On Thu, Nov 20, 2025 at 09:44:43PM -0800, Bobby Eshleman wrote:
From: Bobby Eshleman <[email protected]>
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.
Signed-off-by: Bobby Eshleman <[email protected]>
---
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(+)
Reviewed-by: Stefano Garzarella <[email protected]>
diff --git a/tools/testing/selftests/vsock/vmtest.sh
b/tools/testing/selftests/vsock/vmtest.sh
index 2e077e8a1777..f84da1e8ad14 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -51,6 +51,10 @@ readonly TEST_NAMES=(
ns_host_vsock_ns_mode_ok
ns_host_vsock_ns_mode_write_once_ok
ns_vm_local_mode_rejected
+ 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
@@ -70,6 +74,18 @@ readonly TEST_DESCS=(
# ns_vm_local_mode_rejected
"Test that guest VM with G2H transport cannot set namespace mode to
'local'"
+
+ # 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=(
@@ -581,6 +597,68 @@ 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 "${KSFT_FAIL}"
+}
+
test_ns_host_vsock_ns_mode_write_once_ok() {
for mode in "${NS_MODES[@]}"; do
local ns="${mode}0"
--
2.47.3
