A new functional test is added that exercises the code changes related to closing of the old KVM VM file descriptor and opening a new one upon VM reset. This normally happens when confidential guests are reset but for non-confidential guests, we use a special machine specific debug/test parameter 'x-change-vmfd-on-reset' to enable this behavior. Only specific code changes related to re-initialisation of SEV-ES, SEV-SNP and TDX platforms are not exercised in this test as they require hardware that supports running confidential guests.
Signed-off-by: Ani Sinha <[email protected]> --- MAINTAINERS | 1 + tests/functional/x86_64/meson.build | 1 + tests/functional/x86_64/test_rebuild_vmfd.py | 136 +++++++++++++++++++ 3 files changed, 138 insertions(+) create mode 100755 tests/functional/x86_64/test_rebuild_vmfd.py diff --git a/MAINTAINERS b/MAINTAINERS index 6377ff5898..726aa35ff2 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -157,6 +157,7 @@ M: Ani Sinha <[email protected]> M: Paolo Bonzini <[email protected]> S: Maintained F: stubs/kvm.c +F: tests/functional/x86_64/test_rebuild_vmfd.py Guest CPU cores (TCG) --------------------- diff --git a/tests/functional/x86_64/meson.build b/tests/functional/x86_64/meson.build index beab4f304b..05e4914c77 100644 --- a/tests/functional/x86_64/meson.build +++ b/tests/functional/x86_64/meson.build @@ -37,4 +37,5 @@ tests_x86_64_system_thorough = [ 'vhost_user_bridge', 'virtio_balloon', 'virtio_gpu', + 'rebuild_vmfd', ] diff --git a/tests/functional/x86_64/test_rebuild_vmfd.py b/tests/functional/x86_64/test_rebuild_vmfd.py new file mode 100755 index 0000000000..5a8e5fd89b --- /dev/null +++ b/tests/functional/x86_64/test_rebuild_vmfd.py @@ -0,0 +1,136 @@ +#!/usr/bin/env python3 +# +# Functional tests exercising guest KVM file descriptor change on reset. +# +# Copyright ?? 2026 Red Hat, Inc. +# +# Author: +# Ani Sinha <[email protected]> +# +# SPDX-License-Identifier: GPL-2.0-or-later + +import os +from qemu.machine import machine + +from qemu_test import QemuSystemTest, Asset, exec_command_and_wait_for_pattern +from qemu_test import wait_for_console_pattern + +class KVMGuest(QemuSystemTest): + + # ASSET UKI was generated using + # https://gitlab.com/kraxel/edk2-tests/-/blob/unittest/tools/make-supermin.sh + ASSET_UKI = Asset('https://gitlab.com/anisinha/misc-artifacts/' + '-/raw/main/uki.x86-64.efi?ref_type=heads', + 'e0f806bd1fa24111312e1fe849d2ee69808d4343930a5' + 'dc8c1688da17c65f576') + # ASSET_OVMF comes from /usr/share/edk2/ovmf/OVMF.stateless.fd of a + # fedora core 43 distribution which in turn comes from the + # edk2-ovmf-20251119-3.fc43.noarch rpm of that distribution. + ASSET_OVMF = Asset('https://gitlab.com/anisinha/misc-artifacts/' + '-/raw/main/OVMF.stateless.fd?ref_type=heads', + '58a4275aafa8774bd6b1540adceae4ea434b8db75b476' + '11839ff47be88cfcf22') + + def common_vm_setup(self, kvm_args=None, cpu_args=None): + self.set_machine('q35') + self.require_accelerator("kvm") + + self.vm.set_console() + if kvm_args: + self.vm.add_args("-accel", "kvm,%s" %kvm_args) + else: + self.vm.add_args("-accel", "kvm") + self.vm.add_args("-smp", "2") + if cpu_args: + self.vm.add_args("-cpu", "host,%s" %cpu_args) + else: + self.vm.add_args("-cpu", "host") + self.vm.add_args("-m", "2G") + self.vm.add_args("-nographic", "-nodefaults") + + + self.uki_path = self.ASSET_UKI.fetch() + self.ovmf_path = self.ASSET_OVMF.fetch() + + self.vm.add_args('-kernel', self.uki_path) + self.vm.add_args("-bios", self.ovmf_path) + # enable KVM VMFD change on reset for a non-coco VM + self.vm.add_args("-machine", "q35,x-change-vmfd-on-reset=on") + + # enable tracing of basic vmfd change function + self.vm.add_args("--trace", "kvm_reset_vmfd") + + def launch_vm(self): + try: + self.vm.launch() + except machine.VMLaunchFailure as e: + if "Xen HVM guest support not present" in e.output: + self.skipTest("KVM Xen support is not present " + "(need v5.12+ kernel with CONFIG_KVM_XEN)") + elif "Property 'kvm-accel.xen-version' not found" in e.output: + self.skipTest("QEMU not built with CONFIG_XEN_EMU support") + else: + raise e + + self.log.info('VM launched') + console_pattern = 'bash-5.1#' + wait_for_console_pattern(self, console_pattern) + self.log.info('VM ready with a bash prompt') + + def vm_console_reset(self): + exec_command_and_wait_for_pattern(self, '/usr/sbin/reboot -f', + 'reboot: machine restart') + console_pattern = '# --- Hello world ---' + wait_for_console_pattern(self, console_pattern) + self.vm.shutdown() + + def vm_qmp_reset(self): + self.vm.qmp('system_reset') + console_pattern = '# --- Hello world ---' + wait_for_console_pattern(self, console_pattern) + self.vm.shutdown() + + def check_logs(self): + self.assertRegex(self.vm.get_log(), + r'kvm_reset_vmfd') + self.assertRegex(self.vm.get_log(), + r'virtual machine state has been rebuilt') + + def test_reset_console(self): + self.common_vm_setup() + self.launch_vm() + self.vm_console_reset() + self.check_logs() + + def test_reset_qmp(self): + self.common_vm_setup() + self.launch_vm() + self.vm_qmp_reset() + self.check_logs() + + def test_reset_kvmpit(self): + self.common_vm_setup() + self.vm.add_args("--trace", "kvmpit_post_vmfd_change") + self.launch_vm() + self.vm_console_reset() + self.assertRegex(self.vm.get_log(), + r'kvmpit_post_vmfd_change') + + def test_reset_xen_emulation(self): + self.common_vm_setup("xen-version=0x4000a,kernel-irqchip=split") + self.launch_vm() + self.vm_console_reset() + self.check_logs() + + def test_reset_hyperv_vmbus(self): + self.common_vm_setup(None, "hv-syndbg,hv-relaxed,hv_time,hv-synic," + "hv-vpindex,hv-runtime,hv-stimer") + self.vm.add_args("-device", "vmbus-bridge,irq=15") + self.vm.add_args("-trace", "vmbus_handle_vmfd_change") + self.launch_vm() + self.vm_console_reset() + self.assertRegex(self.vm.get_log(), + r'vmbus_handle_vmfd_change') + +if __name__ == '__main__': + QemuSystemTest.main() -- 2.42.0
