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 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..22 ok 1 vm_server_host_client ok 2 vm_client_host_server ok 3 vm_loopback ok 4 host_vsock_ns_mode_ok ok 5 host_vsock_ns_mode_write_once_ok ok 6 global_same_cid_fails ok 7 local_same_cid_ok ok 8 global_local_same_cid_ok ok 9 local_global_same_cid_ok ok 10 diff_ns_global_host_connect_to_global_vm_ok ok 11 diff_ns_global_host_connect_to_local_vm_fails ok 12 diff_ns_global_vm_connect_to_global_host_ok ok 13 diff_ns_global_vm_connect_to_local_host_fails ok 14 diff_ns_local_host_connect_to_local_vm_fails ok 15 diff_ns_local_vm_connect_to_local_host_fails ok 16 diff_ns_global_to_local_loopback_local_fails ok 17 diff_ns_local_to_global_loopback_fails ok 18 diff_ns_local_to_local_loopback_fails ok 19 diff_ns_global_to_global_loopback_ok ok 20 same_ns_local_loopback_ok ok 21 same_ns_local_host_connect_to_local_vm_ok ok 22 same_ns_local_vm_connect_to_local_host_ok SUMMARY: PASS=22 SKIP=0 FAIL=0 Log: /tmp/vsock_vmtest_OQC4.log Thanks again for everyone's help and reviews! Signed-off-by: Bobby Eshleman <bobbyeshle...@gmail.com> To: Stefano Garzarella <sgarz...@redhat.com> To: Shuah Khan <sh...@kernel.org> To: David S. Miller <da...@davemloft.net> To: Eric Dumazet <eduma...@google.com> To: Jakub Kicinski <k...@kernel.org> To: Paolo Abeni <pab...@redhat.com> To: Simon Horman <ho...@kernel.org> To: Stefan Hajnoczi <stefa...@redhat.com> To: Michael S. Tsirkin <m...@redhat.com> To: Jason Wang <jasow...@redhat.com> To: Xuan Zhuo <xuanz...@linux.alibaba.com> To: Eugenio Pérez <epere...@redhat.com> To: K. Y. Srinivasan <k...@microsoft.com> To: Haiyang Zhang <haiya...@microsoft.com> To: Wei Liu <wei....@kernel.org> To: Dexuan Cui <de...@microsoft.com> To: Bryan Tan <bryan-bt....@broadcom.com> To: Vishnu Dasa <vishnu.d...@broadcom.com> To: Broadcom internal kernel review list <bcm-kernel-feedback-l...@broadcom.com> Cc: virtualizat...@lists.linux.dev Cc: net...@vger.kernel.org Cc: linux-kselft...@vger.kernel.org Cc: linux-ker...@vger.kernel.org Cc: k...@vger.kernel.org Cc: linux-hyperv@vger.kernel.org Cc: berra...@redhat.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-v5-0-0ba580bed...@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-v4-0-059ec51ab...@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-v2-0-84bffa1aa...@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-sgarz...@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 (9): vsock: a per-net vsock NS mode state vsock: add net to vsock skb cb vsock: add netns to vsock core vsock/loopback: add netns support vsock/virtio: add netns to virtio transport common vhost/vsock: add netns support selftests/vsock: improve logging in vmtest.sh selftests/vsock: invoke vsock_test through helpers selftests/vsock: add namespace tests MAINTAINERS | 1 + drivers/vhost/vsock.c | 78 ++- include/linux/virtio_vsock.h | 24 + include/net/af_vsock.h | 71 +- include/net/net_namespace.h | 4 + include/net/netns/vsock.h | 26 + net/vmw_vsock/af_vsock.c | 219 +++++- net/vmw_vsock/hyperv_transport.c | 2 +- net/vmw_vsock/virtio_transport.c | 6 +- net/vmw_vsock/virtio_transport_common.c | 18 +- net/vmw_vsock/vmci_transport.c | 6 +- net/vmw_vsock/vsock_loopback.c | 102 ++- tools/testing/selftests/vsock/vmtest.sh | 1133 +++++++++++++++++++++++++++---- 13 files changed, 1501 insertions(+), 189 deletions(-) --- base-commit: 949ddfb774fe527cebfa3f769804344940f7ed2e change-id: 20250325-vsock-vmtest-b3a21d2102c2 Best regards, -- Bobby Eshleman <bobbyeshle...@meta.com>
