[PATCH v5 8/8] tests/functional/x86_64: add migration test for NVMe device

[Alexander Mikhalitsyn <alexander@mihalicyn.com>]

From: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@futurfusion.io>

Introduce a very simple test to ensure that NVMe device
migration works fine.

Test plan is simple:
1. prepare VM with NVMe device
2. run workload that produces relatively heavy IO on the device
3. migrate VM
4. ensure that workload is alive and finishes without errors

Test can be run as simple as:
$ meson test 'func-x86_64-nvme_migration' --setup thorough -C build

In the future we can extend this approach, and introduce some
fio-based tests. And probably, it makes sense to make this test
to apply not only to NVMe device, but also virtio-{blk,scsi},
ide, sata and other migratable devices.

Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@futurfusion.io>
---
 tests/functional/x86_64/meson.build           |   1 +
 .../functional/x86_64/test_nvme_migration.py  | 159 ++++++++++++++++++
 2 files changed, 160 insertions(+)
 create mode 100755 tests/functional/x86_64/test_nvme_migration.py

diff --git a/tests/functional/x86_64/meson.build b/tests/functional/x86_64/meson.build
index 1ed10ad6c29..fd77f19d726 100644
--- a/tests/functional/x86_64/meson.build
+++ b/tests/functional/x86_64/meson.build
@@ -37,6 +37,7 @@ tests_x86_64_system_thorough = [
   'linux_initrd',
   'multiprocess',
   'netdev_ethtool',
+  'nvme_migration',
   'replay',
   'reverse_debug',
   'tuxrun',
diff --git a/tests/functional/x86_64/test_nvme_migration.py b/tests/functional/x86_64/test_nvme_migration.py
new file mode 100755
index 00000000000..3788a8e3473
--- /dev/null
+++ b/tests/functional/x86_64/test_nvme_migration.py
@@ -0,0 +1,159 @@
+#!/usr/bin/env python3
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# x86_64 NVMe migration test
+
+from migration import MigrationTest
+from qemu_test import QemuSystemTest, Asset
+from qemu_test import wait_for_console_pattern
+from qemu_test import exec_command, exec_command_and_wait_for_pattern
+
+
+class X8664NVMeMigrationTest(MigrationTest):
+    ASSET_KERNEL = Asset(
+        ('https://archives.fedoraproject.org/pub/archive/fedora/linux/releases'
+         '/31/Server/x86_64/os/images/pxeboot/vmlinuz'),
+        'd4738d03dbbe083ca610d0821d0a8f1488bebbdccef54ce33e3adb35fda00129')
+
+    ASSET_INITRD = Asset(
+        ('https://archives.fedoraproject.org/pub/archive/fedora/linux/releases'
+         '/31/Server/x86_64/os/images/pxeboot/initrd.img'),
+        '277cd6c7adf77c7e63d73bbb2cded8ef9e2d3a2f100000e92ff1f8396513cd8b')
+
+    ASSET_DISKIMAGE = Asset(
+        ('https://archives.fedoraproject.org/pub/archive/fedora/linux/releases'
+         '/31/Cloud/x86_64/images/Fedora-Cloud-Base-31-1.9.x86_64.qcow2'),
+        'e3c1b309d9203604922d6e255c2c5d098a309c2d46215d8fc026954f3c5c27a0')
+
+    DEFAULT_KERNEL_PARAMS = ('root=/dev/nvme0n1p1 console=ttyS0 net.ifnames=0 '
+                             'rd.rescue quiet')
+
+    def wait_for_console_pattern(self, success_message, vm):
+        wait_for_console_pattern(
+            self,
+            success_message,
+            failure_message="Kernel panic - not syncing",
+            vm=vm,
+        )
+
+    def exec_command_and_check(self, command, vm):
+        prompt = '# '
+        exec_command_and_wait_for_pattern(self,
+                                        f"{command} && echo OK || echo FAIL",
+                                        'FAIL', vm=vm)
+        # Note, that commands we send to the console are echo-ed back, so if we have a word "FAIL"
+        # in the command itself, we should expect to see it once.
+        wait_for_console_pattern(self, 'OK', failure_message="FAIL", vm=vm)
+        self.wait_for_console_pattern(prompt, vm)
+
+    def configure_machine(self, vm):
+        kernel_path = self.ASSET_KERNEL.fetch()
+        initrd_path = self.ASSET_INITRD.fetch()
+        diskimage_path = self.ASSET_DISKIMAGE.fetch()
+
+        vm.set_console()
+        vm.add_args("-cpu", "max")
+        vm.add_args("-m", "2G")
+        vm.add_args("-accel", "kvm")
+
+        vm.add_args('-drive',
+                         f'file={diskimage_path},if=none,id=drv0,snapshot=on')
+        vm.add_args('-device', 'nvme,bus=pcie.0,' +
+                         'drive=drv0,id=nvme-disk0,serial=nvmemigratetest,bootindex=1')
+
+        vm.add_args(
+            "-kernel",
+            kernel_path,
+            "-initrd",
+            initrd_path,
+            "-append",
+            self.DEFAULT_KERNEL_PARAMS
+        )
+
+    def launch_source_vm(self, vm):
+        vm.launch()
+
+        self.wait_for_console_pattern('Entering emergency mode.', vm)
+        prompt = '# '
+        self.wait_for_console_pattern(prompt, vm)
+
+        # Synchronize on NVMe driver creating the root device
+        exec_command_and_wait_for_pattern(self,
+                        "while ! (dmesg -c | grep nvme0n1:) ; do sleep 1 ; done",
+                        "nvme0n1", vm=vm)
+        self.wait_for_console_pattern(prompt, vm)
+
+        # prepare system
+        exec_command_and_wait_for_pattern(self, 'mount /dev/nvme0n1p1 /sysroot',
+                                          prompt, vm=vm)
+        exec_command_and_wait_for_pattern(self, 'chroot /sysroot',
+                                          prompt, vm=vm)
+        exec_command_and_wait_for_pattern(self, 'mount -t proc proc /proc',
+                                          prompt, vm=vm)
+        exec_command_and_wait_for_pattern(self, 'mount -t sysfs sysfs /sys',
+                                          prompt, vm=vm)
+
+        # Run workload before migration to check if it continues to run properly after migration
+        #
+        # Workload is simple: it continuously calculates checksums of all files in /usr/bin
+        # to generate some I/O load on the NVMe disk and at the same time it drops caches to
+        # make sure that we have some read I/O on the disk as well.
+        # If there are any issues with the migration of the NVMe device, we should see errors
+        # in dmesg and consequently in the workload log.
+        exec_command_and_wait_for_pattern(self,
+                                        "(while [ ! -f /tmp/test_nvme_migration_workload.stop ]; do \
+                                            rm -f /tmp/test_nvme_migration_workload.iteration_finished; \
+                                            echo 3 > /proc/sys/vm/drop_caches; \
+                                            find /usr/bin -type f -exec cksum {} \\;; \
+                                            touch /tmp/test_nvme_migration_workload.iteration_finished; \
+                                        done) > /dev/null 2> /tmp/test_nvme_migration_workload.errors &",
+                                        prompt, vm=vm)
+        exec_command_and_wait_for_pattern(self, 'echo $! > /tmp/test_nvme_migration_workload.pid',
+                                          prompt, vm=vm)
+
+        # check if process is alive and running
+        self.exec_command_and_check("kill -0 $(cat /tmp/test_nvme_migration_workload.pid)", vm)
+
+    def assert_dest_vm(self, vm):
+        prompt = '# '
+
+        # check if process is alive and running after migration, if not - fail the test
+        self.exec_command_and_check("kill -0 $(cat /tmp/test_nvme_migration_workload.pid)", vm)
+
+        # signal workload to stop
+        exec_command_and_wait_for_pattern(self, 'touch /tmp/test_nvme_migration_workload.stop',
+                                          prompt, vm=vm)
+
+        # wait workload to finish, because we want to examine log to see if there are any errors
+        exec_command_and_wait_for_pattern(self,
+                                        "while [ ! -f /tmp/test_nvme_migration_workload.iteration_finished ]; do sleep 1; done;",
+                                        prompt, vm=vm)
+
+        exec_command_and_wait_for_pattern(self, 'cat /tmp/test_nvme_migration_workload.errors',
+                                          prompt, vm=vm)
+
+        # fail the test if non-empty
+        self.exec_command_and_check("[ ! -s /tmp/test_nvme_migration_workload.errors ]", vm)
+
+    def test_migration_with_tcp_localhost(self):
+        self.set_machine('q35')
+        self.require_accelerator("kvm")
+
+        self.migration_with_tcp_localhost()
+
+    def test_migration_with_unix(self):
+        self.set_machine('q35')
+        self.require_accelerator("kvm")
+
+        self.migration_with_unix()
+
+    def test_migration_with_exec(self):
+        self.set_machine('q35')
+        self.require_accelerator("kvm")
+
+        self.migration_with_exec()
+
+
+if __name__ == '__main__':
+    MigrationTest.main()
-- 
2.47.3