On Fri, May 02, 2025 at 12:22:46PM +0200, Paolo Abeni wrote:

On 4/29/25 1:48 AM, Bobby Eshleman wrote:

quoted

This commit introduces a new vmtest.sh runner for vsock.

It uses virtme-ng/qemu to run tests in a VM. The tests validate G2H,
H2G, and loopback. The testing tools from tools/testing/vsock/ are
reused. Currently, only vsock_test is used.

VMCI and hyperv support is automatically built, though not used.

Only tested on x86.

To run:

  $ tools/testing/selftests/vsock/vmtest.sh

or

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

Results:
	# linux/tools/testing/selftests/vsock/vmtest.log
	setup:  Building kernel and tests
	setup:  Booting up VM
	setup:  VM booted up
	test:vm_server_host_client:guest:       Control socket listening on 0.0.0.0:51000
	test:vm_server_host_client:guest:       Control socket connection accepted...
	[...]
	test:vm_loopback:guest: 30 - SOCK_STREAM retry failed connect()...ok
	test:vm_loopback:guest: 31 - SOCK_STREAM SO_LINGER null-ptr-deref...ok
	test:vm_loopback:guest: 31 - SOCK_STREAM SO_LINGER null-ptr-deref...ok

Future work can include vsock_diag_test.

vmtest.sh is loosely based off of tools/testing/selftests/net/pmtu.sh,
which was picked out of the bag of tests I knew to work with NIPA.

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). This aspect is worth review, as I'm not aware of all of the
enviroments where this would run.

I think this approach is interesting, but I think it will need some
additional more work, see below...

[...]

quoted

diff --git a/tools/testing/selftests/vsock/settings b/tools/testing/selftests/vsock/settings
new file mode 100644
index 0000000000000000000000000000000000000000..e7b9417537fbc4626153b72e8f295ab4594c844b
--- /dev/null
+++ b/tools/testing/selftests/vsock/settings

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

We need a reasonable, bounded runtime for nipa integration.

quoted

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
new file mode 100755
index 0000000000000000000000000000000000000000..d70b9446e531d6d20beb24ddeda2cf0a9f7e9a39
--- /dev/null
+++ b/tools/testing/selftests/vsock/vmtest.sh

@@ -0,0 +1,354 @@
+#!/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)

You should probably check for such tools presence and bail out with skip
otherwise.

quoted

+
+SCRIPT_DIR="$(cd -P -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd -P)"
+KERNEL_CHECKOUT=$(realpath ${SCRIPT_DIR}/../../../..)

This is not going to work if/when the self-tests are installed in their
own directory via `make install` in the tools/testing/selftests/
directory, and that use case is supposed to work.

At very least you should check for the expected layout and skip otherwise.

quoted

+QEMU=$(command -v qemu-system-$(uname -m))
+VERBOSE=0
+SKIP_BUILD=0
+VSOCK_TEST=${KERNEL_CHECKOUT}/tools/testing/vsock/vsock_test
+
+TEST_GUEST_PORT=51000
+TEST_HOST_PORT=50000
+TEST_HOST_PORT_LISTENER=50001
+SSH_GUEST_PORT=22
+SSH_HOST_PORT=2222
+VSOCK_CID=1234
+WAIT_PERIOD=3
+WAIT_PERIOD_MAX=20
+
+QEMU_PIDFILE=/tmp/qemu.pid
+
+# virtme-ng offers a netdev for ssh when using "--ssh", but we also need a
+# control port forwarded for vsock_test.  Because virtme-ng doesn't support
+# adding an additional port to forward to the device created from "--ssh" and
+# virtme-init mistakenly sets identical IPs to the ssh device and additional
+# devices, we instead opt out of using --ssh, add the device manually, and also
+# add the kernel cmdline options that virtme-init uses to setup the interface.
+QEMU_OPTS=""
+QEMU_OPTS="${QEMU_OPTS} -netdev user,id=n0,hostfwd=tcp::${TEST_HOST_PORT}-:${TEST_GUEST_PORT}"
+QEMU_OPTS="${QEMU_OPTS},hostfwd=tcp::${SSH_HOST_PORT}-:${SSH_GUEST_PORT}"
+QEMU_OPTS="${QEMU_OPTS} -device virtio-net-pci,netdev=n0"
+QEMU_OPTS="${QEMU_OPTS} -device vhost-vsock-pci,guest-cid=${VSOCK_CID}"
+QEMU_OPTS="${QEMU_OPTS} --pidfile ${QEMU_PIDFILE}"
+KERNEL_CMDLINE="virtme.dhcp net.ifnames=0 biosdevname=0 virtme.ssh virtme_ssh_user=$USER"
+
+LOG=${SCRIPT_DIR}/vmtest.log
+
+#		Name				Description
+avail_tests="
+	vm_server_host_client	Run vsock_test in server mode on the VM and in client mode on the host.	
+	vm_client_host_server	Run vsock_test in client mode on the VM and in server mode on the host.	
+	vm_loopback		Run vsock_test using the loopback transport in the VM.	
+"
+
+usage() {
+	echo
+	echo "$0 [OPTIONS] [TEST]..."
+	echo "If no TEST argument is given, all tests will be run."
+	echo
+	echo "Options"
+	echo "  -v: verbose output"
+	echo "  -s: skip build"
+	echo
+	echo "Available tests${avail_tests}"
+	exit 1
+}
+
+die() {
+	echo "$*" >&2
+	exit 1
+}
+
+vm_ssh() {
+	ssh -q -o UserKnownHostsFile=/dev/null -p 2222 localhost $*
+	return $?
+}
+
+cleanup() {
+	if [[ -f "${QEMU_PIDFILE}" ]]; then
+		pkill -SIGTERM -F ${QEMU_PIDFILE} 2>&1 >/dev/null
+	fi
+}
+
+build() {
+	log_setup "Building kernel and tests"
+
+	pushd ${KERNEL_CHECKOUT} >/dev/null
+	vng \
+		--kconfig \
+		--config ${KERNEL_CHECKOUT}/tools/testing/selftests/vsock/config.vsock
+	make -j$(nproc)
+	make -C ${KERNEL_CHECKOUT}/tools/testing/vsock
+	popd >/dev/null

I think it would be better to avoid the kernel rebuild. A possible
alternative could be including in 'config' the needed knobs for vng's
sake and re-use the running kernel.

Cheers,

Paolo

Thanks Paolo, I'll incorporate your feedback in the next rev!

Best,
Bobby