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 /proc/sys/net/vsock/ns_mode.
Modes are per-netns and write-once. 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).
If a socket or VM is created when a namespace is global but the namespace changes to local, the socket or VM will continue working normally. That is, the socket or VM assumes the mode behavior of the namespace at the time the socket/VM was created. The original mode is captured in vsock_create() and so occurs at the time of socket(2) and accept(2) for sockets and open(2) on /dev/vhost-vsock for VMs. This prevents a socket/VM connection from suddenly breaking due to a namespace mode change. Any new sockets/VMs created after the mode change will adopt the new mode's behavior.
Additionally, added tests for the new namespace features:
tools/testing/selftests/vsock/vmtest.sh 1..29 ok 1 vm_server_host_client ok 2 vm_client_host_server ok 3 vm_loopback ok 4 ns_guest_local_mode_rejected ok 5 ns_host_vsock_ns_mode_ok ok 6 ns_host_vsock_ns_mode_write_once_ok ok 7 ns_global_same_cid_fails ok 8 ns_local_same_cid_ok ok 9 ns_global_local_same_cid_ok ok 10 ns_local_global_same_cid_ok ok 11 ns_diff_global_host_connect_to_global_vm_ok ok 12 ns_diff_global_host_connect_to_local_vm_fails ok 13 ns_diff_global_vm_connect_to_global_host_ok ok 14 ns_diff_global_vm_connect_to_local_host_fails ok 15 ns_diff_local_host_connect_to_local_vm_fails ok 16 ns_diff_local_vm_connect_to_local_host_fails ok 17 ns_diff_global_to_local_loopback_local_fails ok 18 ns_diff_local_to_global_loopback_fails ok 19 ns_diff_local_to_local_loopback_fails ok 20 ns_diff_global_to_global_loopback_ok ok 21 ns_same_local_loopback_ok ok 22 ns_same_local_host_connect_to_local_vm_ok ok 23 ns_same_local_vm_connect_to_local_host_ok ok 24 ns_mode_change_connection_continue_vm_ok ok 25 ns_mode_change_connection_continue_host_ok ok 26 ns_mode_change_connection_continue_both_ok ok 27 ns_delete_vm_ok ok 28 ns_delete_host_ok ok 29 ns_delete_both_ok SUMMARY: PASS=29 SKIP=0 FAIL=0
Dependent on series: https://lore.kernel.org/all/20251108-vsock-selftests-fixes-and-improvements-...
Thanks again for everyone's help and reviews!
Suggested-by: Sargun Dhillon sargun@sargun.me Signed-off-by: Bobby Eshleman bobbyeshleman@gmail.com
To: Stefano Garzarella sgarzare@redhat.com To: Shuah Khan shuah@kernel.org To: David S. Miller davem@davemloft.net To: Eric Dumazet edumazet@google.com To: Jakub Kicinski kuba@kernel.org To: Paolo Abeni pabeni@redhat.com To: Simon Horman horms@kernel.org To: Stefan Hajnoczi stefanha@redhat.com To: Michael S. Tsirkin mst@redhat.com To: Jason Wang jasowang@redhat.com To: Xuan Zhuo xuanzhuo@linux.alibaba.com To: Eugenio Pérez eperezma@redhat.com To: K. Y. Srinivasan kys@microsoft.com To: Haiyang Zhang haiyangz@microsoft.com To: Wei Liu wei.liu@kernel.org To: Dexuan Cui decui@microsoft.com To: Bryan Tan bryan-bt.tan@broadcom.com To: Vishnu Dasa vishnu.dasa@broadcom.com To: Broadcom internal kernel review list bcm-kernel-feedback-list@broadcom.com Cc: virtualization@lists.linux.dev Cc: netdev@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org Cc: linux-hyperv@vger.kernel.org Cc: berrange@redhat.com Cc: Sargun Dhillon sargun@sargun.me
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-... - 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 (14): vsock: a per-net vsock NS mode state vsock: add netns to vsock core vsock/virtio: add netns support to virtio transport and virtio common vsock/virtio: pack struct virtio_vsock_skb_cb vsock: add netns and netns_tracker to vsock skb cb vsock/loopback: add netns support vhost/vsock: add netns support vsock: reject bad VSOCK_NET_MODE_LOCAL configuration for G2H selftests/vsock: add namespace helpers to vmtest.sh selftests/vsock: prepare vm management helpers for namespaces 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 and mode changes
MAINTAINERS | 1 + drivers/vhost/vsock.c | 48 +- include/linux/virtio_vsock.h | 43 +- include/net/af_vsock.h | 57 +- include/net/net_namespace.h | 4 + include/net/netns/vsock.h | 17 + net/vmw_vsock/af_vsock.c | 290 +++++++++- net/vmw_vsock/hyperv_transport.c | 1 + net/vmw_vsock/virtio_transport.c | 14 +- net/vmw_vsock/virtio_transport_common.c | 57 +- net/vmw_vsock/vsock_loopback.c | 48 +- tools/testing/selftests/vsock/vmtest.sh | 931 ++++++++++++++++++++++++++++++-- 12 files changed, 1418 insertions(+), 93 deletions(-) --- base-commit: 962ac5ca99a5c3e7469215bf47572440402dfd59 change-id: 20250325-vsock-vmtest-b3a21d2102c2 prerequisite-message-id: 20251022-vsock-selftests-fixes-and-improvements-v1-0-edeb179d6463@meta.com prerequisite-patch-id: a2eecc3851f2509ed40009a7cab6990c6d7cfff5 prerequisite-patch-id: 501db2100636b9c8fcb3b64b8b1df797ccbede85 prerequisite-patch-id: ba1a2f07398a035bc48ef72edda41888614be449 prerequisite-patch-id: fd5cc5445aca9355ce678e6d2bfa89fab8a57e61 prerequisite-patch-id: 795ab4432ffb0843e22b580374782e7e0d99b909 prerequisite-patch-id: 1499d263dc933e75366c09e045d2125ca39f7ddd prerequisite-patch-id: f92d99bb1d35d99b063f818a19dcda999152d74c prerequisite-patch-id: e3296f38cdba6d903e061cff2bbb3e7615e8e671 prerequisite-patch-id: bc4662b4710d302d4893f58708820fc2a0624325 prerequisite-patch-id: f8991f2e98c2661a706183fde6b35e2b8d9aedcf prerequisite-patch-id: 44bf9ed69353586d284e5ee63d6fffa30439a698 prerequisite-patch-id: d50621bc630eeaf608bbaf260370c8dabf6326df
Best regards,