or

 $ make -C tools/testing/selftests TARGETS=vsock run_tests

Example runs:

$ ./tools/testing/selftests/vsock/vmtest.sh
TAP version 13
1..3
not ok 0 vm_server_host_client # exit=1
ok 1 vm_client_host_server
ok 2 vm_loopback
1..3

$ ./tools/testing/selftests/vsock/vmtest.sh vm_loopback
TAP version 13
1..1
ok 0 vm_loopback
1..1

Future work can include vsock_diag_test.

The tap output style copies mm's run_vmtests.sh.

Because vsock requires a VM to test anything other than loopback, this
patch adds vmtest.sh as a kselftest itself. This is different than other
systems that have a "vmtest.sh", where it is used as a utility script to
spin up a VM to run the selftests as a guest (but isn't hooked into
kselftest).

Testing in NIPA is still WIP.

Signed-off-by: Bobby Eshleman <redacted>
---
Changes in v5:
- make log file a tmpfile (Paolo)
- make sure both default and user defined QEMU gets handled by the dependency check (Paolo)
- increased VM boot up timeout from 1m to 3m for slow hosts (Paolo)
- rename vm_setup -> vm_start (Paolo)
- derive wait_for_listener from selftests/net/net_helper.sh to removes ss usage
- Remove unused 'unset IFS' line (Paolo)
- leave space after variable declarations (Paolo)
- make QEMU_PIDFILE a tmp file (Paolo)
- make everything readonly that is only read (Paolo)
- source ktap_helpers.sh for KSFT_PASS and friends (Paolo)
- don't check for timeout util (Paolo)
- add missing usage string for -q qemu arg
- add tap prefix to SUMMARY line since it isn't part of TAP protocol
- exit with the correct status code based on failure/pass counts
- Link to v4: 
https://lore.kernel.org/r/20250507-vsock-vmtest-v4-1-6e2a97262cd6@gmail.com (local)

Changes in v4:
- do not use special tab delimiter for help string parsing (Stefano + Paolo)
- fix paths for when installing kselftest and running out-of-tree (Paolo)
- change vng to using running kernel instead of compiled kernel (Paolo)
- use multi-line string for QEMU_OPTS (Stefano)
- change timeout to 300s (Paolo)
- skip if tools are not found and use kselftests status codes (Paolo)
- remove build from vmtest.sh (Paolo)
- change 2222 -> SSH_HOST_PORT (Stefano)
- add tap-format output
- add vmtest.log to gitignore
- check for vsock_test binary and remind user to build it if missing
- create a proper build in makefile
- style fixes
- add ssh, timeout, and pkill to dependency check, just in case
- fix numerical comparison in conditionals
- check qemu pidfile exists before proceeding (avoid wasting time waiting for ssh)
- fix tracking of pass/fail bug
- fix stderr redirection bug
- Link to v3: https://lore.kernel.org/r/20250428-vsock-vmtest-v3-1-181af6163f3e@gmail.com (local)

Changes in v3:
- use common conditional syntax for checking variables
- use return value instead of global rc
- fix typo TEST_HOST_LISTENER_PORT -> TEST_HOST_PORT_LISTENER
- use SIGTERM instead of SIGKILL on cleanup
- use peer-cid=1 for loopback
- change sleep delay times into globals
- fix test_vm_loopback logging
- add test selection in arguments
- make QEMU an argument
- check that vng binary is on path
- use QEMU variable
- change <tab><backslash> to <space><backslash>
- fix hardcoded file paths
- add comment in commit msg about script that vmtest.sh was based off of
- Add tools/testing/selftest/vsock/Makefile for kselftest
- Link to v2: https://lore.kernel.org/r/20250417-vsock-vmtest-v2-1-3901a27331e8@gmail.com (local)

Changes in v2:
- add kernel oops and warnings checker
- change testname variable to use FUNCNAME
- fix spacing in test_vm_server_host_client
- add -s skip build option to vmtest.sh
- add test_vm_loopback
- pass port to vm_wait_for_listener
- fix indentation in vmtest.sh
- add vmci and hyperv to config
- changed whitespace from tabs to spaces in help string
- Link to v1: https://lore.kernel.org/r/20250410-vsock-vmtest-v1-1-f35a81dab98c@gmail.com (local)
---
MAINTAINERS                              |   1 +
tools/testing/selftests/vsock/.gitignore |   2 +
tools/testing/selftests/vsock/Makefile   |  16 ++
tools/testing/selftests/vsock/config     | 114 ++++++++
tools/testing/selftests/vsock/settings   |   1 +
tools/testing/selftests/vsock/vmtest.sh  | 441 +++++++++++++++++++++++++++++++
6 files changed, 575 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 657a67f9031ef7798c19ac63e6383d4cb18a9e1f..3fbdd7bbfce7196a3cc7db70203317c6bd0e51fd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS

@@ -25751,6 +25751,7 @@ F:	include/uapi/linux/vm_sockets.h

F:	include/uapi/linux/vm_sockets_diag.h
F:	include/uapi/linux/vsockmon.h
F:	net/vmw_vsock/
+F:	tools/testing/selftests/vsock/
F:	tools/testing/vsock/

VMALLOC

diff --git a/tools/testing/selftests/vsock/.gitignore b/tools/testing/selftests/vsock/.gitignore
new file mode 100644
index 0000000000000000000000000000000000000000..9c5bf379480f829a14713d5f5dc7d525bc272e84
--- /dev/null
+++ b/tools/testing/selftests/vsock/.gitignore

@@ -0,0 +1,2 @@
+vmtest.log
+vsock_test

diff --git a/tools/testing/selftests/vsock/Makefile b/tools/testing/selftests/vsock/Makefile
new file mode 100644
index 0000000000000000000000000000000000000000..7ab4970e5e8a019be33f96a36f95c00573d7bfcf
--- /dev/null
+++ b/tools/testing/selftests/vsock/Makefile

@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0
+
+CURDIR := $(abspath .)
+TOOLSDIR := $(abspath ../../..)
+
+$(OUTPUT)/vsock_test: $(TOOLSDIR)/testing/vsock/vsock_test
+	install -m 755 $< $@
+
+$(TOOLSDIR)/testing/vsock/vsock_test:
+	$(MAKE) -C $(TOOLSDIR)/testing/vsock vsock_test

+
+TEST_PROGS += vmtest.sh
+TEST_GEN_FILES := vsock_test
+
+include ../lib.mk
+

diff --git a/tools/testing/selftests/vsock/config b/tools/testing/selftests/vsock/config
new file mode 100644
index 0000000000000000000000000000000000000000..3bffaaf98fff92dc0e3bc1286afa3d8d5d52f4c7
--- /dev/null
+++ b/tools/testing/selftests/vsock/config

@@ -0,0 +1,114 @@
+CONFIG_BLK_DEV_INITRD=y
+CONFIG_BPF=y
+CONFIG_BPF_SYSCALL=y
+CONFIG_BPF_JIT=y
+CONFIG_HAVE_EBPF_JIT=y
+CONFIG_BPF_EVENTS=y
+CONFIG_FTRACE_SYSCALLS=y
+CONFIG_FUNCTION_TRACER=y
+CONFIG_HAVE_DYNAMIC_FTRACE=y
+CONFIG_DYNAMIC_FTRACE=y
+CONFIG_HAVE_KPROBES=y
+CONFIG_KPROBES=y
+CONFIG_KPROBE_EVENTS=y
+CONFIG_ARCH_SUPPORTS_UPROBES=y
+CONFIG_UPROBES=y
+CONFIG_UPROBE_EVENTS=y
+CONFIG_DEBUG_FS=y
+CONFIG_FW_CFG_SYSFS=y
+CONFIG_FW_CFG_SYSFS_CMDLINE=y
+CONFIG_DRM=y
+CONFIG_DRM_VIRTIO_GPU=y
+CONFIG_DRM_VIRTIO_GPU_KMS=y
+CONFIG_DRM_BOCHS=y
+CONFIG_VIRTIO_IOMMU=y
+CONFIG_SOUND=y
+CONFIG_SND=y
+CONFIG_SND_SEQUENCER=y
+CONFIG_SND_PCI=y
+CONFIG_SND_INTEL8X0=y
+CONFIG_SND_HDA_CODEC_REALTEK=y
+CONFIG_SECURITYFS=y
+CONFIG_CGROUP_BPF=y
+CONFIG_SQUASHFS=y
+CONFIG_SQUASHFS_XZ=y
+CONFIG_SQUASHFS_ZSTD=y
+CONFIG_FUSE_FS=y
+CONFIG_SERIO=y
+CONFIG_PCI=y
+CONFIG_INPUT=y
+CONFIG_INPUT_KEYBOARD=y
+CONFIG_KEYBOARD_ATKBD=y
+CONFIG_SERIAL_8250=y
+CONFIG_SERIAL_8250_CONSOLE=y
+CONFIG_X86_VERBOSE_BOOTUP=y
+CONFIG_VGA_CONSOLE=y
+CONFIG_FB=y
+CONFIG_FB_VESA=y
+CONFIG_FRAMEBUFFER_CONSOLE=y
+CONFIG_RTC_CLASS=y
+CONFIG_RTC_HCTOSYS=y
+CONFIG_RTC_DRV_CMOS=y
+CONFIG_HYPERVISOR_GUEST=y
+CONFIG_PARAVIRT=y
+CONFIG_KVM_GUEST=y
+CONFIG_KVM=y
+CONFIG_KVM_INTEL=y
+CONFIG_KVM_AMD=y
+CONFIG_VSOCKETS=y
+CONFIG_VSOCKETS_DIAG=y
+CONFIG_VSOCKETS_LOOPBACK=y
+CONFIG_VMWARE_VMCI_VSOCKETS=y
+CONFIG_VIRTIO_VSOCKETS=y
+CONFIG_VIRTIO_VSOCKETS_COMMON=y
+CONFIG_HYPERV_VSOCKETS=y
+CONFIG_VMWARE_VMCI=y
+CONFIG_VHOST_VSOCK=y
+CONFIG_HYPERV=y
+CONFIG_UEVENT_HELPER=n
+CONFIG_VIRTIO=y
+CONFIG_VIRTIO_PCI=y
+CONFIG_VIRTIO_MMIO=y
+CONFIG_VIRTIO_BALLOON=y
+CONFIG_NET=y
+CONFIG_NET_CORE=y
+CONFIG_NETDEVICES=y
+CONFIG_NETWORK_FILESYSTEMS=y
+CONFIG_INET=y
+CONFIG_NET_9P=y
+CONFIG_NET_9P_VIRTIO=y
+CONFIG_9P_FS=y
+CONFIG_VIRTIO_NET=y
+CONFIG_CMDLINE_OVERRIDE=n
+CONFIG_BINFMT_SCRIPT=y
+CONFIG_SHMEM=y
+CONFIG_TMPFS=y
+CONFIG_UNIX=y
+CONFIG_MODULE_SIG_FORCE=n
+CONFIG_DEVTMPFS=y
+CONFIG_TTY=y
+CONFIG_VT=y
+CONFIG_UNIX98_PTYS=y
+CONFIG_EARLY_PRINTK=y
+CONFIG_INOTIFY_USER=y
+CONFIG_BLOCK=y
+CONFIG_SCSI_LOWLEVEL=y
+CONFIG_SCSI=y
+CONFIG_SCSI_VIRTIO=y
+CONFIG_BLK_DEV_SD=y
+CONFIG_VIRTIO_CONSOLE=y
+CONFIG_WATCHDOG=y
+CONFIG_WATCHDOG_CORE=y
+CONFIG_I6300ESB_WDT=y
+CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y
+CONFIG_OVERLAY_FS=y
+CONFIG_DAX=y
+CONFIG_DAX_DRIVER=y
+CONFIG_FS_DAX=y
+CONFIG_MEMORY_HOTPLUG=y
+CONFIG_MEMORY_HOTREMOVE=y
+CONFIG_ZONE_DEVICE=y
+CONFIG_FUSE_FS=y
+CONFIG_VIRTIO_FS=y
+CONFIG_VSOCKETS=y
+CONFIG_VIRTIO_VSOCKETS=y

diff --git a/tools/testing/selftests/vsock/settings 

b/tools/testing/selftests/vsock/settings
new file mode 100644
index 0000000000000000000000000000000000000000..694d70710ff08ac9fc91e9ecb5dbdadcf051f019

--- /dev/null
+++ b/tools/testing/selftests/vsock/settings

@@ -0,0 +1 @@
+timeout=300

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
new file mode 100755
index 0000000000000000000000000000000000000000..f5f920e83db6d24793b435b373e75d6051b7a9d5
--- /dev/null
+++ b/tools/testing/selftests/vsock/vmtest.sh

@@ -0,0 +1,441 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) 2025 Meta Platforms, Inc. and affiliates
+#
+# Dependencies:
+#		* virtme-ng
+#		* busybox-static (used by virtme-ng)
+#		* qemu	(used by virtme-ng)
+
+readonly SCRIPT_DIR="$(cd -P -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd -P)"
+
+source ${SCRIPT_DIR}/../kselftest/ktap_helpers.sh
+
+readonly TAP_PREFIX="# "
+readonly VSOCK_TEST=${SCRIPT_DIR}/vsock_test
+
+readonly TEST_GUEST_PORT=51000
+readonly TEST_HOST_PORT=50000
+readonly TEST_HOST_PORT_LISTENER=50001
+readonly SSH_GUEST_PORT=22
+readonly SSH_HOST_PORT=2222
+readonly VSOCK_CID=1234
+readonly WAIT_PERIOD=3
+readonly WAIT_PERIOD_MAX=60
+readonly WAIT_TOTAL=$(( WAIT_PERIOD * WAIT_PERIOD_MAX ))
+readonly QEMU_PIDFILE=$(mktemp /tmp/qemu_vsock_vmtest_XXXX.pid)
+
+# virtme-ng offers a netdev for ssh when using "--ssh", but we also need a
+# control port forwarded for vsock_test.  Because virtme-ng doesn't support
+# adding an additional port to forward to the device created from "--ssh" and
+# virtme-init mistakenly sets identical IPs to the ssh device and additional
+# devices, we instead opt out of using --ssh, add the device manually, and also
+# add the kernel cmdline options that virtme-init uses to setup the interface.
+readonly QEMU_TEST_PORT_FWD="hostfwd=tcp::${TEST_HOST_PORT}-:${TEST_GUEST_PORT}"
+readonly QEMU_SSH_PORT_FWD="hostfwd=tcp::${SSH_HOST_PORT}-:${SSH_GUEST_PORT}"
+readonly QEMU_OPTS="\
+	 -netdev user,id=n0,${QEMU_TEST_PORT_FWD},${QEMU_SSH_PORT_FWD} \
+	 -device virtio-net-pci,netdev=n0 \
+	 -device vhost-vsock-pci,guest-cid=${VSOCK_CID} \
+	 --pidfile ${QEMU_PIDFILE} \
+"
+readonly KERNEL_CMDLINE="virtme.dhcp net.ifnames=0 biosdevname=0 virtme.ssh virtme_ssh_user=$USER"
+readonly LOG=$(mktemp /tmp/vsock_vmtest_XXXX.log)
+readonly TEST_NAMES=(vm_server_host_client vm_client_host_server vm_loopback)
+readonly TEST_DESCS=(
+	"Run vsock_test in server mode on the VM and in client mode on the host."
+	"Run vsock_test in client mode on the VM and in server mode on the host."
+	"Run vsock_test using the loopback transport in the VM."
+)
+
+VERBOSE=0
+
+usage() {
+	local name
+	local desc
+	local i
+
+	echo
+	echo "$0 [OPTIONS] [TEST]..."
+	echo "If no TEST argument is given, all tests will be run."
+	echo
+	echo "Options"
+	echo "  -v: verbose output"
+	echo "  -q: set the path to or name of qemu binary"
+	echo
+	echo "Available tests"
+
+	for ((i = 0; i < ${#TEST_NAMES[@]}; i++)); do
+		name=${TEST_NAMES[${i}]}
+		desc=${TEST_DESCS[${i}]}
+		printf "\t%-35s%-35s\n" "${name}" "${desc}"
+	done
+	echo
+
+	exit 1
+}
+
+die() {
+	echo "$*" >&2
+	exit ${KSFT_FAIL}
+}
+
+vm_ssh() {
+	ssh -q -o UserKnownHostsFile=/dev/null -p ${SSH_HOST_PORT} localhost $*
+	return $?
+}
+
+cleanup() {
+	if [[ -f "${QEMU_PIDFILE}" ]]; then