6bbdb035a 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -646,13 +646,17 @@ static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
 	return VMCI_SUCCESS;
 }
 
-static bool vmci_transport_stream_allow(u32 cid, u32 port)
+static bool vmci_transport_stream_allow(struct vsock_sock *vsk, u32 cid,
+					u32 port)
 {
 	static const u32 non_socket_contexts[] = {
 		VMADDR_CID_LOCAL,
 	};
 	int i;
 
+	if (!vsock_net_mode_global(vsk))
+		return false;
+
 	BUILD_BUG_ON(sizeof(cid) != sizeof(*non_socket_contexts));
 
 	for (i = 0; i < ARRAY_SIZE(non_socket_contexts); i++) {
@@ -682,12 +686,10 @@ static int vmci_transport_recv_stream_cb(void *data, struct vmci_datagram *dg)
 	err = VMCI_SUCCESS;
 	bh_process_pkt = false;
 
-	/* Ignore incoming packets from contexts without sockets, or resources
-	 * that aren't vsock implementations.
+	/* Ignore incoming packets from resources that aren't vsock
+	 * implementations.
 	 */
-
-	if (!vmci_transport_stream_allow(dg->src.context, -1)
-	    || vmci_transport_peer_rid(dg->src.context) != dg->src.resource)
+	if (vmci_transport_peer_rid(dg->src.context) != dg->src.resource)
 		return VMCI_ERROR_NO_ACCESS;
 
 	if (VMCI_DG_SIZE(dg) < sizeof(*pkt))
@@ -749,6 +751,12 @@ static int vmci_transport_recv_stream_cb(void *data, struct vmci_datagram *dg)
 		goto out;
 	}
 
+	/* Ignore incoming packets from contexts without sockets. */
+	if (!vmci_transport_stream_allow(vsk, dg->src.context, -1)) {
+		err = VMCI_ERROR_NO_ACCESS;
+		goto out;
+	}
+
 	/* We do most everything in a work queue, but let's fast path the
 	 * notification of reads and writes to help data transfer performance.
 	 * We can only do this if there is no process context code executing
@@ -1784,8 +1792,12 @@ static int vmci_transport_dgram_dequeue(struct vsock_sock *vsk,
 	return err;
 }
 
-static bool vmci_transport_dgram_allow(u32 cid, u32 port)
+static bool vmci_transport_dgram_allow(struct vsock_sock *vsk, u32 cid,
+				       u32 port)
 {
+	if (!vsock_net_mode_global(vsk))
+		return false;
+
 	if (cid == VMADDR_CID_HYPERVISOR) {
 		/* Registrations of PBRPC Servers do not modify VMX/Hypervisor
 		 * state and are allowed.
diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
index bc2ff918b315..deff68c64a09 100644
--- a/net/vmw_vsock/vsock_loopback.c
+++ b/net/vmw_vsock/vsock_loopback.c
@@ -46,7 +46,8 @@ static int vsock_loopback_cancel_pkt(struct vsock_sock *vsk)
 	return 0;
 }
 
-static bool vsock_loopback_seqpacket_allow(u32 remote_cid);
+static bool vsock_loopback_seqpacket_allow(struct vsock_sock *vsk,
+					   u32 remote_cid);
 static bool vsock_loopback_msgzerocopy_allow(void)
 {
 	return true;
@@ -106,9 +107,10 @@ static struct virtio_transport loopback_transport = {
 	.send_pkt = vsock_loopback_send_pkt,
 };
 
-static bool vsock_loopback_seqpacket_allow(u32 remote_cid)
+static bool
+vsock_loopback_seqpacket_allow(struct vsock_sock *vsk, u32 remote_cid)
 {
-	return true;
+	return vsock_net_mode_global(vsk);
 }
 
 static void vsock_loopback_work(struct work_struct *work)

-- 
2.47.3

[PATCH net-next v16 02/12] virtio: set skb owner of virtio_transport_reset_no_sock() reply

[Bobby Eshleman]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Associate reply packets with the sending socket. When vsock must reply
with an RST packet and there exists a sending socket (e.g., for
loopback), setting the skb owner to the socket correctly handles
reference counting between the skb and sk (i.e., the sk stays alive
until the skb is freed).

This allows the net namespace to be used for socket lookups for the
duration of the reply skb's lifetime, preventing race conditions between
the namespace lifecycle and vsock socket search using the namespace
pointer.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
Changes in v11:
- move before adding to netns support (Stefano)

Changes in v10:
- break this out into its own patch for easy revert (Stefano)
---
 net/vmw_vsock/virtio_transport_common.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index fdb8f5b3fa60..718be9f33274 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1165,6 +1165,12 @@ static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
 		.op = VIRTIO_VSOCK_OP_RST,
 		.type = le16_to_cpu(hdr->type),
 		.reply = true,
+
+		/* Set sk owner to socket we are replying to (may be NULL for
+		 * non-loopback). This keeps a reference to the sock and
+		 * sock_net(sk) until the reply skb is freed.
+		 */
+		.vsk = vsock_sk(skb->sk),
 	};
 	struct sk_buff *reply;
 

-- 
2.47.3

[PATCH net-next v16 03/12] vsock: add netns support to virtio transports

[Bobby Eshleman]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Add netns support to loopback and vhost. Keep netns disabled for
virtio-vsock, but add necessary changes to comply with common API
updates.

This is the patch in the series when vhost-vsock namespaces actually
come online.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
Changes in v15:
- add vsock_net_mode_global() (Stefano)

Changes in v14:
- fixed merge conflicts in drivers/vhost/vsock.c

Changes in v13:
- do not store or pass the mode around now that net->vsock.mode is
  immutable
- move virtio_transport_stream_allow() into virtio_transport.c
  because virtio is the only caller now

Changes in v12:
- change seqpacket_allow() and stream_allow() to return true for
  loopback and vhost (Stefano)

Changes in v11:
- reorder with the skb ownership patch for loopback (Stefano)
- toggle vhost_transport_supports_local_mode() to true

Changes in v10:
- Splitting patches complicates the series with meaningless placeholder
  values that eventually get replaced anyway, so to avoid that this
  patch combines into one. Links to previous patches here:
  - Link: https://lore.kernel.org/all/20251111-vsock-vmtest-v9-3-852787a37bed@meta.com/
  - Link: https://lore.kernel.org/all/20251111-vsock-vmtest-v9-6-852787a37bed@meta.com/
  - Link: https://lore.kernel.org/all/20251111-vsock-vmtest-v9-7-852787a37bed@meta.com/
- remove placeholder values (Stefano)
- update comment describe net/net_mode for
  virtio_transport_reset_no_sock()
---
 drivers/vhost/vsock.c                   | 38 ++++++++++++++++-------
 include/linux/virtio_vsock.h            |  5 +--
 net/vmw_vsock/virtio_transport.c        | 13 ++++++--
 net/vmw_vsock/virtio_transport_common.c | 54 +++++++++++++++++++--------------
 net/vmw_vsock/vsock_loopback.c          | 14 +++++++--
 5 files changed, 84 insertions(+), 40 deletions(-)

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 647ded6f6ea5..488d7fa6e4ec 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -48,6 +48,8 @@ static DEFINE_READ_MOSTLY_HASHTABLE(vhost_vsock_hash, 8);
 struct vhost_vsock {
 	struct vhost_dev dev;
 	struct vhost_virtqueue vqs[2];
+	struct net *net;
+	netns_tracker ns_tracker;
 
 	/* Link to global vhost_vsock_hash, writes use vhost_vsock_mutex */
 	struct hlist_node hash;
@@ -69,7 +71,7 @@ static u32 vhost_transport_get_local_cid(void)
 /* Callers must be in an RCU read section or hold the vhost_vsock_mutex.
  * The return value can only be dereferenced while within the section.
  */
-static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
+static struct vhost_vsock *vhost_vsock_get(u32 guest_cid, struct net *net)
 {
 	struct vhost_vsock *vsock;
 
@@ -81,9 +83,9 @@ static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
 		if (other_cid == 0)
 			continue;
 
-		if (other_cid == guest_cid)
+		if (other_cid == guest_cid &&
+		    vsock_net_check_mode(net, vsock->net))
 			return vsock;
-
 	}
 
 	return NULL;
@@ -272,7 +274,7 @@ static void vhost_transport_send_pkt_work(struct vhost_work *work)
 }
 
 static int
-vhost_transport_send_pkt(struct sk_buff *skb)
+vhost_transport_send_pkt(struct sk_buff *skb, struct net *net)
 {
 	struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
 	struct vhost_vsock *vsock;
@@ -281,7 +283,7 @@ vhost_transport_send_pkt(struct sk_buff *skb)
 	rcu_read_lock();
 
 	/* Find the vhost_vsock according to guest context id  */
-	vsock = vhost_vsock_get(le64_to_cpu(hdr->dst_cid));
+	vsock = vhost_vsock_get(le64_to_cpu(hdr->dst_cid), net);
 	if (!vsock) {
 		rcu_read_unlock();
 		kfree_skb(skb);
@@ -308,7 +310,8 @@ vhost_transport_cancel_pkt(struct vsock_sock *vsk)
 	rcu_read_lock();
 
 	/* Find the vhost_vsock according to guest context id  */
-	vsock = vhost_vsock_get(vsk->remote_addr.svm_cid);
+	vsock = vhost_vsock_get(vsk->remote_addr.svm_cid,
+				sock_net(sk_vsock(vsk)));
 	if (!vsock)
 		goto out;
 
@@ -410,6 +413,12 @@ static bool vhost_transport_msgzerocopy_allow(void)
 static bool vhost_transport_seqpacket_allow(struct vsock_sock *vsk,
 					    u32 remote_cid);
 
+static bool
+vhost_transport_stream_allow(struct vsock_sock *vsk, u32 cid, u32 port)
+{
+	return true;
+}
+
 static struct virtio_transport vhost_transport = {
 	.transport = {
 		.module                   = THIS_MODULE,
@@ -434,7 +443,7 @@ static struct virtio_transport vhost_transport = {
 		.stream_has_space         = virtio_transport_stream_has_space,
 		.stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
 		.stream_is_active         = virtio_transport_stream_is_active,
-		.stream_allow             = virtio_transport_stream_allow,
+		.stream_allow             = vhost_transport_stream_allow,
 
 		.seqpacket_dequeue        = virtio_transport_seqpacket_dequeue,
 		.seqpacket_enqueue        = virtio_transport_seqpacket_enqueue,
@@ -467,11 +476,12 @@ static struct virtio_transport vhost_transport = {
 static bool vhost_transport_seqpacket_allow(struct vsock_sock *vsk,
 					    u32 remote_cid)
 {
+	struct net *net = sock_net(sk_vsock(vsk));
 	struct vhost_vsock *vsock;
 	bool seqpacket_allow = false;
 
 	rcu_read_lock();
-	vsock = vhost_vsock_get(remote_cid);
+	vsock = vhost_vsock_get(remote_cid, net);
 
 	if (vsock)
 		seqpacket_allow = vsock->seqpacket_allow;
@@ -542,7 +552,8 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
 		if (le64_to_cpu(hdr->src_cid) == vsock->guest_cid &&
 		    le64_to_cpu(hdr->dst_cid) ==
 		    vhost_transport_get_local_cid())
-			virtio_transport_recv_pkt(&vhost_transport, skb);
+			virtio_transport_recv_pkt(&vhost_transport, skb,
+						  vsock->net);
 		else
 			kfree_skb(skb);
 
@@ -659,6 +670,7 @@ static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
 {
 	struct vhost_virtqueue **vqs;
 	struct vhost_vsock *vsock;
+	struct net *net;
 	int ret;
 
 	/* This struct is large and allocation could fail, fall back to vmalloc
@@ -674,6 +686,9 @@ static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
 		goto out;
 	}
 
+	net = current->nsproxy->net_ns;
+	vsock->net = get_net_track(net, &vsock->ns_tracker, GFP_KERNEL);
+
 	vsock->guest_cid = 0; /* no CID assigned yet */
 	vsock->seqpacket_allow = false;
 
@@ -715,7 +730,7 @@ static void vhost_vsock_reset_orphans(struct sock *sk)
 	rcu_read_lock();
 
 	/* If the peer is still valid, no need to reset connection */
-	if (vhost_vsock_get(vsk->remote_addr.svm_cid)) {
+	if (vhost_vsock_get(vsk->remote_addr.svm_cid, sock_net(sk))) {
 		rcu_read_unlock();
 		return;
 	}
@@ -764,6 +779,7 @@ static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
 	virtio_vsock_skb_queue_purge(&vsock->send_pkt_queue);
 
 	vhost_dev_cleanup(&vsock->dev);
+	put_net_track(vsock->net, &vsock->ns_tracker);
 	kfree(vsock->dev.vqs);
 	vhost_vsock_free(vsock);
 	return 0;
@@ -790,7 +806,7 @@ static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
 
 	/* Refuse if CID is already in use */
 	mutex_lock(&vhost_vsock_mutex);
-	other = vhost_vsock_get(guest_cid);
+	other = vhost_vsock_get(guest_cid, vsock->net);
 	if (other && other != vsock) {
 		mutex_unlock(&vhost_vsock_mutex);
 		return -EADDRINUSE;
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index 1845e8d4f78d..f91704731057 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h
@@ -173,6 +173,7 @@ struct virtio_vsock_pkt_info {
 	u32 remote_cid, remote_port;
 	struct vsock_sock *vsk;
 	struct msghdr *msg;
+	struct net *net;
 	u32 pkt_len;
 	u16 type;
 	u16 op;
@@ -185,7 +186,7 @@ struct virtio_transport {
 	struct vsock_transport transport;
 
 	/* Takes ownership of the packet */
-	int (*send_pkt)(struct sk_buff *skb);
+	int (*send_pkt)(struct sk_buff *skb, struct net *net);
 
 	/* Used in MSG_ZEROCOPY mode. Checks, that provided data
 	 * (number of buffers) could be transmitted with zerocopy
@@ -280,7 +281,7 @@ virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
 void virtio_transport_destruct(struct vsock_sock *vsk);
 
 void virtio_transport_recv_pkt(struct virtio_transport *t,
-			       struct sk_buff *skb);
+			       struct sk_buff *skb, struct net *net);
 void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct sk_buff *skb);
 u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 wanted);
 void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit);
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index f0a9e51118f3..3f7ea2db9bd7 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -231,7 +231,7 @@ static int virtio_transport_send_skb_fast_path(struct virtio_vsock *vsock, struc
 }
 
 static int
-virtio_transport_send_pkt(struct sk_buff *skb)
+virtio_transport_send_pkt(struct sk_buff *skb, struct net *net)
 {
 	struct virtio_vsock_hdr *hdr;
 	struct virtio_vsock *vsock;
@@ -536,6 +536,11 @@ static bool virtio_transport_msgzerocopy_allow(void)
 	return true;
 }
 
+bool virtio_transport_stream_allow(struct vsock_sock *vsk, u32 cid, u32 port)
+{
+	return vsock_net_mode_global(vsk);
+}
+
 static bool virtio_transport_seqpacket_allow(struct vsock_sock *vsk,
 					     u32 remote_cid);
 
@@ -665,7 +670,11 @@ static void virtio_transport_rx_work(struct work_struct *work)
 				virtio_vsock_skb_put(skb, payload_len);
 
 			virtio_transport_deliver_tap_pkt(skb);
-			virtio_transport_recv_pkt(&virtio_transport, skb);
+
+			/* Force virtio-transport into global mode since it
+			 * does not yet support local-mode namespacing.
+			 */
+			virtio_transport_recv_pkt(&virtio_transport, skb, NULL);
 		}
 	} while (!virtqueue_enable_cb(vq));
 
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 718be9f33274..c126aa235091 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -413,7 +413,7 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
 
 		virtio_transport_inc_tx_pkt(vvs, skb);
 
-		ret = t_ops->send_pkt(skb);
+		ret = t_ops->send_pkt(skb, info->net);
 		if (ret < 0)
 			break;
 
@@ -527,6 +527,7 @@ static int virtio_transport_send_credit_update(struct vsock_sock *vsk)
 	struct virtio_vsock_pkt_info info = {
 		.op = VIRTIO_VSOCK_OP_CREDIT_UPDATE,
 		.vsk = vsk,
+		.net = sock_net(sk_vsock(vsk)),
 	};
 
 	return virtio_transport_send_pkt_info(vsk, &info);
@@ -1043,12 +1044,6 @@ bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
 }
 EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
 
-bool virtio_transport_stream_allow(struct vsock_sock *vsk, u32 cid, u32 port)
-{
-	return vsock_net_mode(sock_net(sk_vsock(vsk))) == VSOCK_NET_MODE_GLOBAL;
-}
-EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
-
 int virtio_transport_dgram_bind(struct vsock_sock *vsk,
 				struct sockaddr_vm *addr)
 {
@@ -1067,6 +1062,7 @@ int virtio_transport_connect(struct vsock_sock *vsk)
 	struct virtio_vsock_pkt_info info = {
 		.op = VIRTIO_VSOCK_OP_REQUEST,
 		.vsk = vsk,
+		.net = sock_net(sk_vsock(vsk)),
 	};
 
 	return virtio_transport_send_pkt_info(vsk, &info);
@@ -1082,6 +1078,7 @@ int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
 			 (mode & SEND_SHUTDOWN ?
 			  VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
 		.vsk = vsk,
+		.net = sock_net(sk_vsock(vsk)),
 	};
 
 	return virtio_transport_send_pkt_info(vsk, &info);
@@ -1108,6 +1105,7 @@ virtio_transport_stream_enqueue(struct vsock_sock *vsk,
 		.msg = msg,
 		.pkt_len = len,
 		.vsk = vsk,
+		.net = sock_net(sk_vsock(vsk)),
 	};
 
 	return virtio_transport_send_pkt_info(vsk, &info);
@@ -1145,6 +1143,7 @@ static int virtio_transport_reset(struct vsock_sock *vsk,
 		.op = VIRTIO_VSOCK_OP_RST,
 		.reply = !!skb,
 		.vsk = vsk,
+		.net = sock_net(sk_vsock(vsk)),
 	};
 
 	/* Send RST only if the original pkt is not a RST pkt */
@@ -1156,9 +1155,13 @@ static int virtio_transport_reset(struct vsock_sock *vsk,
 
 /* Normally packets are associated with a socket.  There may be no socket if an
  * attempt was made to connect to a socket that does not exist.
+ *
+ * net refers to the namespace of whoever sent the invalid message. For
+ * loopback, this is the namespace of the socket. For vhost, this is the
+ * namespace of the VM (i.e., vhost_vsock).
  */
 static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
-					  struct sk_buff *skb)
+					  struct sk_buff *skb, struct net *net)
 {
 	struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
 	struct virtio_vsock_pkt_info info = {
@@ -1171,6 +1174,12 @@ static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
 		 * sock_net(sk) until the reply skb is freed.
 		 */
 		.vsk = vsock_sk(skb->sk),
+
+		/* net is not defined here because we pass it directly to
+		 * t->send_pkt(), instead of relying on
+		 * virtio_transport_send_pkt_info() to pass it. It is not needed
+		 * by virtio_transport_alloc_skb().
+		 */
 	};
 	struct sk_buff *reply;
 
@@ -1189,7 +1198,7 @@ static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
 	if (!reply)
 		return -ENOMEM;
 
-	return t->send_pkt(reply);
+	return t->send_pkt(reply, net);
 }
 
 /* This function should be called with sk_lock held and SOCK_DONE set */
@@ -1471,6 +1480,7 @@ virtio_transport_send_response(struct vsock_sock *vsk,
 		.remote_port = le32_to_cpu(hdr->src_port),
 		.reply = true,
 		.vsk = vsk,
+		.net = sock_net(sk_vsock(vsk)),
 	};
 
 	return virtio_transport_send_pkt_info(vsk, &info);
@@ -1513,12 +1523,12 @@ virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
 	int ret;
 
 	if (le16_to_cpu(hdr->op) != VIRTIO_VSOCK_OP_REQUEST) {
-		virtio_transport_reset_no_sock(t, skb);
+		virtio_transport_reset_no_sock(t, skb, sock_net(sk));
 		return -EINVAL;
 	}
 
 	if (sk_acceptq_is_full(sk)) {
-		virtio_transport_reset_no_sock(t, skb);
+		virtio_transport_reset_no_sock(t, skb, sock_net(sk));
 		return -ENOMEM;
 	}
 
@@ -1526,13 +1536,13 @@ virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
 	 * Subsequent enqueues would lead to a memory leak.
 	 */
 	if (sk->sk_shutdown == SHUTDOWN_MASK) {
-		virtio_transport_reset_no_sock(t, skb);
+		virtio_transport_reset_no_sock(t, skb, sock_net(sk));
 		return -ESHUTDOWN;
 	}
 
 	child = vsock_create_connected(sk);
 	if (!child) {
-		virtio_transport_reset_no_sock(t, skb);
+		virtio_transport_reset_no_sock(t, skb, sock_net(sk));
 		return -ENOMEM;
 	}
 
@@ -1554,7 +1564,7 @@ virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
 	 */
 	if (ret || vchild->transport != &t->transport) {
 		release_sock(child);
-		virtio_transport_reset_no_sock(t, skb);
+		virtio_transport_reset_no_sock(t, skb, sock_net(sk));
 		sock_put(child);
 		return ret;
 	}
@@ -1582,7 +1592,7 @@ static bool virtio_transport_valid_type(u16 type)
  * lock.
  */
 void virtio_transport_recv_pkt(struct virtio_transport *t,
-			       struct sk_buff *skb)
+			       struct sk_buff *skb, struct net *net)
 {
 	struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
 	struct sockaddr_vm src, dst;
@@ -1605,24 +1615,24 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
 					le32_to_cpu(hdr->fwd_cnt));
 
 	if (!virtio_transport_valid_type(le16_to_cpu(hdr->type))) {
-		(void)virtio_transport_reset_no_sock(t, skb);
+		(void)virtio_transport_reset_no_sock(t, skb, net);
 		goto free_pkt;
 	}
 
 	/* The socket must be in connected or bound table
 	 * otherwise send reset back
 	 */
-	sk = vsock_find_connected_socket(&src, &dst);
+	sk = vsock_find_connected_socket_net(&src, &dst, net);
 	if (!sk) {
-		sk = vsock_find_bound_socket(&dst);
+		sk = vsock_find_bound_socket_net(&dst, net);
 		if (!sk) {
-			(void)virtio_transport_reset_no_sock(t, skb);
+			(void)virtio_transport_reset_no_sock(t, skb, net);
 			goto free_pkt;
 		}
 	}
 
 	if (virtio_transport_get_type(sk) != le16_to_cpu(hdr->type)) {
-		(void)virtio_transport_reset_no_sock(t, skb);
+		(void)virtio_transport_reset_no_sock(t, skb, net);
 		sock_put(sk);
 		goto free_pkt;
 	}
@@ -1641,7 +1651,7 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
 	 */
 	if (sock_flag(sk, SOCK_DONE) ||
 	    (sk->sk_state != TCP_LISTEN && vsk->transport != &t->transport)) {
-		(void)virtio_transport_reset_no_sock(t, skb);
+		(void)virtio_transport_reset_no_sock(t, skb, net);
 		release_sock(sk);
 		sock_put(sk);
 		goto free_pkt;
@@ -1673,7 +1683,7 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
 		kfree_skb(skb);
 		break;
 	default:
-		(void)virtio_transport_reset_no_sock(t, skb);
+		(void)virtio_transport_reset_no_sock(t, skb, net);
 		kfree_skb(skb);
 		break;
 	}
diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
index deff68c64a09..8068d1b6e851 100644
--- a/net/vmw_vsock/vsock_loopback.c
+++ b/net/vmw_vsock/vsock_loopback.c
@@ -26,7 +26,7 @@ static u32 vsock_loopback_get_local_cid(void)
 	return VMADDR_CID_LOCAL;
 }
 
-static int vsock_loopback_send_pkt(struct sk_buff *skb)
+static int vsock_loopback_send_pkt(struct sk_buff *skb, struct net *net)
 {
 	struct vsock_loopback *vsock = &the_vsock_loopback;
 	int len = skb->len;
@@ -48,6 +48,13 @@ static int vsock_loopback_cancel_pkt(struct vsock_sock *vsk)
 
 static bool vsock_loopback_seqpacket_allow(struct vsock_sock *vsk,
 					   u32 remote_cid);
+
+static bool vsock_loopback_stream_allow(struct vsock_sock *vsk, u32 cid,
+					u32 port)
+{
+	return true;
+}
+
 static bool vsock_loopback_msgzerocopy_allow(void)
 {
 	return true;
@@ -77,7 +84,7 @@ static struct virtio_transport loopback_transport = {
 		.stream_has_space         = virtio_transport_stream_has_space,
 		.stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
 		.stream_is_active         = virtio_transport_stream_is_active,
-		.stream_allow             = virtio_transport_stream_allow,
+		.stream_allow             = vsock_loopback_stream_allow,
 
 		.seqpacket_dequeue        = virtio_transport_seqpacket_dequeue,
 		.seqpacket_enqueue        = virtio_transport_seqpacket_enqueue,
@@ -132,7 +139,8 @@ static void vsock_loopback_work(struct work_struct *work)
 		 */
 		virtio_transport_consume_skb_sent(skb, false);
 		virtio_transport_deliver_tap_pkt(skb);
-		virtio_transport_recv_pkt(&loopback_transport, skb);
+		virtio_transport_recv_pkt(&loopback_transport, skb,
+					  sock_net(skb->sk));
 	}
 }
 

-- 
2.47.3

[PATCH net-next v16 04/12] selftests/vsock: increase timeout to 1200

[Bobby Eshleman]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Increase the timeout from 300s to 1200s. On a modern bare metal server
my last run showed the new set of tests taking ~400s. Multiply by an
(arbitrary) factor of three to account for slower/nested runners.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
 tools/testing/selftests/vsock/settings | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/vsock/settings b/tools/testing/selftests/vsock/settings
index 694d70710ff0..79b65bdf05db 100644
--- a/tools/testing/selftests/vsock/settings
+++ b/tools/testing/selftests/vsock/settings
@@ -1 +1 @@
-timeout=300
+timeout=1200

-- 
2.47.3

[PATCH net-next v16 05/12] selftests/vsock: add namespace helpers to vmtest.sh

[Bobby Eshleman]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Add functions for initializing namespaces with the different vsock NS
modes. Callers can use add_namespaces() and del_namespaces() to create
namespaces global0, global1, local0, and local1.

The add_namespaces() function initializes global0, local0, etc... with
their respective vsock NS mode by toggling child_ns_mode before creating
the namespace.

Remove namespaces upon exiting the program in cleanup(). This is
unlikely to be needed for a healthy run, but it is useful for tests that
are manually killed mid-test.

This patch is in preparation for later namespace tests.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
Changes in v13:
- intialize namespaces to use the child_ns_mode mechanism
- remove setting modes from init_namespaces() function (this function
  only sets up the lo device now)
- remove ns_set_mode(ns) because ns_mode is no longer mutable
---
 tools/testing/selftests/vsock/vmtest.sh | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index c7b270dd77a9..c2bdc293b94c 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -49,6 +49,7 @@ readonly TEST_DESCS=(
 )
 
 readonly USE_SHARED_VM=(vm_server_host_client vm_client_host_server vm_loopback)
+readonly NS_MODES=("local" "global")
 
 VERBOSE=0
 
@@ -103,6 +104,36 @@ check_result() {
 	fi
 }
 
+add_namespaces() {
+	local orig_mode
+	orig_mode=$(cat /proc/sys/net/vsock/child_ns_mode)
+
+	for mode in "${NS_MODES[@]}"; do
+		echo "${mode}" > /proc/sys/net/vsock/child_ns_mode
+		ip netns add "${mode}0" 2>/dev/null
+		ip netns add "${mode}1" 2>/dev/null
+	done
+
+	echo "${orig_mode}" > /proc/sys/net/vsock/child_ns_mode
+}
+
+init_namespaces() {
+	for mode in "${NS_MODES[@]}"; do
+		# we need lo for qemu port forwarding
+		ip netns exec "${mode}0" ip link set dev lo up
+		ip netns exec "${mode}1" ip link set dev lo up
+	done
+}
+
+del_namespaces() {
+	for mode in "${NS_MODES[@]}"; do
+		ip netns del "${mode}0" &>/dev/null
+		ip netns del "${mode}1" &>/dev/null
+		log_host "removed ns ${mode}0"
+		log_host "removed ns ${mode}1"
+	done
+}
+
 vm_ssh() {
 	ssh -q -o UserKnownHostsFile=/dev/null -p ${SSH_HOST_PORT} localhost "$@"
 	return $?
@@ -110,6 +141,7 @@ vm_ssh() {
 
 cleanup() {
 	terminate_pidfiles "${!PIDFILES[@]}"
+	del_namespaces
 }
 
 check_args() {

-- 
2.47.3

[PATCH net-next v16 06/12] selftests/vsock: prepare vm management helpers for namespaces

[Bobby Eshleman]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Add namespace support to vm management, ssh helpers, and vsock_test
wrapper functions. This enables running VMs and test helpers in specific
namespaces, which is required for upcoming namespace isolation tests.

The functions still work correctly within the init ns, though the caller
must now pass "init_ns" explicitly.

No functional changes for existing tests. All have been updated to pass
"init_ns" explicitly.

Affected functions (such as vm_start() and vm_ssh()) now wrap their
commands with 'ip netns exec' when executing commands in non-init
namespaces.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
Changes in v16:
- add "init_ns" to vm_ssh calls in run_shared_vm_tests
---
 tools/testing/selftests/vsock/vmtest.sh | 101 ++++++++++++++++++++++----------
 1 file changed, 69 insertions(+), 32 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index c2bdc293b94c..c4d73dd0a4cf 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -135,7 +135,18 @@ del_namespaces() {
 }
 
 vm_ssh() {
-	ssh -q -o UserKnownHostsFile=/dev/null -p ${SSH_HOST_PORT} localhost "$@"
+	local ns_exec
+
+	if [[ "${1}" == init_ns ]]; then
+		ns_exec=""
+	else
+		ns_exec="ip netns exec ${1}"
+	fi
+
+	shift
+
+	${ns_exec} ssh -q -o UserKnownHostsFile=/dev/null -p "${SSH_HOST_PORT}" localhost "$@"
+
 	return $?
 }
 
@@ -258,10 +269,12 @@ terminate_pidfiles() {
 
 vm_start() {
 	local pidfile=$1
+	local ns=$2
 	local logfile=/dev/null
 	local verbose_opt=""
 	local kernel_opt=""
 	local qemu_opts=""
+	local ns_exec=""
 	local qemu
 
 	qemu=$(command -v "${QEMU}")
@@ -282,7 +295,11 @@ vm_start() {
 		kernel_opt="${KERNEL_CHECKOUT}"
 	fi
 
-	vng \
+	if [[ "${ns}" != "init_ns" ]]; then
+		ns_exec="ip netns exec ${ns}"
+	fi
+
+	${ns_exec} vng \
 		--run \
 		${kernel_opt} \
 		${verbose_opt} \
@@ -297,6 +314,7 @@ vm_start() {
 }
 
 vm_wait_for_ssh() {
+	local ns=$1
 	local i
 
 	i=0
@@ -304,7 +322,8 @@ vm_wait_for_ssh() {
 		if [[ ${i} -gt ${WAIT_PERIOD_MAX} ]]; then
 			die "Timed out waiting for guest ssh"
 		fi
-		if vm_ssh -- true; then
+
+		if vm_ssh "${ns}" -- true; then
 			break
 		fi
 		i=$(( i + 1 ))
@@ -338,30 +357,41 @@ wait_for_listener()
 }
 
 vm_wait_for_listener() {
-	local port=$1
+	local ns=$1
+	local port=$2
 
-	vm_ssh <<EOF
+	vm_ssh "${ns}" <<EOF
 $(declare -f wait_for_listener)
 wait_for_listener ${port} ${WAIT_PERIOD} ${WAIT_PERIOD_MAX}
 EOF
 }
 
 host_wait_for_listener() {
-	local port=$1
+	local ns=$1
+	local port=$2
 
-	wait_for_listener "${port}" "${WAIT_PERIOD}" "${WAIT_PERIOD_MAX}"
+	if [[ "${ns}" == "init_ns" ]]; then
+		wait_for_listener "${port}" "${WAIT_PERIOD}" "${WAIT_PERIOD_MAX}"
+	else
+		ip netns exec "${ns}" bash <<-EOF
+			$(declare -f wait_for_listener)
+			wait_for_listener ${port} ${WAIT_PERIOD} ${WAIT_PERIOD_MAX}
+		EOF
+	fi
 }
 
+
 vm_vsock_test() {
-	local host=$1
-	local cid=$2
-	local port=$3
+	local ns=$1
+	local host=$2
+	local cid=$3
+	local port=$4
 	local rc
 
 	# log output and use pipefail to respect vsock_test errors
 	set -o pipefail
 	if [[ "${host}" != server ]]; then
-		vm_ssh -- "${VSOCK_TEST}" \
+		vm_ssh "${ns}" -- "${VSOCK_TEST}" \
 			--mode=client \
 			--control-host="${host}" \
 			--peer-cid="${cid}" \
@@ -369,7 +399,7 @@ vm_vsock_test() {
 			2>&1 | log_guest
 		rc=$?
 	else
-		vm_ssh -- "${VSOCK_TEST}" \
+		vm_ssh "${ns}" -- "${VSOCK_TEST}" \
 			--mode=server \
 			--peer-cid="${cid}" \
 			--control-port="${port}" \
@@ -381,7 +411,7 @@ vm_vsock_test() {
 			return $rc
 		fi
 
-		vm_wait_for_listener "${port}"
+		vm_wait_for_listener "${ns}" "${port}"
 		rc=$?
 	fi
 	set +o pipefail
@@ -390,22 +420,28 @@ vm_vsock_test() {
 }
 
 host_vsock_test() {
-	local host=$1
-	local cid=$2
-	local port=$3
+	local ns=$1
+	local host=$2
+	local cid=$3
+	local port=$4
 	local rc
 
+	local cmd="${VSOCK_TEST}"
+	if [[ "${ns}" != "init_ns" ]]; then
+		cmd="ip netns exec ${ns} ${cmd}"
+	fi
+
 	# log output and use pipefail to respect vsock_test errors
 	set -o pipefail
 	if [[ "${host}" != server ]]; then
-		${VSOCK_TEST} \
+		${cmd} \
 			--mode=client \
 			--peer-cid="${cid}" \
 			--control-host="${host}" \
 			--control-port="${port}" 2>&1 | log_host
 		rc=$?
 	else
-		${VSOCK_TEST} \
+		${cmd} \
 			--mode=server \
 			--peer-cid="${cid}" \
 			--control-port="${port}" 2>&1 | log_host &
@@ -416,7 +452,7 @@ host_vsock_test() {
 			return $rc
 		fi
 
-		host_wait_for_listener "${port}"
+		host_wait_for_listener "${ns}" "${port}"
 		rc=$?
 	fi
 	set +o pipefail
@@ -460,11 +496,11 @@ log_guest() {
 }
 
 test_vm_server_host_client() {
-	if ! vm_vsock_test "server" 2 "${TEST_GUEST_PORT}"; then
+	if ! vm_vsock_test "init_ns" "server" 2 "${TEST_GUEST_PORT}"; then
 		return "${KSFT_FAIL}"
 	fi
 
-	if ! host_vsock_test "127.0.0.1" "${VSOCK_CID}" "${TEST_HOST_PORT}"; then
+	if ! host_vsock_test "init_ns" "127.0.0.1" "${VSOCK_CID}" "${TEST_HOST_PORT}"; then
 		return "${KSFT_FAIL}"
 	fi
 
@@ -472,11 +508,11 @@ test_vm_server_host_client() {
 }
 
 test_vm_client_host_server() {
-	if ! host_vsock_test "server" "${VSOCK_CID}" "${TEST_HOST_PORT_LISTENER}"; then
+	if ! host_vsock_test "init_ns" "server" "${VSOCK_CID}" "${TEST_HOST_PORT_LISTENER}"; then
 		return "${KSFT_FAIL}"
 	fi
 
-	if ! vm_vsock_test "10.0.2.2" 2 "${TEST_HOST_PORT_LISTENER}"; then
+	if ! vm_vsock_test "init_ns" "10.0.2.2" 2 "${TEST_HOST_PORT_LISTENER}"; then
 		return "${KSFT_FAIL}"
 	fi
 
@@ -486,13 +522,14 @@ test_vm_client_host_server() {
 test_vm_loopback() {
 	local port=60000 # non-forwarded local port
 
-	vm_ssh -- modprobe vsock_loopback &> /dev/null || :
+	vm_ssh "init_ns" -- modprobe vsock_loopback &> /dev/null || :
 
-	if ! vm_vsock_test "server" 1 "${port}"; then
+	if ! vm_vsock_test "init_ns" "server" 1 "${port}"; then
 		return "${KSFT_FAIL}"
 	fi
 
-	if ! vm_vsock_test "127.0.0.1" 1 "${port}"; then
+
+	if ! vm_vsock_test "init_ns" "127.0.0.1" 1 "${port}"; then
 		return "${KSFT_FAIL}"
 	fi
 
@@ -550,8 +587,8 @@ run_shared_vm_test() {
 
 	host_oops_cnt_before=$(dmesg | grep -c -i 'Oops')
 	host_warn_cnt_before=$(dmesg --level=warn | grep -c -i 'vsock')
-	vm_oops_cnt_before=$(vm_ssh -- dmesg | grep -c -i 'Oops')
-	vm_warn_cnt_before=$(vm_ssh -- dmesg --level=warn | grep -c -i 'vsock')
+	vm_oops_cnt_before=$(vm_ssh "init_ns" -- dmesg | grep -c -i 'Oops')
+	vm_warn_cnt_before=$(vm_ssh "init_ns" -- dmesg --level=warn | grep -c -i 'vsock')
 
 	name=$(echo "${1}" | awk '{ print $1 }')
 	eval test_"${name}"
@@ -569,13 +606,13 @@ run_shared_vm_test() {
 		rc=$KSFT_FAIL
 	fi
 
-	vm_oops_cnt_after=$(vm_ssh -- dmesg | grep -i 'Oops' | wc -l)
+	vm_oops_cnt_after=$(vm_ssh "init_ns" -- dmesg | grep -i 'Oops' | wc -l)
 	if [[ ${vm_oops_cnt_after} -gt ${vm_oops_cnt_before} ]]; then
 		echo "FAIL: kernel oops detected on vm" | log_host
 		rc=$KSFT_FAIL
 	fi
 
-	vm_warn_cnt_after=$(vm_ssh -- dmesg --level=warn | grep -c -i 'vsock')
+	vm_warn_cnt_after=$(vm_ssh "init_ns" -- dmesg --level=warn | grep -c -i 'vsock')
 	if [[ ${vm_warn_cnt_after} -gt ${vm_warn_cnt_before} ]]; then
 		echo "FAIL: kernel warning detected on vm" | log_host
 		rc=$KSFT_FAIL
@@ -621,8 +658,8 @@ cnt_total=0
 if shared_vm_tests_requested "${ARGS[@]}"; then
 	log_host "Booting up VM"
 	pidfile="$(create_pidfile)"
-	vm_start "${pidfile}"
-	vm_wait_for_ssh
+	vm_start "${pidfile}" "init_ns"
+	vm_wait_for_ssh "init_ns"
 	log_host "VM booted up"
 
 	run_shared_vm_tests "${ARGS[@]}"

-- 
2.47.3

[PATCH net-next v16 07/12] selftests/vsock: add vm_dmesg_{warn,oops}_count() helpers

[Bobby Eshleman]

From: Bobby Eshleman <bobbyeshleman@meta.com>

These functions are reused by the VM tests to collect and compare dmesg
warnings and oops counts. The future VM-specific tests use them heavily.
This patches relies on vm_ssh() already supporting namespaces.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
Changes in v11:
- break these out into an earlier patch so that they can be used
  directly in new patches (instead of causing churn by adding this
  later)
---
 tools/testing/selftests/vsock/vmtest.sh | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index c4d73dd0a4cf..4b5929ffc9eb 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -380,6 +380,17 @@ host_wait_for_listener() {
 	fi
 }
 
+vm_dmesg_oops_count() {
+	local ns=$1
+
+	vm_ssh "${ns}" -- dmesg 2>/dev/null | grep -c -i 'Oops'
+}
+
+vm_dmesg_warn_count() {
+	local ns=$1
+
+	vm_ssh "${ns}" -- dmesg --level=warn 2>/dev/null | grep -c -i 'vsock'
+}
 
 vm_vsock_test() {
 	local ns=$1
@@ -587,8 +598,8 @@ run_shared_vm_test() {
 
 	host_oops_cnt_before=$(dmesg | grep -c -i 'Oops')
 	host_warn_cnt_before=$(dmesg --level=warn | grep -c -i 'vsock')
-	vm_oops_cnt_before=$(vm_ssh "init_ns" -- dmesg | grep -c -i 'Oops')
-	vm_warn_cnt_before=$(vm_ssh "init_ns" -- dmesg --level=warn | grep -c -i 'vsock')
+	vm_oops_cnt_before=$(vm_dmesg_oops_count "init_ns")
+	vm_warn_cnt_before=$(vm_dmesg_warn_count "init_ns")
 
 	name=$(echo "${1}" | awk '{ print $1 }')
 	eval test_"${name}"
@@ -606,13 +617,13 @@ run_shared_vm_test() {
 		rc=$KSFT_FAIL
 	fi
 
-	vm_oops_cnt_after=$(vm_ssh "init_ns" -- dmesg | grep -i 'Oops' | wc -l)
+	vm_oops_cnt_after=$(vm_dmesg_oops_count "init_ns")
 	if [[ ${vm_oops_cnt_after} -gt ${vm_oops_cnt_before} ]]; then
 		echo "FAIL: kernel oops detected on vm" | log_host
 		rc=$KSFT_FAIL
 	fi
 
-	vm_warn_cnt_after=$(vm_ssh "init_ns" -- dmesg --level=warn | grep -c -i 'vsock')
+	vm_warn_cnt_after=$(vm_dmesg_warn_count "init_ns")
 	if [[ ${vm_warn_cnt_after} -gt ${vm_warn_cnt_before} ]]; then
 		echo "FAIL: kernel warning detected on vm" | log_host
 		rc=$KSFT_FAIL

-- 
2.47.3

[PATCH net-next v16 08/12] selftests/vsock: use ss to wait for listeners instead of /proc/net

[Bobby Eshleman]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Replace /proc/net parsing with ss(8) for detecting listening sockets in
wait_for_listener() functions and add support for TCP, VSOCK, and Unix
socket protocols.

The previous implementation parsed /proc/net/tcp using awk to detect
listening sockets, but this approach could not support vsock because
vsock does not export socket information to /proc/net/.

Instead, use ss so that we can detect listeners on tcp, vsock, and unix.

The protocol parameter is now required for all wait_for_listener family
functions (wait_for_listener, vm_wait_for_listener,
host_wait_for_listener) to explicitly specify which socket type to wait
for.

ss is added to the dependency check in check_deps().

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
 tools/testing/selftests/vsock/vmtest.sh | 47 +++++++++++++++++++++------------
 1 file changed, 30 insertions(+), 17 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index 4b5929ffc9eb..0e681d4c3a15 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -182,7 +182,7 @@ check_args() {
 }
 
 check_deps() {
-	for dep in vng ${QEMU} busybox pkill ssh; do
+	for dep in vng ${QEMU} busybox pkill ssh ss; do
 		if [[ ! -x $(command -v "${dep}") ]]; then
 			echo -e "skip:    dependency ${dep} not found!\n"
 			exit "${KSFT_SKIP}"
@@ -337,21 +337,32 @@ wait_for_listener()
 	local port=$1
 	local interval=$2
 	local max_intervals=$3
-	local protocol=tcp
-	local pattern
+	local protocol=$4
 	local i
 
-	pattern=":$(printf "%04X" "${port}") "
-
-	# for tcp protocol additionally check the socket state
-	[ "${protocol}" = "tcp" ] && pattern="${pattern}0A"
-
 	for i in $(seq "${max_intervals}"); do
-		if awk -v pattern="${pattern}" \
-			'BEGIN {rc=1} $2" "$4 ~ pattern {rc=0} END {exit rc}' \
-			/proc/net/"${protocol}"*; then
+		case "${protocol}" in
+		tcp)
+			if ss --listening --tcp --numeric | grep -q ":${port} "; then
+				break
+			fi
+			;;
+		vsock)
+			if ss --listening --vsock --numeric | grep -q ":${port} "; then
+				break
+			fi
+			;;
+		unix)
+			# For unix sockets, port is actually the socket path
+			if ss --listening --unix | grep -q "${port}"; then
+				break
+			fi
+			;;
+		*)
+			echo "Unknown protocol: ${protocol}" >&2
 			break
-		fi
+			;;
+		esac
 		sleep "${interval}"
 	done
 }
@@ -359,23 +370,25 @@ wait_for_listener()
 vm_wait_for_listener() {
 	local ns=$1
 	local port=$2
+	local protocol=$3
 
 	vm_ssh "${ns}" <<EOF
 $(declare -f wait_for_listener)
-wait_for_listener ${port} ${WAIT_PERIOD} ${WAIT_PERIOD_MAX}
+wait_for_listener ${port} ${WAIT_PERIOD} ${WAIT_PERIOD_MAX} ${protocol}
 EOF
 }
 
 host_wait_for_listener() {
 	local ns=$1
 	local port=$2
+	local protocol=$3
 
 	if [[ "${ns}" == "init_ns" ]]; then
-		wait_for_listener "${port}" "${WAIT_PERIOD}" "${WAIT_PERIOD_MAX}"
+		wait_for_listener "${port}" "${WAIT_PERIOD}" "${WAIT_PERIOD_MAX}" "${protocol}"
 	else
 		ip netns exec "${ns}" bash <<-EOF
 			$(declare -f wait_for_listener)
-			wait_for_listener ${port} ${WAIT_PERIOD} ${WAIT_PERIOD_MAX}
+			wait_for_listener ${port} ${WAIT_PERIOD} ${WAIT_PERIOD_MAX} ${protocol}
 		EOF
 	fi
 }
@@ -422,7 +435,7 @@ vm_vsock_test() {
 			return $rc
 		fi
 
-		vm_wait_for_listener "${ns}" "${port}"
+		vm_wait_for_listener "${ns}" "${port}" "tcp"
 		rc=$?
 	fi
 	set +o pipefail
@@ -463,7 +476,7 @@ host_vsock_test() {
 			return $rc
 		fi
 
-		host_wait_for_listener "${ns}" "${port}"
+		host_wait_for_listener "${ns}" "${port}" "tcp"
 		rc=$?
 	fi
 	set +o pipefail

-- 
2.47.3

[PATCH net-next v16 09/12] selftests/vsock: add tests for proc sys vsock ns_mode

[Bobby Eshleman]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Add tests for the /proc/sys/net/vsock/{ns_mode,child_ns_mode}
interfaces. Namely, that they accept/report "global" and "local" strings
and enforce their access policies.

Start a convention of commenting the test name over the test
description. Add test name comments over test descriptions that existed
before this convention.

Add a check_netns() function that checks if the test requires namespaces
and if the current kernel supports namespaces. Skip tests that require
namespaces if the system does not have namespace support.

This patch is the first to add tests that do *not* re-use the same
shared VM. For that reason, it adds a run_ns_tests() function to run
these tests and filter out the shared VM tests.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
Changes in v13:
- remove write-once test ns_host_vsock_ns_mode_write_once_ok to reflect
  removing the write-once policy
- add child_ns_mode test test_ns_host_vsock_child_ns_mode_ok
- modify test_ns_host_vsock_ns_mode_ok() to check that the correct mode
  was inherited from child_ns_mode

Changes in v12:
- remove ns_vm_local_mode_rejected test, due to dropping that constraint

Changes in v11:
- Document ns_ prefix above TEST_NAMES (Stefano)

Changes in v10:
- Remove extraneous add_namespaces/del_namespaces calls.
- Rename run_tests() to run_ns_tests() since it is designed to only
  run ns tests.

Changes in v9:
- add test ns_vm_local_mode_rejected to check that guests cannot use
  local mode
---
 tools/testing/selftests/vsock/vmtest.sh | 140 +++++++++++++++++++++++++++++++-
 1 file changed, 138 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index 0e681d4c3a15..38785a102236 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -41,14 +41,38 @@ readonly KERNEL_CMDLINE="\
 	virtme.ssh virtme_ssh_channel=tcp virtme_ssh_user=$USER \
 "
 readonly LOG=$(mktemp /tmp/vsock_vmtest_XXXX.log)
-readonly TEST_NAMES=(vm_server_host_client vm_client_host_server vm_loopback)
+
+# Namespace tests must use the ns_ prefix. This is checked in check_netns() and
+# is used to determine if a test needs namespace setup before test execution.
+readonly TEST_NAMES=(
+	vm_server_host_client
+	vm_client_host_server
+	vm_loopback
+	ns_host_vsock_ns_mode_ok
+	ns_host_vsock_child_ns_mode_ok
+)
 readonly TEST_DESCS=(
+	# vm_server_host_client
 	"Run vsock_test in server mode on the VM and in client mode on the host."
+
+	# vm_client_host_server
 	"Run vsock_test in client mode on the VM and in server mode on the host."
+
+	# vm_loopback
 	"Run vsock_test using the loopback transport in the VM."
+
+	# ns_host_vsock_ns_mode_ok
+	"Check /proc/sys/net/vsock/ns_mode strings on the host."
+
+	# ns_host_vsock_child_ns_mode_ok
+	"Check /proc/sys/net/vsock/ns_mode is read-only and child_ns_mode is writable."
 )
 
-readonly USE_SHARED_VM=(vm_server_host_client vm_client_host_server vm_loopback)
+readonly USE_SHARED_VM=(
+	vm_server_host_client
+	vm_client_host_server
+	vm_loopback
+)
 readonly NS_MODES=("local" "global")
 
 VERBOSE=0
@@ -196,6 +220,20 @@ check_deps() {
 	fi
 }
 
+check_netns() {
+	local tname=$1
+
+	# If the test requires NS support, check if NS support exists
+	# using /proc/self/ns
+	if [[ "${tname}" =~ ^ns_ ]] &&
+	   [[ ! -e /proc/self/ns ]]; then
+		log_host "No NS support detected for test ${tname}"
+		return 1
+	fi
+
+	return 0
+}
+
 check_vng() {
 	local tested_versions
 	local version
@@ -519,6 +557,54 @@ log_guest() {
 	LOG_PREFIX=guest log "$@"
 }
 
+ns_get_mode() {
+	local ns=$1
+
+	ip netns exec "${ns}" cat /proc/sys/net/vsock/ns_mode 2>/dev/null
+}
+
+test_ns_host_vsock_ns_mode_ok() {
+	for mode in "${NS_MODES[@]}"; do
+		local actual
+
+		actual=$(ns_get_mode "${mode}0")
+		if [[ "${actual}" != "${mode}" ]]; then
+			log_host "expected mode ${mode}, got ${actual}"
+			return "${KSFT_FAIL}"
+		fi
+	done
+
+	return "${KSFT_PASS}"
+}
+
+test_ns_host_vsock_child_ns_mode_ok() {
+	local orig_mode
+	local rc
+
+	orig_mode=$(cat /proc/sys/net/vsock/child_ns_mode)
+
+	rc="${KSFT_PASS}"
+	for mode in "${NS_MODES[@]}"; do
+		local ns="${mode}0"
+
+		if echo "${mode}" 2>/dev/null > /proc/sys/net/vsock/ns_mode; then
+			log_host "ns_mode should be read-only but write succeeded"
+			rc="${KSFT_FAIL}"
+			continue
+		fi
+
+		if ! echo "${mode}" > /proc/sys/net/vsock/child_ns_mode; then
+			log_host "child_ns_mode should be writable to ${mode}"
+			rc="${KSFT_FAIL}"
+			continue
+		fi
+	done
+
+	echo "${orig_mode}" > /proc/sys/net/vsock/child_ns_mode
+
+	return "${rc}"
+}
+
 test_vm_server_host_client() {
 	if ! vm_vsock_test "init_ns" "server" 2 "${TEST_GUEST_PORT}"; then
 		return "${KSFT_FAIL}"
@@ -592,6 +678,11 @@ run_shared_vm_tests() {
 			continue
 		fi
 
+		if ! check_netns "${arg}"; then
+			check_result "${KSFT_SKIP}" "${arg}"
+			continue
+		fi
+
 		run_shared_vm_test "${arg}"
 		check_result "$?" "${arg}"
 	done
@@ -645,6 +736,49 @@ run_shared_vm_test() {
 	return "${rc}"
 }
 
+run_ns_tests() {
+	for arg in "${ARGS[@]}"; do
+		if shared_vm_test "${arg}"; then
+			continue
+		fi
+
+		if ! check_netns "${arg}"; then
+			check_result "${KSFT_SKIP}" "${arg}"
+			continue
+		fi
+
+		add_namespaces
+
+		name=$(echo "${arg}" | awk '{ print $1 }')
+		log_host "Executing test_${name}"
+
+		host_oops_before=$(dmesg 2>/dev/null | grep -c -i 'Oops')
+		host_warn_before=$(dmesg --level=warn 2>/dev/null | grep -c -i 'vsock')
+		eval test_"${name}"
+		rc=$?
+
+		host_oops_after=$(dmesg 2>/dev/null | grep -c -i 'Oops')
+		if [[ "${host_oops_after}" -gt "${host_oops_before}" ]]; then
+			echo "FAIL: kernel oops detected on host" | log_host
+			check_result "${KSFT_FAIL}" "${name}"
+			del_namespaces
+			continue
+		fi
+
+		host_warn_after=$(dmesg --level=warn 2>/dev/null | grep -c -i 'vsock')
+		if [[ "${host_warn_after}" -gt "${host_warn_before}" ]]; then
+			echo "FAIL: kernel warning detected on host" | log_host
+			check_result "${KSFT_FAIL}" "${name}"
+			del_namespaces
+			continue
+		fi
+
+		check_result "${rc}" "${name}"
+
+		del_namespaces
+	done
+}
+
 BUILD=0
 QEMU="qemu-system-$(uname -m)"
 
@@ -690,6 +824,8 @@ if shared_vm_tests_requested "${ARGS[@]}"; then
 	terminate_pidfiles "${pidfile}"
 fi
 
+run_ns_tests "${ARGS[@]}"
+
 echo "SUMMARY: PASS=${cnt_pass} SKIP=${cnt_skip} FAIL=${cnt_fail}"
 echo "Log: ${LOG}"
 

-- 
2.47.3

[PATCH net-next v16 10/12] selftests/vsock: add namespace tests for CID collisions

[Bobby Eshleman]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Add tests to verify CID collision rules across different vsock namespace
modes.

1. Two VMs with the same CID cannot start in different global namespaces
   (ns_global_same_cid_fails)
2. Two VMs with the same CID can start in different local namespaces
   (ns_local_same_cid_ok)
3. VMs with the same CID can coexist when one is in a global namespace
   and another is in a local namespace (ns_global_local_same_cid_ok and
   ns_local_global_same_cid_ok)

The tests ns_global_local_same_cid_ok and ns_local_global_same_cid_ok
make sure that ordering does not matter.

The tests use a shared helper function namespaces_can_boot_same_cid()
that attempts to start two VMs with identical CIDs in the specified
namespaces and verifies whether VM initialization failed or succeeded.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
Changes in v11:
- check vm_start() rc in namespaces_can_boot_same_cid() (Stefano)
- fix ns_local_same_cid_ok() to use local0 and local1 instead of reusing
  local0 twice. This check should pass, ensuring local namespaces do not
  collide (Stefano)
---
 tools/testing/selftests/vsock/vmtest.sh | 78 +++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index 38785a102236..1bf537410ea6 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -50,6 +50,10 @@ readonly TEST_NAMES=(
 	vm_loopback
 	ns_host_vsock_ns_mode_ok
 	ns_host_vsock_child_ns_mode_ok
+	ns_global_same_cid_fails
+	ns_local_same_cid_ok
+	ns_global_local_same_cid_ok
+	ns_local_global_same_cid_ok
 )
 readonly TEST_DESCS=(
 	# vm_server_host_client
@@ -66,6 +70,18 @@ readonly TEST_DESCS=(
 
 	# ns_host_vsock_child_ns_mode_ok
 	"Check /proc/sys/net/vsock/ns_mode is read-only and child_ns_mode is writable."
+
+	# ns_global_same_cid_fails
+	"Check QEMU fails to start two VMs with same CID in two different global namespaces."
+
+	# ns_local_same_cid_ok
+	"Check QEMU successfully starts two VMs with same CID in two different local namespaces."
+
+	# ns_global_local_same_cid_ok
+	"Check QEMU successfully starts one VM in a global ns and then another VM in a local ns with the same CID."
+
+	# ns_local_global_same_cid_ok
+	"Check QEMU successfully starts one VM in a local ns and then another VM in a global ns with the same CID."
 )
 
 readonly USE_SHARED_VM=(
@@ -577,6 +593,68 @@ test_ns_host_vsock_ns_mode_ok() {
 	return "${KSFT_PASS}"
 }
 
+namespaces_can_boot_same_cid() {
+	local ns0=$1
+	local ns1=$2
+	local pidfile1 pidfile2
+	local rc
+
+	pidfile1="$(create_pidfile)"
+
+	# The first VM should be able to start. If it can't then we have
+	# problems and need to return non-zero.
+	if ! vm_start "${pidfile1}" "${ns0}"; then
+		return 1
+	fi
+
+	pidfile2="$(create_pidfile)"
+	vm_start "${pidfile2}" "${ns1}"
+	rc=$?
+	terminate_pidfiles "${pidfile1}" "${pidfile2}"
+
+	return "${rc}"
+}
+
+test_ns_global_same_cid_fails() {
+	init_namespaces
+
+	if namespaces_can_boot_same_cid "global0" "global1"; then
+		return "${KSFT_FAIL}"
+	fi
+
+	return "${KSFT_PASS}"
+}
+
+test_ns_local_global_same_cid_ok() {
+	init_namespaces
+
+	if namespaces_can_boot_same_cid "local0" "global0"; then
+		return "${KSFT_PASS}"
+	fi
+
+	return "${KSFT_FAIL}"
+}
+
+test_ns_global_local_same_cid_ok() {
+	init_namespaces
+
+	if namespaces_can_boot_same_cid "global0" "local0"; then
+		return "${KSFT_PASS}"
+	fi
+
+	return "${KSFT_FAIL}"
+}
+
+test_ns_local_same_cid_ok() {
+	init_namespaces
+
+	if namespaces_can_boot_same_cid "local0" "local1"; then
+		return "${KSFT_PASS}"
+	fi
+
+	return "${KSFT_FAIL}"
+}
+
 test_ns_host_vsock_child_ns_mode_ok() {
 	local orig_mode
 	local rc

-- 
2.47.3

[PATCH net-next v16 11/12] selftests/vsock: add tests for host <-> vm connectivity with namespaces

[Bobby Eshleman]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Add tests to validate namespace correctness using vsock_test and socat.
The vsock_test tool is used to validate expected success tests, but
socat is used for expected failure tests. socat is used to ensure that
connections are rejected outright instead of failing due to some other
socket behavior (as tested in vsock_test). Additionally, socat is
already required for tunneling TCP traffic from vsock_test. Using only
one of the vsock_test tests like 'test_stream_client_close_client' would
have yielded a similar result, but doing so wouldn't remove the socat
dependency.

Additionally, check for the dependency socat. socat needs special
handling beyond just checking if it is on the path because it must be
compiled with support for both vsock and unix. The function
check_socat() checks that this support exists.

Add more padding to test name printf strings because the tests added in
this patch would otherwise overflow.

Add vm_dmesg_* helpers to encapsulate checking dmesg
for oops and warnings.

Add ability to pass extra args to host-side vsock_test so that tests
that cause false positives may be skipped with arg --skip.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
Changes in v12:
- add test skip (vsock_test test 29) when host_vsock_test() uses client
  mode in a local namespace. Test 29 causes a false positive to trigger.

Changes in v11:
- add 'sleep "${WAIT_PERIOD}"' after any non-TCP socat LISTEN cmd
  (Stefano)
- add host_wait_for_listener() after any socat TCP-LISTEN (Stefano)
- reuse vm_dmesg_{oops,warn}_count() inside vm_dmesg_check()
- fix copy-paste in test_ns_same_local_vm_connect_to_local_host_ok()
  (Stefano)

Changes in v10:
- add vm_dmesg_start() and vm_dmesg_check()

Changes in v9:
- consistent variable quoting
---
 tools/testing/selftests/vsock/vmtest.sh | 572 +++++++++++++++++++++++++++++++-
 1 file changed, 568 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index 1bf537410ea6..a9eaf37bc31b 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -7,6 +7,7 @@
 #		* virtme-ng
 #		* busybox-static (used by virtme-ng)
 #		* qemu	(used by virtme-ng)
+#		* socat
 #
 # shellcheck disable=SC2317,SC2119
 
@@ -54,6 +55,19 @@ readonly TEST_NAMES=(
 	ns_local_same_cid_ok
 	ns_global_local_same_cid_ok
 	ns_local_global_same_cid_ok
+	ns_diff_global_host_connect_to_global_vm_ok
+	ns_diff_global_host_connect_to_local_vm_fails
+	ns_diff_global_vm_connect_to_global_host_ok
+	ns_diff_global_vm_connect_to_local_host_fails
+	ns_diff_local_host_connect_to_local_vm_fails
+	ns_diff_local_vm_connect_to_local_host_fails
+	ns_diff_global_to_local_loopback_local_fails
+	ns_diff_local_to_global_loopback_fails
+	ns_diff_local_to_local_loopback_fails
+	ns_diff_global_to_global_loopback_ok
+	ns_same_local_loopback_ok
+	ns_same_local_host_connect_to_local_vm_ok
+	ns_same_local_vm_connect_to_local_host_ok
 )
 readonly TEST_DESCS=(
 	# vm_server_host_client
@@ -82,6 +96,45 @@ readonly TEST_DESCS=(
 
 	# ns_local_global_same_cid_ok
 	"Check QEMU successfully starts one VM in a local ns and then another VM in a global ns with the same CID."
+
+	# ns_diff_global_host_connect_to_global_vm_ok
+	"Run vsock_test client in global ns with server in VM in another global ns."
+
+	# ns_diff_global_host_connect_to_local_vm_fails
+	"Run socat to test a process in a global ns fails to connect to a VM in a local ns."
+
+	# ns_diff_global_vm_connect_to_global_host_ok
+	"Run vsock_test client in VM in a global ns with server in another global ns."
+
+	# ns_diff_global_vm_connect_to_local_host_fails
+	"Run socat to test a VM in a global ns fails to connect to a host process in a local ns."
+
+	# ns_diff_local_host_connect_to_local_vm_fails
+	"Run socat to test a host process in a local ns fails to connect to a VM in another local ns."
+
+	# ns_diff_local_vm_connect_to_local_host_fails
+	"Run socat to test a VM in a local ns fails to connect to a host process in another local ns."
+
+	# ns_diff_global_to_local_loopback_local_fails
+	"Run socat to test a loopback vsock in a global ns fails to connect to a vsock in a local ns."
+
+	# ns_diff_local_to_global_loopback_fails
+	"Run socat to test a loopback vsock in a local ns fails to connect to a vsock in a global ns."
+
+	# ns_diff_local_to_local_loopback_fails
+	"Run socat to test a loopback vsock in a local ns fails to connect to a vsock in another local ns."
+
+	# ns_diff_global_to_global_loopback_ok
+	"Run socat to test a loopback vsock in a global ns successfully connects to a vsock in another global ns."
+
+	# ns_same_local_loopback_ok
+	"Run socat to test a loopback vsock in a local ns successfully connects to a vsock in the same ns."
+
+	# ns_same_local_host_connect_to_local_vm_ok
+	"Run vsock_test client in a local ns with server in VM in same ns."
+
+	# ns_same_local_vm_connect_to_local_host_ok
+	"Run vsock_test client in VM in a local ns with server in same ns."
 )
 
 readonly USE_SHARED_VM=(
@@ -112,7 +165,7 @@ usage() {
 	for ((i = 0; i < ${#TEST_NAMES[@]}; i++)); do
 		name=${TEST_NAMES[${i}]}
 		desc=${TEST_DESCS[${i}]}
-		printf "\t%-35s%-35s\n" "${name}" "${desc}"
+		printf "\t%-55s%-35s\n" "${name}" "${desc}"
 	done
 	echo
 
@@ -222,7 +275,7 @@ check_args() {
 }
 
 check_deps() {
-	for dep in vng ${QEMU} busybox pkill ssh ss; do
+	for dep in vng ${QEMU} busybox pkill ssh ss socat; do
 		if [[ ! -x $(command -v "${dep}") ]]; then
 			echo -e "skip:    dependency ${dep} not found!\n"
 			exit "${KSFT_SKIP}"
@@ -273,6 +326,20 @@ check_vng() {
 	fi
 }
 
+check_socat() {
+	local support_string
+
+	support_string="$(socat -V)"
+
+	if [[ "${support_string}" != *"WITH_VSOCK 1"* ]]; then
+		die "err: socat is missing vsock support"
+	fi
+
+	if [[ "${support_string}" != *"WITH_UNIX 1"* ]]; then
+		die "err: socat is missing unix support"
+	fi
+}
+
 handle_build() {
 	if [[ ! "${BUILD}" -eq 1 ]]; then
 		return
@@ -321,6 +388,14 @@ terminate_pidfiles() {
 	done
 }
 
+terminate_pids() {
+	local pid
+
+	for pid in "$@"; do
+		kill -SIGTERM "${pid}" &>/dev/null || :
+	done
+}
+
 vm_start() {
 	local pidfile=$1
 	local ns=$2
@@ -459,6 +534,28 @@ vm_dmesg_warn_count() {
 	vm_ssh "${ns}" -- dmesg --level=warn 2>/dev/null | grep -c -i 'vsock'
 }
 
+vm_dmesg_check() {
+	local pidfile=$1
+	local ns=$2
+	local oops_before=$3
+	local warn_before=$4
+	local oops_after warn_after
+
+	oops_after=$(vm_dmesg_oops_count "${ns}")
+	if [[ "${oops_after}" -gt "${oops_before}" ]]; then
+		echo "FAIL: kernel oops detected on vm in ns ${ns}" | log_host
+		return 1
+	fi
+
+	warn_after=$(vm_dmesg_warn_count "${ns}")
+	if [[ "${warn_after}" -gt "${warn_before}" ]]; then
+		echo "FAIL: kernel warning detected on vm in ns ${ns}" | log_host
+		return 1
+	fi
+
+	return 0
+}
+
 vm_vsock_test() {
 	local ns=$1
 	local host=$2
@@ -502,6 +599,8 @@ host_vsock_test() {
 	local host=$2
 	local cid=$3
 	local port=$4
+	shift 4
+	local extra_args=("$@")
 	local rc
 
 	local cmd="${VSOCK_TEST}"
@@ -516,13 +615,15 @@ host_vsock_test() {
 			--mode=client \
 			--peer-cid="${cid}" \
 			--control-host="${host}" \
-			--control-port="${port}" 2>&1 | log_host
+			--control-port="${port}" \
+			"${extra_args[@]}" 2>&1 | log_host
 		rc=$?
 	else
 		${cmd} \
 			--mode=server \
 			--peer-cid="${cid}" \
-			--control-port="${port}" 2>&1 | log_host &
+			--control-port="${port}" \
+			"${extra_args[@]}" 2>&1 | log_host &
 		rc=$?
 
 		if [[ $rc -ne 0 ]]; then
@@ -593,6 +694,468 @@ test_ns_host_vsock_ns_mode_ok() {
 	return "${KSFT_PASS}"
 }
 
+test_ns_diff_global_host_connect_to_global_vm_ok() {
+	local oops_before warn_before
+	local pids pid pidfile
+	local ns0 ns1 port
+	declare -a pids
+	local unixfile
+	ns0="global0"
+	ns1="global1"
+	port=1234
+	local rc
+
+	init_namespaces
+
+	pidfile="$(create_pidfile)"
+
+	if ! vm_start "${pidfile}" "${ns0}"; then
+		return "${KSFT_FAIL}"
+	fi
+
+	vm_wait_for_ssh "${ns0}"
+	oops_before=$(vm_dmesg_oops_count "${ns0}")
+	warn_before=$(vm_dmesg_warn_count "${ns0}")
+
+	unixfile=$(mktemp -u /tmp/XXXX.sock)
+	ip netns exec "${ns1}" \
+		socat TCP-LISTEN:"${TEST_HOST_PORT}",fork \
+			UNIX-CONNECT:"${unixfile}" &
+	pids+=($!)
+	host_wait_for_listener "${ns1}" "${TEST_HOST_PORT}" "tcp"
+
+	ip netns exec "${ns0}" socat UNIX-LISTEN:"${unixfile}",fork \
+		TCP-CONNECT:localhost:"${TEST_HOST_PORT}" &
+	pids+=($!)
+	host_wait_for_listener "${ns0}" "${unixfile}" "unix"
+
+	vm_vsock_test "${ns0}" "server" 2 "${TEST_GUEST_PORT}"
+	vm_wait_for_listener "${ns0}" "${TEST_GUEST_PORT}" "tcp"
+	host_vsock_test "${ns1}" "127.0.0.1" "${VSOCK_CID}" "${TEST_HOST_PORT}"
+	rc=$?
+
+	vm_dmesg_check "${pidfile}" "${ns0}" "${oops_before}" "${warn_before}"
+	dmesg_rc=$?
+
+	terminate_pids "${pids[@]}"
+	terminate_pidfiles "${pidfile}"
+
+	if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then
+		return "${KSFT_FAIL}"
+	fi
+
+	return "${KSFT_PASS}"
+}
+
+test_ns_diff_global_host_connect_to_local_vm_fails() {
+	local oops_before warn_before
+	local ns0="global0"
+	local ns1="local0"
+	local port=12345
+	local dmesg_rc
+	local pidfile
+	local result
+	local pid
+
+	init_namespaces
+
+	outfile=$(mktemp)
+
+	pidfile="$(create_pidfile)"
+	if ! vm_start "${pidfile}" "${ns1}"; then
+		log_host "failed to start vm (cid=${VSOCK_CID}, ns=${ns0})"
+		return "${KSFT_FAIL}"
+	fi
+
+	vm_wait_for_ssh "${ns1}"
+	oops_before=$(vm_dmesg_oops_count "${ns1}")
+	warn_before=$(vm_dmesg_warn_count "${ns1}")
+
+	vm_ssh "${ns1}" -- socat VSOCK-LISTEN:"${port}" STDOUT > "${outfile}" &
+	vm_wait_for_listener "${ns1}" "${port}" "vsock"
+	echo TEST | ip netns exec "${ns0}" \
+		socat STDIN VSOCK-CONNECT:"${VSOCK_CID}":"${port}" 2>/dev/null
+
+	vm_dmesg_check "${pidfile}" "${ns1}" "${oops_before}" "${warn_before}"
+	dmesg_rc=$?
+
+	terminate_pidfiles "${pidfile}"
+	result=$(cat "${outfile}")
+	rm -f "${outfile}"
+
+	if [[ "${result}" == "TEST" ]] || [[ "${dmesg_rc}" -ne 0 ]]; then
+		return "${KSFT_FAIL}"
+	fi
+
+	return "${KSFT_PASS}"
+}
+
+test_ns_diff_global_vm_connect_to_global_host_ok() {
+	local oops_before warn_before
+	local ns0="global0"
+	local ns1="global1"
+	local port=12345
+	local unixfile
+	local dmesg_rc
+	local pidfile
+	local pids
+	local rc
+
+	init_namespaces
+
+	declare -a pids
+
+	log_host "Setup socat bridge from ns ${ns0} to ns ${ns1} over port ${port}"
+
+	unixfile=$(mktemp -u /tmp/XXXX.sock)
+
+	ip netns exec "${ns0}" \
+		socat TCP-LISTEN:"${port}" UNIX-CONNECT:"${unixfile}" &
+	pids+=($!)
+	host_wait_for_listener "${ns0}" "${port}" "tcp"
+
+	ip netns exec "${ns1}" \
+		socat UNIX-LISTEN:"${unixfile}" TCP-CONNECT:127.0.0.1:"${port}" &
+	pids+=($!)
+	host_wait_for_listener "${ns1}" "${unixfile}" "unix"
+
+	log_host "Launching ${VSOCK_TEST} in ns ${ns1}"
+	host_vsock_test "${ns1}" "server" "${VSOCK_CID}" "${port}"
+
+	pidfile="$(create_pidfile)"
+	if ! vm_start "${pidfile}" "${ns0}"; then
+		log_host "failed to start vm (cid=${cid}, ns=${ns0})"
+		terminate_pids "${pids[@]}"
+		rm -f "${unixfile}"
+		return "${KSFT_FAIL}"
+	fi
+
+	vm_wait_for_ssh "${ns0}"
+
+	oops_before=$(vm_dmesg_oops_count "${ns0}")
+	warn_before=$(vm_dmesg_warn_count "${ns0}")
+
+	vm_vsock_test "${ns0}" "10.0.2.2" 2 "${port}"
+	rc=$?
+
+	vm_dmesg_check "${pidfile}" "${ns0}" "${oops_before}" "${warn_before}"
+	dmesg_rc=$?
+
+	terminate_pidfiles "${pidfile}"
+	terminate_pids "${pids[@]}"
+	rm -f "${unixfile}"
+
+	if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then
+		return "${KSFT_FAIL}"
+	fi
+
+	return "${KSFT_PASS}"
+
+}
+
+test_ns_diff_global_vm_connect_to_local_host_fails() {
+	local ns0="global0"
+	local ns1="local0"
+	local port=12345
+	local oops_before warn_before
+	local dmesg_rc
+	local pidfile
+	local result
+	local pid
+
+	init_namespaces
+
+	log_host "Launching socat in ns ${ns1}"
+	outfile=$(mktemp)
+
+	ip netns exec "${ns1}" socat VSOCK-LISTEN:"${port}" STDOUT &> "${outfile}" &
+	pid=$!
+	host_wait_for_listener "${ns1}" "${port}" "vsock"
+
+	pidfile="$(create_pidfile)"
+	if ! vm_start "${pidfile}" "${ns0}"; then
+		log_host "failed to start vm (cid=${cid}, ns=${ns0})"
+		terminate_pids "${pid}"
+		rm -f "${outfile}"
+		return "${KSFT_FAIL}"
+	fi
+
+	vm_wait_for_ssh "${ns0}"
+
+	oops_before=$(vm_dmesg_oops_count "${ns0}")
+	warn_before=$(vm_dmesg_warn_count "${ns0}")
+
+	vm_ssh "${ns0}" -- \
+		bash -c "echo TEST | socat STDIN VSOCK-CONNECT:2:${port}" 2>&1 | log_guest
+
+	vm_dmesg_check "${pidfile}" "${ns0}" "${oops_before}" "${warn_before}"
+	dmesg_rc=$?
+
+	terminate_pidfiles "${pidfile}"
+	terminate_pids "${pid}"
+
+	result=$(cat "${outfile}")
+	rm -f "${outfile}"
+
+	if [[ "${result}" != TEST ]] && [[ "${dmesg_rc}" -eq 0 ]]; then
+		return "${KSFT_PASS}"
+	fi
+
+	return "${KSFT_FAIL}"
+}
+
+test_ns_diff_local_host_connect_to_local_vm_fails() {
+	local ns0="local0"
+	local ns1="local1"
+	local port=12345
+	local oops_before warn_before
+	local dmesg_rc
+	local pidfile
+	local result
+	local pid
+
+	init_namespaces
+
+	outfile=$(mktemp)
+
+	pidfile="$(create_pidfile)"
+	if ! vm_start "${pidfile}" "${ns1}"; then
+		log_host "failed to start vm (cid=${cid}, ns=${ns0})"
+		return "${KSFT_FAIL}"
+	fi
+
+	vm_wait_for_ssh "${ns1}"
+	oops_before=$(vm_dmesg_oops_count "${ns1}")
+	warn_before=$(vm_dmesg_warn_count "${ns1}")
+
+	vm_ssh "${ns1}" -- socat VSOCK-LISTEN:"${port}" STDOUT > "${outfile}" &
+	vm_wait_for_listener "${ns1}" "${port}" "vsock"
+
+	echo TEST | ip netns exec "${ns0}" \
+		socat STDIN VSOCK-CONNECT:"${VSOCK_CID}":"${port}" 2>/dev/null
+
+	vm_dmesg_check "${pidfile}" "${ns1}" "${oops_before}" "${warn_before}"
+	dmesg_rc=$?
+
+	terminate_pidfiles "${pidfile}"
+
+	result=$(cat "${outfile}")
+	rm -f "${outfile}"
+
+	if [[ "${result}" != TEST ]] && [[ "${dmesg_rc}" -eq 0 ]]; then
+		return "${KSFT_PASS}"
+	fi
+
+	return "${KSFT_FAIL}"
+}
+
+test_ns_diff_local_vm_connect_to_local_host_fails() {
+	local oops_before warn_before
+	local ns0="local0"
+	local ns1="local1"
+	local port=12345
+	local dmesg_rc
+	local pidfile
+	local result
+	local pid
+
+	init_namespaces
+
+	log_host "Launching socat in ns ${ns1}"
+	outfile=$(mktemp)
+	ip netns exec "${ns1}" socat VSOCK-LISTEN:"${port}" STDOUT &> "${outfile}" &
+	pid=$!
+	host_wait_for_listener "${ns1}" "${port}" "vsock"
+
+	pidfile="$(create_pidfile)"
+	if ! vm_start "${pidfile}" "${ns0}"; then
+		log_host "failed to start vm (cid=${cid}, ns=${ns0})"
+		rm -f "${outfile}"
+		return "${KSFT_FAIL}"
+	fi
+
+	vm_wait_for_ssh "${ns0}"
+	oops_before=$(vm_dmesg_oops_count "${ns0}")
+	warn_before=$(vm_dmesg_warn_count "${ns0}")
+
+	vm_ssh "${ns0}" -- \
+		bash -c "echo TEST | socat STDIN VSOCK-CONNECT:2:${port}" 2>&1 | log_guest
+
+	vm_dmesg_check "${pidfile}" "${ns0}" "${oops_before}" "${warn_before}"
+	dmesg_rc=$?
+
+	terminate_pidfiles "${pidfile}"
+	terminate_pids "${pid}"
+
+	result=$(cat "${outfile}")
+	rm -f "${outfile}"
+
+	if [[ "${result}" != TEST ]] && [[ "${dmesg_rc}" -eq 0 ]]; then
+		return "${KSFT_PASS}"
+	fi
+
+	return "${KSFT_FAIL}"
+}
+
+__test_loopback_two_netns() {
+	local ns0=$1
+	local ns1=$2
+	local port=12345
+	local result
+	local pid
+
+	modprobe vsock_loopback &> /dev/null || :
+
+	log_host "Launching socat in ns ${ns1}"
+	outfile=$(mktemp)
+
+	ip netns exec "${ns1}" socat VSOCK-LISTEN:"${port}" STDOUT > "${outfile}" 2>/dev/null &
+	pid=$!
+	host_wait_for_listener "${ns1}" "${port}" "vsock"
+
+	log_host "Launching socat in ns ${ns0}"
+	echo TEST | ip netns exec "${ns0}" socat STDIN VSOCK-CONNECT:1:"${port}" 2>/dev/null
+	terminate_pids "${pid}"
+
+	result=$(cat "${outfile}")
+	rm -f "${outfile}"
+
+	if [[ "${result}" == TEST ]]; then
+		return 0
+	fi
+
+	return 1
+}
+
+test_ns_diff_global_to_local_loopback_local_fails() {
+	init_namespaces
+
+	if ! __test_loopback_two_netns "global0" "local0"; then
+		return "${KSFT_PASS}"
+	fi
+
+	return "${KSFT_FAIL}"
+}
+
+test_ns_diff_local_to_global_loopback_fails() {
+	init_namespaces
+
+	if ! __test_loopback_two_netns "local0" "global0"; then
+		return "${KSFT_PASS}"
+	fi
+
+	return "${KSFT_FAIL}"
+}
+
+test_ns_diff_local_to_local_loopback_fails() {
+	init_namespaces
+
+	if ! __test_loopback_two_netns "local0" "local1"; then
+		return "${KSFT_PASS}"
+	fi
+
+	return "${KSFT_FAIL}"
+}
+
+test_ns_diff_global_to_global_loopback_ok() {
+	init_namespaces
+
+	if __test_loopback_two_netns "global0" "global1"; then
+		return "${KSFT_PASS}"
+	fi
+
+	return "${KSFT_FAIL}"
+}
+
+test_ns_same_local_loopback_ok() {
+	init_namespaces
+
+	if __test_loopback_two_netns "local0" "local0"; then
+		return "${KSFT_PASS}"
+	fi
+
+	return "${KSFT_FAIL}"
+}
+
+test_ns_same_local_host_connect_to_local_vm_ok() {
+	local oops_before warn_before
+	local ns="local0"
+	local port=1234
+	local dmesg_rc
+	local pidfile
+	local rc
+
+	init_namespaces
+
+	pidfile="$(create_pidfile)"
+
+	if ! vm_start "${pidfile}" "${ns}"; then
+		return "${KSFT_FAIL}"
+	fi
+
+	vm_wait_for_ssh "${ns}"
+	oops_before=$(vm_dmesg_oops_count "${ns}")
+	warn_before=$(vm_dmesg_warn_count "${ns}")
+
+	vm_vsock_test "${ns}" "server" 2 "${TEST_GUEST_PORT}"
+
+	# Skip test 29 (transport release use-after-free): This test attempts
+	# binding both G2H and H2G CIDs. Because virtio-vsock (G2H) doesn't
+	# support local namespaces the test will fail when
+	# transport_g2h->stream_allow() returns false. This edge case only
+	# happens for vsock_test in client mode on the host in a local
+	# namespace. This is a false positive.
+	host_vsock_test "${ns}" "127.0.0.1" "${VSOCK_CID}" "${TEST_HOST_PORT}" --skip=29
+	rc=$?
+
+	vm_dmesg_check "${pidfile}" "${ns}" "${oops_before}" "${warn_before}"
+	dmesg_rc=$?
+
+	terminate_pidfiles "${pidfile}"
+
+	if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then
+		return "${KSFT_FAIL}"
+	fi
+
+	return "${KSFT_PASS}"
+}
+
+test_ns_same_local_vm_connect_to_local_host_ok() {
+	local oops_before warn_before
+	local ns="local0"
+	local port=1234
+	local dmesg_rc
+	local pidfile
+	local rc
+
+	init_namespaces
+
+	pidfile="$(create_pidfile)"
+
+	if ! vm_start "${pidfile}" "${ns}"; then
+		return "${KSFT_FAIL}"
+	fi
+
+	vm_wait_for_ssh "${ns}"
+	oops_before=$(vm_dmesg_oops_count "${ns}")
+	warn_before=$(vm_dmesg_warn_count "${ns}")
+
+	host_vsock_test "${ns}" "server" "${VSOCK_CID}" "${port}"
+	vm_vsock_test "${ns}" "10.0.2.2" 2 "${port}"
+	rc=$?
+
+	vm_dmesg_check "${pidfile}" "${ns}" "${oops_before}" "${warn_before}"
+	dmesg_rc=$?
+
+	terminate_pidfiles "${pidfile}"
+
+	if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then
+		return "${KSFT_FAIL}"
+	fi
+
+	return "${KSFT_PASS}"
+}
+
 namespaces_can_boot_same_cid() {
 	local ns0=$1
 	local ns1=$2
@@ -882,6 +1445,7 @@ fi
 check_args "${ARGS[@]}"
 check_deps
 check_vng
+check_socat
 handle_build
 
 echo "1..${#ARGS[@]}"

-- 
2.47.3

[PATCH net-next v16 12/12] selftests/vsock: add tests for namespace deletion

[Bobby Eshleman]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Add tests that validate vsock sockets are resilient to deleting
namespaces. The vsock sockets should still function normally.

The function check_ns_delete_doesnt_break_connection() is added to
re-use the step-by-step logic of 1) setup connections, 2) delete ns,
3) check that the connections are still ok.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
Changes in v13:
- remove tests that change the mode after socket creation (this is not
  supported behavior now and the immutability property is tested in other
  tests)
- remove "change_mode" behavior of
  check_ns_changes_dont_break_connection() and rename to
  check_ns_delete_doesnt_break_connection() because we only need to test
  namespace deletion (other tests confirm that the mode cannot change)

Changes in v11:
- remove pipefile (Stefano)

Changes in v9:
- more consistent shell style
- clarify -u usage comment for pipefile
---
 tools/testing/selftests/vsock/vmtest.sh | 84 +++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index a9eaf37bc31b..dc8dbe74a6d0 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -68,6 +68,9 @@ readonly TEST_NAMES=(
 	ns_same_local_loopback_ok
 	ns_same_local_host_connect_to_local_vm_ok
 	ns_same_local_vm_connect_to_local_host_ok
+	ns_delete_vm_ok
+	ns_delete_host_ok
+	ns_delete_both_ok
 )
 readonly TEST_DESCS=(
 	# vm_server_host_client
@@ -135,6 +138,15 @@ readonly TEST_DESCS=(
 
 	# ns_same_local_vm_connect_to_local_host_ok
 	"Run vsock_test client in VM in a local ns with server in same ns."
+
+	# ns_delete_vm_ok
+	"Check that deleting the VM's namespace does not break the socket connection"
+
+	# ns_delete_host_ok
+	"Check that deleting the host's namespace does not break the socket connection"
+
+	# ns_delete_both_ok
+	"Check that deleting the VM and host's namespaces does not break the socket connection"
 )
 
 readonly USE_SHARED_VM=(
@@ -1287,6 +1299,78 @@ test_vm_loopback() {
 	return "${KSFT_PASS}"
 }
 
+check_ns_delete_doesnt_break_connection() {
+	local pipefile pidfile outfile
+	local ns0="global0"
+	local ns1="global1"
+	local port=12345
+	local pids=()
+	local rc=0
+
+	init_namespaces
+
+	pidfile="$(create_pidfile)"
+	if ! vm_start "${pidfile}" "${ns0}"; then
+		return "${KSFT_FAIL}"
+	fi
+	vm_wait_for_ssh "${ns0}"
+
+	outfile=$(mktemp)
+	vm_ssh "${ns0}" -- \
+		socat VSOCK-LISTEN:"${port}",fork STDOUT > "${outfile}" 2>/dev/null &
+	pids+=($!)
+	vm_wait_for_listener "${ns0}" "${port}" "vsock"
+
+	# We use a pipe here so that we can echo into the pipe instead of using
+	# socat and a unix socket file. We just need a name for the pipe (not a
+	# regular file) so use -u.
+	pipefile=$(mktemp -u /tmp/vmtest_pipe_XXXX)
+	ip netns exec "${ns1}" \
+		socat PIPE:"${pipefile}" VSOCK-CONNECT:"${VSOCK_CID}":"${port}" &
+	pids+=($!)
+
+	timeout "${WAIT_PERIOD}" \
+		bash -c 'while [[ ! -e '"${pipefile}"' ]]; do sleep 1; done; exit 0'
+
+	if [[ "$1" == "vm" ]]; then
+		ip netns del "${ns0}"
+	elif [[ "$1" == "host" ]]; then
+		ip netns del "${ns1}"
+	elif [[ "$1" == "both" ]]; then
+		ip netns del "${ns0}"
+		ip netns del "${ns1}"
+	fi
+
+	echo "TEST" > "${pipefile}"
+
+	timeout "${WAIT_PERIOD}" \
+		bash -c 'while [[ ! -s '"${outfile}"' ]]; do sleep 1; done; exit 0'
+
+	if grep -q "TEST" "${outfile}"; then
+		rc="${KSFT_PASS}"
+	else
+		rc="${KSFT_FAIL}"
+	fi
+
+	terminate_pidfiles "${pidfile}"
+	terminate_pids "${pids[@]}"
+	rm -f "${outfile}" "${pipefile}"
+
+	return "${rc}"
+}
+
+test_ns_delete_vm_ok() {
+	check_ns_delete_doesnt_break_connection "vm"
+}
+
+test_ns_delete_host_ok() {
+	check_ns_delete_doesnt_break_connection "host"
+}
+
+test_ns_delete_both_ok() {
+	check_ns_delete_doesnt_break_connection "both"
+}
+
 shared_vm_test() {
 	local tname
 

-- 
2.47.3

Re: [PATCH net-next v16 00/12] vsock: add namespace support to vhost-vsock and loopback

[Stefano Garzarella]

On Wed, Jan 21, 2026 at 02:11:40PM -0800, Bobby Eshleman wrote:
>This series adds namespace support to vhost-vsock and loopback. It does
>not add namespaces to any of the other guest transports (virtio-vsock,
>hyperv, or vmci).
>
>The current revision supports two modes: local and global. Local
>mode is complete isolation of namespaces, while global mode is complete
>sharing between namespaces of CIDs (the original behavior).
>
>The mode is set using the parent namespace's
>/proc/sys/net/vsock/child_ns_mode and inherited when a new namespace is
>created. The mode of the current namespace can be queried by reading
>/proc/sys/net/vsock/ns_mode. The mode can not change after the namespace
>has been created.
>
>Modes are per-netns. This allows a system to configure namespaces
>independently (some may share CIDs, others are completely isolated).
>This also supports future possible mixed use cases, where there may be
>namespaces in global mode spinning up VMs while there are mixed mode
>namespaces that provide services to the VMs, but are not allowed to
>allocate from the global CID pool (this mode is not implemented in this
>series).
>
>Additionally, added tests for the new namespace features:
>
>tools/testing/selftests/vsock/vmtest.sh
>1..25
>ok 1 vm_server_host_client
>ok 2 vm_client_host_server
>ok 3 vm_loopback
>ok 4 ns_host_vsock_ns_mode_ok
>ok 5 ns_host_vsock_child_ns_mode_ok
>ok 6 ns_global_same_cid_fails
>ok 7 ns_local_same_cid_ok
>ok 8 ns_global_local_same_cid_ok
>ok 9 ns_local_global_same_cid_ok
>ok 10 ns_diff_global_host_connect_to_global_vm_ok
>ok 11 ns_diff_global_host_connect_to_local_vm_fails
>ok 12 ns_diff_global_vm_connect_to_global_host_ok
>ok 13 ns_diff_global_vm_connect_to_local_host_fails
>ok 14 ns_diff_local_host_connect_to_local_vm_fails
>ok 15 ns_diff_local_vm_connect_to_local_host_fails
>ok 16 ns_diff_global_to_local_loopback_local_fails
>ok 17 ns_diff_local_to_global_loopback_fails
>ok 18 ns_diff_local_to_local_loopback_fails
>ok 19 ns_diff_global_to_global_loopback_ok
>ok 20 ns_same_local_loopback_ok
>ok 21 ns_same_local_host_connect_to_local_vm_ok
>ok 22 ns_same_local_vm_connect_to_local_host_ok
>ok 23 ns_delete_vm_ok
>ok 24 ns_delete_host_ok
>ok 25 ns_delete_both_ok
>SUMMARY: PASS=25 SKIP=0 FAIL=0
>
>Thanks again for everyone's help and reviews!

Thank you for your hard work and patience!

I think we've come up with an excellent solution that's also not too 
invasive.

All the patches have my R-b, I've double-checked and tested this v16.
Everything seems to be working fine (famous last words xD).

So this series is good to go IMO!

Next step should be to update the vsock(7) namespace.

Thanks,
Stefano

Re: [PATCH net-next v16 00/12] vsock: add namespace support to vhost-vsock and loopback

[Bobby Eshleman]

On Thu, Jan 22, 2026 at 02:55:36PM +0100, Stefano Garzarella wrote:
> On Wed, Jan 21, 2026 at 02:11:40PM -0800, Bobby Eshleman wrote:
> > This series adds namespace support to vhost-vsock and loopback. It does
> > not add namespaces to any of the other guest transports (virtio-vsock,
> > hyperv, or vmci).
> > 
> > The current revision supports two modes: local and global. Local
> > mode is complete isolation of namespaces, while global mode is complete
> > sharing between namespaces of CIDs (the original behavior).
> > 
> > The mode is set using the parent namespace's
> > /proc/sys/net/vsock/child_ns_mode and inherited when a new namespace is
> > created. The mode of the current namespace can be queried by reading
> > /proc/sys/net/vsock/ns_mode. The mode can not change after the namespace
> > has been created.
> > 
> > Modes are per-netns. This allows a system to configure namespaces
> > independently (some may share CIDs, others are completely isolated).
> > This also supports future possible mixed use cases, where there may be
> > namespaces in global mode spinning up VMs while there are mixed mode
> > namespaces that provide services to the VMs, but are not allowed to
> > allocate from the global CID pool (this mode is not implemented in this
> > series).
> > 
> > Additionally, added tests for the new namespace features:
> > 
> > tools/testing/selftests/vsock/vmtest.sh
> > 1..25
> > ok 1 vm_server_host_client
> > ok 2 vm_client_host_server
> > ok 3 vm_loopback
> > ok 4 ns_host_vsock_ns_mode_ok
> > ok 5 ns_host_vsock_child_ns_mode_ok
> > ok 6 ns_global_same_cid_fails
> > ok 7 ns_local_same_cid_ok
> > ok 8 ns_global_local_same_cid_ok
> > ok 9 ns_local_global_same_cid_ok
> > ok 10 ns_diff_global_host_connect_to_global_vm_ok
> > ok 11 ns_diff_global_host_connect_to_local_vm_fails
> > ok 12 ns_diff_global_vm_connect_to_global_host_ok
> > ok 13 ns_diff_global_vm_connect_to_local_host_fails
> > ok 14 ns_diff_local_host_connect_to_local_vm_fails
> > ok 15 ns_diff_local_vm_connect_to_local_host_fails
> > ok 16 ns_diff_global_to_local_loopback_local_fails
> > ok 17 ns_diff_local_to_global_loopback_fails
> > ok 18 ns_diff_local_to_local_loopback_fails
> > ok 19 ns_diff_global_to_global_loopback_ok
> > ok 20 ns_same_local_loopback_ok
> > ok 21 ns_same_local_host_connect_to_local_vm_ok
> > ok 22 ns_same_local_vm_connect_to_local_host_ok
> > ok 23 ns_delete_vm_ok
> > ok 24 ns_delete_host_ok
> > ok 25 ns_delete_both_ok
> > SUMMARY: PASS=25 SKIP=0 FAIL=0
> > 
> > Thanks again for everyone's help and reviews!
> 
> Thank you for your hard work and patience!
> 
> I think we've come up with an excellent solution that's also not too
> invasive.

Thanks, and I appreciate all of the work you and other maintainers put
into this as well! I think we honed in on a great solution too.
> 
> All the patches have my R-b, I've double-checked and tested this v16.
> Everything seems to be working fine (famous last words xD).
> 
> So this series is good to go IMO!
> 
> Next step should be to update the vsock(7) namespace.

Sounds good, I'll follow up with that and CC you + other reviewers that
participated here.

Thanks again,
Bobby

Re: [PATCH net-next v16 00/12] vsock: add namespace support to vhost-vsock and loopback

[Michael S. Tsirkin]

On Wed, Jan 21, 2026 at 02:11:40PM -0800, Bobby Eshleman wrote:
> This series adds namespace support to vhost-vsock and loopback. It does
> not add namespaces to any of the other guest transports (virtio-vsock,
> hyperv, or vmci).
> 
> The current revision supports two modes: local and global. Local
> mode is complete isolation of namespaces, while global mode is complete
> sharing between namespaces of CIDs (the original behavior).
> 
> The mode is set using the parent namespace's
> /proc/sys/net/vsock/child_ns_mode and inherited when a new namespace is
> created. The mode of the current namespace can be queried by reading
> /proc/sys/net/vsock/ns_mode. The mode can not change after the namespace
> has been created.
> 
> Modes are per-netns. This allows a system to configure namespaces
> independently (some may share CIDs, others are completely isolated).
> This also supports future possible mixed use cases, where there may be
> namespaces in global mode spinning up VMs while there are mixed mode
> namespaces that provide services to the VMs, but are not allowed to
> allocate from the global CID pool (this mode is not implemented in this
> series).
> 
> Additionally, added tests for the new namespace features:
> 
> tools/testing/selftests/vsock/vmtest.sh
> 1..25
> ok 1 vm_server_host_client
> ok 2 vm_client_host_server
> ok 3 vm_loopback
> ok 4 ns_host_vsock_ns_mode_ok
> ok 5 ns_host_vsock_child_ns_mode_ok
> ok 6 ns_global_same_cid_fails
> ok 7 ns_local_same_cid_ok
> ok 8 ns_global_local_same_cid_ok
> ok 9 ns_local_global_same_cid_ok
> ok 10 ns_diff_global_host_connect_to_global_vm_ok
> ok 11 ns_diff_global_host_connect_to_local_vm_fails
> ok 12 ns_diff_global_vm_connect_to_global_host_ok
> ok 13 ns_diff_global_vm_connect_to_local_host_fails
> ok 14 ns_diff_local_host_connect_to_local_vm_fails
> ok 15 ns_diff_local_vm_connect_to_local_host_fails
> ok 16 ns_diff_global_to_local_loopback_local_fails
> ok 17 ns_diff_local_to_global_loopback_fails
> ok 18 ns_diff_local_to_local_loopback_fails
> ok 19 ns_diff_global_to_global_loopback_ok
> ok 20 ns_same_local_loopback_ok
> ok 21 ns_same_local_host_connect_to_local_vm_ok
> ok 22 ns_same_local_vm_connect_to_local_host_ok
> ok 23 ns_delete_vm_ok
> ok 24 ns_delete_host_ok
> ok 25 ns_delete_both_ok
> SUMMARY: PASS=25 SKIP=0 FAIL=0
> 
> Thanks again for everyone's help and reviews!
> 
> Suggested-by: Sargun Dhillon <sargun@sargun.me>
> Signed-off-by: Bobby Eshleman <bobbyeshleman@gmail.com>


Acked-by: Michael S. Tsirkin <mst@redhat.com>

> 
> Changes in v16:
> - updated comments/docs/commit msg (vsock_find_* funcs, init net
>   mode, why change random port alloc)
> - removed init ns mode cmdline
> - fixed the missing ${ns} arg for vm_ssh in vmtest.sh
> - Link to v15: https://lore.kernel.org/r/20260116-vsock-vmtest-v15-0-bbfd1a668548@meta.com
> 
> Changes in v15:
> - see per-patch change notes in 'vsock: add netns to vsock core'
> - Link to v14: https://lore.kernel.org/r/20260112-vsock-vmtest-v14-0-a5c332db3e2b@meta.com
> 
> Changes in v14:
> - squashed 'vsock: add per-net vsock NS mode state' into 'vsock: add
>   netns to vsock core' (MST)
> - remove RFC tag
> - fixed base-commit (still had b4 configured to depend on old vmtest.sh
>   series)
> - Link to v13: https://lore.kernel.org/all/20251223-vsock-vmtest-v13-0-9d6db8e7c80b@meta.com/
> 
> Changes in v13:
> - add support for immutable sysfs ns_mode and inheritance from sysfs child_ns_mode
> - remove passing around of net_mode, can be accessed now via
>   vsock_net_mode(net) since it is immutable
> - update tests for new uAPI
> - add one patch to extend the kselftest timeout (it was starting to
>   fail with the new tests added)
> - Link to v12: https://lore.kernel.org/r/20251126-vsock-vmtest-v12-0-257ee21cd5de@meta.com
> 
> Changes in v12:
> - add ns mode checking to _allow() callbacks to reject local mode for
>   incompatible transports (Stefano)
> - flip vhost/loopback to return true for stream_allow() and
>   seqpacket_allow() in "vsock: add netns support to virtio transports"
>   (Stefano)
> - add VMADDR_CID_ANY + local mode documentation in af_vsock.c (Stefano)
> - change "selftests/vsock: add tests for host <-> vm connectivity with
>   namespaces" to skip test 29 in vsock_test for namespace local
>   vsock_test calls in a host local-mode namespace. There is a
>   false-positive edge case for that test encountered with the
>   ->stream_allow() approach. More details in that patch.
> - updated cover letter with new test output
> - Link to v11: https://lore.kernel.org/r/20251120-vsock-vmtest-v11-0-55cbc80249a7@meta.com
> 
> Changes in v11:
> - vmtest: add a patch to use ss in wait_for_listener functions and
>   support vsock, tcp, and unix. Change all patches to use the new
>   functions.
> - vmtest: add a patch to re-use vm dmesg / warn counting functions
> - Link to v10: https://lore.kernel.org/r/20251117-vsock-vmtest-v10-0-df08f165bf3e@meta.com
> 
> Changes in v10:
> - Combine virtio common patches into one (Stefano)
> - Resolve vsock_loopback virtio_transport_reset_no_sock() issue
>   with info->vsk setting. This eliminates the need for skb->cb,
>   so remove skb->cb patches.
> - many line width 80 fixes
> - Link to v9: https://lore.kernel.org/all/20251111-vsock-vmtest-v9-0-852787a37bed@meta.com
> 
> Changes in v9:
> - reorder loopback patch after patch for virtio transport common code
> - remove module ordering tests patch because loopback no longer depends
>   on pernet ops
> - major simplifications in vsock_loopback
> - added a new patch for blocking local mode for guests, added test case
>   to check
> - add net ref tracking to vsock_loopback patch
> - Link to v8: https://lore.kernel.org/r/20251023-vsock-vmtest-v8-0-dea984d02bb0@meta.com
> 
> Changes in v8:
> - Break generic cleanup/refactoring patches into standalone series,
>   remove those from this series
> - Link to dependency: https://lore.kernel.org/all/20251022-vsock-selftests-fixes-and-improvements-v1-0-edeb179d6463@meta.com/
> - Link to v7: https://lore.kernel.org/r/20251021-vsock-vmtest-v7-0-0661b7b6f081@meta.com
> 
> Changes in v7:
> - fix hv_sock build
> - break out vmtest patches into distinct, more well-scoped patches
> - change `orig_net_mode` to `net_mode`
> - many fixes and style changes in per-patch change sets (see individual
>   patches for specific changes)
> - optimize `virtio_vsock_skb_cb` layout
> - update commit messages with more useful descriptions
> - vsock_loopback: use orig_net_mode instead of current net mode
> - add tests for edge cases (ns deletion, mode changing, loopback module
>   load ordering)
> - Link to v6: https://lore.kernel.org/r/20250916-vsock-vmtest-v6-0-064d2eb0c89d@meta.com
> 
> Changes in v6:
> - define behavior when mode changes to local while socket/VM is alive
> - af_vsock: clarify description of CID behavior
> - af_vsock: use stronger langauge around CID rules (dont use "may")
> - af_vsock: improve naming of buf/buffer
> - af_vsock: improve string length checking on proc writes
> - vsock_loopback: add space in struct to clarify lock protection
> - vsock_loopback: do proper cleanup/unregister on vsock_loopback_exit()
> - vsock_loopback: use virtio_vsock_skb_net() instead of sock_net()
> - vsock_loopback: set loopback to NULL after kfree()
> - vsock_loopback: use pernet_operations and remove callback mechanism
> - vsock_loopback: add macros for "global" and "local"
> - vsock_loopback: fix length checking
> - vmtest.sh: check for namespace support in vmtest.sh
> - Link to v5: https://lore.kernel.org/r/20250827-vsock-vmtest-v5-0-0ba580bede5b@meta.com
> 
> Changes in v5:
> - /proc/net/vsock_ns_mode -> /proc/sys/net/vsock/ns_mode
> - vsock_global_net -> vsock_global_dummy_net
> - fix netns lookup in vhost_vsock to respect pid namespaces
> - add callbacks for vsock_loopback to avoid circular dependency
> - vmtest.sh loads vsock_loopback module
> - remove vsock_net_mode_can_set()
> - change vsock_net_write_mode() to return true/false based on success
> - make vsock_net_mode enum instead of u8
> - Link to v4: https://lore.kernel.org/r/20250805-vsock-vmtest-v4-0-059ec51ab111@meta.com
> 
> Changes in v4:
> - removed RFC tag
> - implemented loopback support
> - renamed new tests to better reflect behavior
> - completed suite of tests with permutations of ns modes and vsock_test
>   as guest/host
> - simplified socat bridging with unix socket instead of tcp + veth
> - only use vsock_test for success case, socat for failure case (context
>   in commit message)
> - lots of cleanup
> 
> Changes in v3:
> - add notion of "modes"
> - add procfs /proc/net/vsock_ns_mode
> - local and global modes only
> - no /dev/vhost-vsock-netns
> - vmtest.sh already merged, so new patch just adds new tests for NS
> - Link to v2:
>   https://lore.kernel.org/kvm/20250312-vsock-netns-v2-0-84bffa1aa97a@gmail.com
> 
> Changes in v2:
> - only support vhost-vsock namespaces
> - all g2h namespaces retain old behavior, only common API changes
>   impacted by vhost-vsock changes
> - add /dev/vhost-vsock-netns for "opt-in"
> - leave /dev/vhost-vsock to old behavior
> - removed netns module param
> - Link to v1:
>   https://lore.kernel.org/r/20200116172428.311437-1-sgarzare@redhat.com
> 
> Changes in v1:
> - added 'netns' module param to vsock.ko to enable the
>   network namespace support (disabled by default)
> - added 'vsock_net_eq()' to check the "net" assigned to a socket
>   only when 'netns' support is enabled
> - Link to RFC: https://patchwork.ozlabs.org/cover/1202235/
> 
> ---
> Bobby Eshleman (12):
>       vsock: add netns to vsock core
>       virtio: set skb owner of virtio_transport_reset_no_sock() reply
>       vsock: add netns support to virtio transports
>       selftests/vsock: increase timeout to 1200
>       selftests/vsock: add namespace helpers to vmtest.sh
>       selftests/vsock: prepare vm management helpers for namespaces
>       selftests/vsock: add vm_dmesg_{warn,oops}_count() helpers
>       selftests/vsock: use ss to wait for listeners instead of /proc/net
>       selftests/vsock: add tests for proc sys vsock ns_mode
>       selftests/vsock: add namespace tests for CID collisions
>       selftests/vsock: add tests for host <-> vm connectivity with namespaces
>       selftests/vsock: add tests for namespace deletion
> 
>  MAINTAINERS                             |    1 +
>  drivers/vhost/vsock.c                   |   44 +-
>  include/linux/virtio_vsock.h            |    9 +-
>  include/net/af_vsock.h                  |   61 +-
>  include/net/net_namespace.h             |    4 +
>  include/net/netns/vsock.h               |   21 +
>  net/vmw_vsock/af_vsock.c                |  335 +++++++++-
>  net/vmw_vsock/hyperv_transport.c        |    7 +-
>  net/vmw_vsock/virtio_transport.c        |   22 +-
>  net/vmw_vsock/virtio_transport_common.c |   62 +-
>  net/vmw_vsock/vmci_transport.c          |   26 +-
>  net/vmw_vsock/vsock_loopback.c          |   22 +-
>  tools/testing/selftests/vsock/settings  |    2 +-
>  tools/testing/selftests/vsock/vmtest.sh | 1055 +++++++++++++++++++++++++++++--
>  14 files changed, 1531 insertions(+), 140 deletions(-)
> ---
> base-commit: d8f87aa5fa0a4276491fa8ef436cd22605a3f9ba
> change-id: 20250325-vsock-vmtest-b3a21d2102c2
> 
> Best regards,
> -- 
> Bobby Eshleman <bobbyeshleman@meta.com>

Re: [PATCH net-next v16 00/12] vsock: add namespace support to vhost-vsock and loopback

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Paolo Abeni <pabeni@redhat.com>:

On Wed, 21 Jan 2026 14:11:40 -0800 you wrote:
> This series adds namespace support to vhost-vsock and loopback. It does
> not add namespaces to any of the other guest transports (virtio-vsock,
> hyperv, or vmci).
> 
> The current revision supports two modes: local and global. Local
> mode is complete isolation of namespaces, while global mode is complete
> sharing between namespaces of CIDs (the original behavior).
> 
> [...]

Here is the summary with links:
  - [net-next,v16,01/12] vsock: add netns to vsock core
    https://git.kernel.org/netdev/net-next/c/eafb64f40ca4
  - [net-next,v16,02/12] virtio: set skb owner of virtio_transport_reset_no_sock() reply
    https://git.kernel.org/netdev/net-next/c/a6ae12a599e0
  - [net-next,v16,03/12] vsock: add netns support to virtio transports
    https://git.kernel.org/netdev/net-next/c/a69686327e42
  - [net-next,v16,04/12] selftests/vsock: increase timeout to 1200
    https://git.kernel.org/netdev/net-next/c/873e7de9f9a3
  - [net-next,v16,05/12] selftests/vsock: add namespace helpers to vmtest.sh
    https://git.kernel.org/netdev/net-next/c/423ec6383edb
  - [net-next,v16,06/12] selftests/vsock: prepare vm management helpers for namespaces
    https://git.kernel.org/netdev/net-next/c/fd1b41725d58
  - [net-next,v16,07/12] selftests/vsock: add vm_dmesg_{warn,oops}_count() helpers
    https://git.kernel.org/netdev/net-next/c/4e870ac81df7
  - [net-next,v16,08/12] selftests/vsock: use ss to wait for listeners instead of /proc/net
    https://git.kernel.org/netdev/net-next/c/7418f3bb3aa2
  - [net-next,v16,09/12] selftests/vsock: add tests for proc sys vsock ns_mode
    https://git.kernel.org/netdev/net-next/c/06cf7895abf9
  - [net-next,v16,10/12] selftests/vsock: add namespace tests for CID collisions
    https://git.kernel.org/netdev/net-next/c/605caec5adc2
  - [net-next,v16,11/12] selftests/vsock: add tests for host <-> vm connectivity with namespaces
    https://git.kernel.org/netdev/net-next/c/0424ee7c3a17
  - [net-next,v16,12/12] selftests/vsock: add tests for namespace deletion
    https://git.kernel.org/netdev/net-next/c/b3b7b33264c6

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: [PATCH net-next v16 01/12] vsock: add netns to vsock core

[Stefano Garzarella]

Hi,

On Wed, Jan 21, 2026 at 02:11:41PM -0800, Bobby Eshleman wrote:
>From: Bobby Eshleman <bobbyeshleman@meta.com>
>
>Add netns logic to vsock core. Additionally, modify transport hook
>prototypes to be used by later transport-specific patches (e.g.,
>*_seqpacket_allow()).
>
>Namespaces are supported primarily by changing socket lookup functions
>(e.g., vsock_find_connected_socket()) to take into account the socket
>namespace and the namespace mode before considering a candidate socket a
>"match".
>
>This patch also introduces the sysctl /proc/sys/net/vsock/ns_mode to
>report the mode and /proc/sys/net/vsock/child_ns_mode to set the mode
>for new namespaces.

talking about this new feature with Daan (in CC) we were discussing a 
possible change to `child_ns_mode`.

Currently, if two or more administrator processes in the same namespace 
set `child_ns_mode`, they compete. Obviously, after unshare()/clone(), 
the process can always access `ns_mode` to check if everything went well 
and eventually retry.

Daan suggested a more conservative approach, allowing `child_ns_mode` to 
be written only once (a bit like we did in the old version when the 
child could change the mode only once). This way, most users who want 
isolation write `local` in `child_ns_mode` at startup in the init_ns. At 
that point the user  and can be sure that no other process (including 
administrators, e.g., container managers) can change it, so all new 
namespaces will have `local` mode.

I think we should support this option in some way, because it seems to 
simplify the user space in most common cases (ensure isolation). I see 
few options for doing this:

1. Change the behavior of `child_ns_mode` to be written only once, but 
this would limit other possible use cases where `child_ns_mode` can be 
changed more than once (I don't know if Bobby had any in mind).

2. Add a new sysctl `child_ns_mode_lockin` (or something similar), which 
can only be written once with a mode (local or global). A write on this 
will also locks `child_ns_mode`, of course.

3. Add a new `local-locked` mode, reusing the same sysctl.


If we go for 1, maybe we can do it in 7.0, or not?

2 and 3, on the other hand, may have to wait until the next release.

What do you think? Any comments?

Thanks,
Stefano

Re: [PATCH net-next v16 01/12] vsock: add netns to vsock core

[Jakub Kicinski]

On Tue, 17 Feb 2026 16:08:33 +0100 Stefano Garzarella wrote:
> If we go for 1, maybe we can do it in 7.0, or not?

Just my preference but changing the behavior ASAP in 7.0 seems better,
but the code must be ready very soon for that to happen.