tests/acceptance: add base class record/replay kernel tests

This patch adds a base for testing kernel boot recording and replaying.
Each test has the phase of recording and phase of replaying.
Virtual machines just boot the kernel and do not interact with
the network.
Structure and image links for the tests are borrowed from boot_linux_console.py
Testing controls the message pattern at the end of the kernel
boot for both record and replay modes. In replay mode QEMU is also
intended to finish the execution automatically.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Tested-by: Philippe Mathieu-Daude <philmd@redhat.com>
Message-Id: <159073589099.20809.14078431743098373301.stgit@pasha-ThinkPad-X280>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[PMD: Keep imports sorted alphabetically]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

MAINTAINERS

@@ -2534,6 +2534,7 @@ F: net/filter-replay.c
 F: include/sysemu/replay.h
 F: docs/replay.txt
 F: stubs/replay.c
+F: tests/acceptance/replay_kernel.py
 
 IOVA Tree
 M: Peter Xu <peterx@redhat.com>

tests/acceptance/replay_kernel.py

@@ -0,0 +1,73 @@
+# Record/replay test that boots a Linux kernel
+#
+# Copyright (c) 2020 ISP RAS
+#
+# Author:
+#  Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
+#
+# This work is licensed under the terms of the GNU GPL, version 2 or
+# later.  See the COPYING file in the top-level directory.
+
+import os
+import logging
+import time
+
+from avocado_qemu import wait_for_console_pattern
+from avocado.utils import archive
+from avocado.utils import process
+from boot_linux_console import LinuxKernelTest
+
+class ReplayKernel(LinuxKernelTest):
+    """
+    Boots a Linux kernel in record mode and checks that the console
+    is operational and the kernel command line is properly passed
+    from QEMU to the kernel.
+    Then replays the same scenario and verifies, that QEMU correctly
+    terminates.
+    """
+
+    timeout = 90
+    KERNEL_COMMON_COMMAND_LINE = 'printk.time=1 panic=-1 '
+
+    def run_vm(self, kernel_path, kernel_command_line, console_pattern,
+               record, shift, args, replay_path):
+        logger = logging.getLogger('replay')
+        start_time = time.time()
+        vm = self.get_vm()
+        vm.set_console()
+        if record:
+            logger.info('recording the execution...')
+            mode = 'record'
+        else:
+            logger.info('replaying the execution...')
+            mode = 'replay'
+        vm.add_args('-icount', 'shift=%s,rr=%s,rrfile=%s' %
+                    (shift, mode, replay_path),
+                    '-kernel', kernel_path,
+                    '-append', kernel_command_line,
+                    '-net', 'none',
+                    '-no-reboot')
+        if args:
+            vm.add_args(*args)
+        vm.launch()
+        self.wait_for_console_pattern(console_pattern, vm)
+        if record:
+            vm.shutdown()
+            logger.info('finished the recording with log size %s bytes'
+                        % os.path.getsize(replay_path))
+        else:
+            vm.wait()
+            logger.info('successfully finished the replay')
+        elapsed = time.time() - start_time
+        logger.info('elapsed time %.2f sec' % elapsed)
+        return elapsed
+
+    def run_rr(self, kernel_path, kernel_command_line, console_pattern,
+               shift=7, args=None):
+        replay_path = os.path.join(self.workdir, 'replay.bin')
+        t1 = self.run_vm(kernel_path, kernel_command_line, console_pattern,
+                         True, shift, args, replay_path)
+        t2 = self.run_vm(kernel_path, kernel_command_line, console_pattern,
+                         False, shift, args, replay_path)
+        logger = logging.getLogger('replay')
+        logger.info('replay overhead {:.2%}'.format(t2 / t1 - 1))