Re: [PATCH net-next v10 10/11] selftests/vsock: add tests for host <-> vm connectivity with namespaces

On Mon, Nov 17, 2025 at 06:00:33PM -0800, Bobby Eshleman wrote:

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_start() and vm_dmesg_check() to encapsulate checking dmesg for oops and warnings.

Signed-off-by: Bobby Eshleman bobbyeshleman@meta.com

Changes in v10:

• add vm_dmesg_start() and vm_dmesg_check()

Changes in v9:

• consistent variable quoting

---

tools/testing/selftests/vsock/vmtest.sh | 558 +++++++++++++++++++++++++++++++- 1 file changed, 556 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh index a8bf78a5075d..9c12c1bd1edc 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

@@ -52,6 +53,19 @@ 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=( @@ -113,7 +166,7 @@ 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

@@ -232,7 +285,7 @@ check_args() { }

check_deps() {

• for dep in vng ${QEMU} busybox pkill ssh; do

• for dep in vng ${QEMU} busybox pkill ssh socat; do if [[ ! -x $(command -v "${dep}") ]]; then echo -e "skip: dependency ${dep} not found!\n" exit "${KSFT_SKIP}"

@@ -283,6 +336,20 @@ 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 @@ -331,6 +398,14 @@ 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 @@ -444,6 +519,40 @@ 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_dmesg_check() {

• local pidfile=$1
• local ns=$2
• local oops_before=$3
• local warn_before=$4
• local oops_after warn_after
• oops_after=$(vm_ssh "${ns}" -- dmesg 2>/dev/null | grep -c -i 'Oops')
• if [[ "${oops_after}" -gt "${oops_before}" ]]; then

• echo "FAIL: kernel oops detected on vm in ns ${ns}" | log_host
  

• return 1
  

• fi
• warn_after=$(vm_ssh "${ns}" -- dmesg --level=warn 2>/dev/null | grep -c -i 'vsock')
• 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=$2 @@ -568,6 +677,450 @@ test_ns_host_vsock_ns_mode_ok() { return "${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)

Should we remove this file at the end of this test?

• ip netns exec "${ns1}" \

• socat TCP-LISTEN:"${TEST_HOST_PORT}",fork \
  

• 	UNIX-CONNECT:"${unixfile}" &
  

• pids+=($!)
• host_wait_for_listener "${ns1}" "${TEST_HOST_PORT}"
• ip netns exec "${ns0}" socat UNIX-LISTEN:"${unixfile}",fork \

• TCP-CONNECT:localhost:"${TEST_HOST_PORT}" &
  

• pids+=($!)
• vm_vsock_test "${ns0}" "server" 2 "${TEST_GUEST_PORT}"
• vm_wait_for_listener "${ns0}" "${TEST_GUEST_PORT}"
• host_vsock_test "${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}" &

Should we wait for the listener here, like we do for TCP sockets? (also in other place where we use VSOCK-LISTEN)

• 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+=($!)
• ip netns exec "${ns1}" \

• socat UNIX-LISTEN:"${unixfile}" TCP-CONNECT:127.0.0.1:"${port}" &
  

• pids+=($!)
• 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 &> "${outfile}" &
• pid=$!
• 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}" &
• 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 &> "${outfile}" &
• pid=$!
• 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 > "${outfile}" 2>/dev/null &
• pid=$!
• 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 "${TEST_GUEST_PORT}"
• host_vsock_test "${ns}" "127.0.0.1" "${VSOCK_CID}" "${TEST_HOST_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}"

+}

+test_ns_same_local_vm_connect_to_local_host_ok() {

I don't understand the difference between this test and the previous one (test_ns_same_local_host_connect_to_local_vm_ok).

Maybe there is a copy/paste issue and we need to invert server/client.

Can you check?

• 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 "${TEST_GUEST_PORT}"
• host_vsock_test "${ns}" "127.0.0.1" "${VSOCK_CID}" "${TEST_HOST_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=$2 @@ -861,6 +1414,7 @@ fi check_args "${ARGS[@]}" check_deps check_vng +check_socat handle_build

echo "1..${#ARGS[@]}"

-- 2.47.3