On Tue, Jan 13, 2026 at 3:02 AM Yodel Eldar <[email protected]> wrote: > > Introduce a functional test of vhost-user-bridge and enter it into > MAINTAINERS under the vhost section. > > The test runs vhost-user-bridge as a subprocess, then launches a guest > with four backends: a unix domain socket for vhost-user, a UDP socket, a > user-mode net, and a hubport to hub the UDP and user backends; only the > vhost-user backend is exposed, the rest are deviceless. This > configuration mimics the testing setup described in the initial commit > of vhost-user-bridge in 3595e2eb0a23. > > A file containing a hardcoded UUID is created by the test in a scratch > file and exposed to the guest via the tftp parameter of the user netdev. > The guest requests the file by invoking tftp, and the test verifies its > sha256 hashsum. > > Similarly, a file containing another hardcoded UUID is created in the > guest. A call to check_http_download() serves the file via http to the > host and verifies integrity with its hashsum. > > Suggested-by: Cédric Le Goater <[email protected]> > Suggested-by: Marc-André Lureau <[email protected]> > Suggested-by: Michael S. Tsirkin <[email protected]> > Suggested-by: Thomas Huth <[email protected]> > Signed-off-by: Yodel Eldar <[email protected]>
Reviewed-by: Marc-André Lureau <[email protected]> by the way, have you left out adding the test to meson on purpose? +++ b/tests/functional/x86_64/meson.build @@ -36,4 +36,5 @@ tests_x86_64_system_thorough = [ 'vfio_user_client', 'virtio_balloon', 'virtio_gpu', + 'vhost_user_bridge', ] As I dig into the image creation process, I wonder if your approach will stand the test of time. It seems mkosi is the most promising project to create reproducible bootable images, and that we are moving to UKI instead of separate initramfs. Of course it's neat that you managed to put together a buildroot script that produces a 14Mb bzImage for the test, but it's also slow to build and perhaps not flexible enough if we generalize this approach to other built images in the future. > --- > MAINTAINERS | 1 + > .../x86_64/test_vhost_user_bridge.py | 147 ++++++++++++++++++ > 2 files changed, 148 insertions(+) > create mode 100755 tests/functional/x86_64/test_vhost_user_bridge.py > > diff --git a/MAINTAINERS b/MAINTAINERS > index 3a46c7fd0b..f41811d482 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -2374,32 +2374,33 @@ F: docs/devel/vfio-iommufd.rst > vhost > M: Michael S. Tsirkin <[email protected]> > R: Stefano Garzarella <[email protected]> > S: Supported > F: hw/*/*vhost* > F: docs/interop/vhost-user* > F: docs/system/devices/vhost-user* > F: contrib/vhost-user-*/ > F: backends/*vhost* > F: include/system/vhost-user-backend.h > F: include/hw/virtio/vhost* > F: include/*/vhost* > F: subprojects/libvhost-user/ > F: block/export/vhost-user* > F: util/vhost-user-server.c > F: net/vhost* > +F: tests/functional/x86_64/test_vhost_user_bridge.py > > vhost-shadow-virtqueue > R: Eugenio Pérez <[email protected]> > F: hw/virtio/vhost-shadow-virtqueue.* > > virtio > M: Michael S. Tsirkin <[email protected]> > S: Supported > F: hw/*/virtio* > F: hw/virtio/Makefile.objs > F: hw/virtio/trace-events > F: qapi/virtio.json > F: net/vhost-user.c > F: include/hw/virtio/ > F: docs/devel/virtio* > F: docs/devel/migration/virtio.rst > diff --git a/tests/functional/x86_64/test_vhost_user_bridge.py > b/tests/functional/x86_64/test_vhost_user_bridge.py > new file mode 100755 > index 0000000000..bf152dc959 > --- /dev/null > +++ b/tests/functional/x86_64/test_vhost_user_bridge.py > @@ -0,0 +1,147 @@ > +#!/usr/bin/env python3 > +# > +# Copyright (c) 2025 Software Freedom Conservancy, Inc. > +# > +# Author: Yodel Eldar <[email protected]> > +# > +# SPDX-License-Identifier: GPL-2.0-or-later > +""" > +Test vhost-user-bridge (vubr) functionality: > + > + 1) Run vhost-user-bridge on the host. > + 2) Launch a guest VM: > + a) Instantiate a unix domain socket to the vubr-created path > + b) Instantiate a vhost-user backend on top of that socket > + c) Map a virtio-net-pci device to the vhost-user backend > + d) Instantiate a UDP socket backend > + e) Instantiate a user-mode net backend > + i) Forward an ephemeral port to port 8080 in-guest with hostfwd= > + ii) Expose a generated scratch file to the guest with tftp= > + f) Hub the UDP and user-mode backends. > + 3) Invoke tftp in the guest to download exported scratch file from the > host. > + 4) Serve a file to the host via http server in the guest. > +""" > + > +import os > +import shutil > +import subprocess > +from qemu_test import Asset, LinuxKernelTest, which > +from qemu_test import exec_command_and_wait_for_pattern > +from qemu_test import is_readable_executable_file > +from qemu_test import wait_for_console_pattern > +from qemu_test.ports import Ports > + > +class VhostUserBridge(LinuxKernelTest): > + > + ASSET_KERNEL_INITRAMFS = Asset( > + > "https://github.com/yodel/vhost-user-bridge-test/raw/refs/heads/main/bzImage";, > + "8860d7aa59434f483542cdf25b42eacae0d4d4aa7ec923af9589d1ad4703d42b") > + > + HOST_UUID = "ba4c2e39-627f-487d-ae3b-93cc5d783eb8" > + HOST_UUID_HSUM = \ > + "d2932e34bf6c17b33e7325140b691e27c191d9ac4dfa550f68c09506facb09b9" > + > + GUEST_UUID = "143d2b21-fdf0-4c5e-a9ef-f35ebbac8945" > + GUEST_UUID_HSUM = \ > + "14b64203f5cf2afe520f8be0fdfe630aafc1e85d1301f55a0d1681e68881f3a2" > + > + def configure_vm(self, ud_socket_path, lport, rport, hostfwd_port, > tftpdir): > + self.require_accelerator("kvm") > + self.require_netdev("vhost-user") > + self.require_netdev("socket") > + self.require_netdev("hubport") > + self.require_netdev("user") > + self.require_device("virtio-net-pci") > + self.set_machine("q35") > + self.vm.add_args( > + "-cpu", "host", > + "-accel", "kvm", > + "-append", "printk.time=0 console=ttyS0", > + "-smp", "2", > + "-m", "128M", > + "-object", "memory-backend-memfd,id=mem0," > + "size=128M,share=on,prealloc=on", > + "-numa", "node,memdev=mem0", > + "-chardev", f"socket,id=char0,path={ud_socket_path}", > + "-netdev", "vhost-user,id=vhost0,chardev=char0,vhostforce=on", > + "-device", "virtio-net-pci,netdev=vhost0", > + "-netdev", f"socket,id=udp0,udp=localhost:{lport}," > + f"localaddr=localhost:{rport}", > + "-netdev", "hubport,id=hub0,hubid=0,netdev=udp0", > + "-netdev", "user,id=user0," > + f"hostfwd=tcp:127.0.0.1:{hostfwd_port}-:8080," > + f"tftp={tftpdir}", > + "-netdev", "hubport,id=hub1,hubid=0,netdev=user0" > + ) > + > + def assemble_vubr_args(self, vubr_path, ud_socket_path, lport, rport): > + vubr_args = [] > + > + if (stdbuf_path := which("stdbuf")) is None: > + self.log.info("Could not find stdbuf: vhost-user-bridge " > + "log lines may appear out of order") > + else: > + vubr_args += [stdbuf_path, "-o0", "-e0"] > + > + vubr_args += [vubr_path, "-u", f"{ud_socket_path}", > + "-l", f"127.0.0.1:{lport}", "-r", f"127.0.0.1:{rport}"] > + > + return vubr_args > + > + def test_vhost_user_bridge(self): > + prompt = "~ # " > + host_uuid_filename = "vubr-test-uuid.txt" > + guest_uuid_path = "/tmp/uuid.txt" > + kernel_path = self.ASSET_KERNEL_INITRAMFS.fetch() > + > + vubr_path = self.build_file("contrib", "vhost-user-bridge", > + "vhost-user-bridge") > + if is_readable_executable_file(vubr_path) is None: > + self.skipTest("Could not find a readable and executable " > + "vhost-user-bridge") > + > + vubr_log_path = self.log_file("vhost-user-bridge.log") > + self.log.info("For the vhost-user-bridge application log," > + f" see: {vubr_log_path}") > + > + sock_dir = self.socket_dir() > + ud_socket_path = os.path.join(sock_dir.name, "vubr-test.sock") > + > + tftpdir = self.scratch_file("tftp") > + shutil.rmtree(tftpdir, ignore_errors=True) > + os.mkdir(tftpdir) > + host_uuid_path = self.scratch_file("tftp", host_uuid_filename) > + with open(host_uuid_path, "w") as host_uuid_file: > + host_uuid_file.write(self.HOST_UUID) > + > + with Ports() as ports: > + lport, rport, hostfwd_port = ports.find_free_ports(3) > + > + self.configure_vm(ud_socket_path, lport, rport, hostfwd_port, > + tftpdir) > + > + vubr_args = self.assemble_vubr_args(vubr_path, ud_socket_path, > + lport, rport) > + > + with open(vubr_log_path, "w+") as vubr_log, \ > + subprocess.Popen(vubr_args, stdin=subprocess.DEVNULL, > + stdout=vubr_log, > + stderr=subprocess.STDOUT) as vubr_proc: > + self.launch_kernel(kernel_path, wait_for=prompt) > + > + exec_command_and_wait_for_pattern(self, > + f"tftp -g -r {host_uuid_filename} 10.0.2.2 ; " > + f"sha256sum {host_uuid_filename}", self.HOST_UUID_HSUM) > + wait_for_console_pattern(self, prompt) > + > + exec_command_and_wait_for_pattern(self, > + f"echo -n '{self.GUEST_UUID}' > {guest_uuid_path}", > prompt) > + self.check_http_download(guest_uuid_path, > self.GUEST_UUID_HSUM) > + wait_for_console_pattern(self, prompt) > + > + self.vm.shutdown() > + vubr_proc.terminate() > + vubr_proc.wait() > + > +if __name__ == '__main__': > + LinuxKernelTest.main() > -- > 2.52.0 > -- Marc-André Lureau
