tests/functional: Add PCI hotplug test for aarch64

Add a functional test, aarch64_hotplug_pci, to exercise PCI hotplug and
hot-unplug on arm64.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Thomas Huth <thuth@redhat.com>
Message-ID: <20250528203137.1654964-1-gustavo.romero@linaro.org>
[AJB: trimmed boilerplate for checkpatch, simplified invocations]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-ID: <20250627112512.1880708-3-alex.bennee@linaro.org>

MAINTAINERS

@@ -2089,6 +2089,12 @@ S: Supported
 F: include/hw/pci/pcie_doe.h
 F: hw/pci/pcie_doe.c
 
+ARM PCI Hotplug
+M: Gustavo Romero <gustavo.romero@linaro.org>
+L: qemu-arm@nongnu.org
+S: Supported
+F: tests/functional/test_aarch64_hotplug_pci.py
+
 ACPI/SMBIOS
 M: Michael S. Tsirkin <mst@redhat.com>
 M: Igor Mammedov <imammedo@redhat.com>

tests/functional/meson.build

@@ -83,6 +83,7 @@ tests_aarch64_system_quick = [
 tests_aarch64_system_thorough = [
   'aarch64_aspeed_ast2700',
   'aarch64_aspeed_ast2700fc',
+  'aarch64_hotplug_pci',
   'aarch64_imx8mp_evk',
   'aarch64_raspi3',
   'aarch64_raspi4',

tests/functional/test_aarch64_hotplug_pci.py

@@ -0,0 +1,72 @@
+#!/usr/bin/env python3
+#
+# The test hotplugs a PCI device and checks it on a Linux guest.
+#
+# Copyright (c) 2025 Linaro Ltd.
+#
+# Author:
+#  Gustavo Romero <gustavo.romero@linaro.org>
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+from qemu_test import LinuxKernelTest, Asset, exec_command_and_wait_for_pattern
+from qemu_test import BUILD_DIR
+
+class HotplugPCI(LinuxKernelTest):
+
+    ASSET_KERNEL = Asset(
+        ('https://ftp.debian.org/debian/dists/stable/main/installer-arm64/'
+         '20230607+deb12u11/images/netboot/debian-installer/arm64/linux'),
+         'd92a60392ce1e379ca198a1a820899f8f0d39a62d047c41ab79492f81541a9d9')
+
+    ASSET_INITRD = Asset(
+        ('https://ftp.debian.org/debian/dists/stable/main/installer-arm64/'
+         '20230607+deb12u11/images/netboot/debian-installer/arm64/initrd.gz'),
+         '9f817f76951f3237bca8216bee35267bfb826815687f4b2fcdd5e6c2a917790c')
+
+    def test_hotplug_pci(self):
+
+        self.set_machine('virt')
+
+        self.vm.add_args('-m', '512M',
+                         '-cpu', 'cortex-a57',
+                         '-append',
+                         'console=ttyAMA0,115200 init=/bin/sh',
+                         '-device',
+                         'pcie-root-port,bus=pcie.0,chassis=1,slot=1,id=pcie.1',
+                         '-bios',
+                         self.build_file('pc-bios', 'edk2-aarch64-code.fd'))
+
+        # BusyBox prompt
+        prompt = "~ #"
+        self.launch_kernel(self.ASSET_KERNEL.fetch(),
+                           self.ASSET_INITRD.fetch(),
+                           wait_for=prompt)
+
+        # Check for initial state: 2 network adapters, lo and enp0s1.
+        exec_command_and_wait_for_pattern(self,
+                                          'ls /sys/class/net | wc -l',
+                                          '2')
+
+        # Hotplug one network adapter to the root port, i.e. pcie.1 bus.
+        self.vm.cmd('device_add',
+                    driver='virtio-net-pci',
+                    bus='pcie.1',
+                    addr=0,
+                    id='na')
+        # Wait for the kernel to recognize the new device.
+        self.wait_for_console_pattern('virtio-pci')
+        self.wait_for_console_pattern('virtio_net')
+
+        # Check if there is a new network adapter.
+        exec_command_and_wait_for_pattern(self,
+                                          'ls /sys/class/net | wc -l',
+                                          '3')
+
+        self.vm.cmd('device_del', id='na')
+        exec_command_and_wait_for_pattern(self,
+                                          'ls /sys/class/net | wc -l',
+                                          '2')
+
+if __name__ == '__main__':
+    LinuxKernelTest.main()