diff --git a/MAINTAINERS b/MAINTAINERS
index ee058e2fef..93cef88f46 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4423,6 +4423,7 @@ Functional testing framework
 M: Thomas Huth <thuth@redhat.com>
 R: Philippe Mathieu-Daudé <philmd@linaro.org>
 R: Daniel P. Berrange <berrange@redhat.com>
+S: Maintained
 F: docs/devel/testing/functional.rst
 F: scripts/clean_functional_cache.py
 F: tests/functional/qemu_test/
diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c
index a3bb5aa221..5841dfc4fe 100644
--- a/hw/s390x/s390-pci-inst.c
+++ b/hw/s390x/s390-pci-inst.c
@@ -396,7 +396,7 @@ static MemoryRegion *s390_get_subregion(MemoryRegion *mr, uint64_t offset,
     uint64_t subregion_size;
 
     QTAILQ_FOREACH(subregion, &mr->subregions, subregions_link) {
-        subregion_size = int128_get64(subregion->size);
+        subregion_size = memory_region_size(subregion);
         if ((offset >= subregion->addr) &&
             (offset + len) <= (subregion->addr + subregion_size)) {
             mr = subregion;
diff --git a/scripts/device-crash-test b/scripts/device-crash-test
index 1ecb9663ae..c1576e8b96 100755
--- a/scripts/device-crash-test
+++ b/scripts/device-crash-test
@@ -527,7 +527,7 @@ def main():
         # Async QMP, when in use, is chatty about connection failures.
         # This script knowingly generates a ton of connection errors.
         # Silence this logger.
-        logging.getLogger('qemu.qmp.qmp_client').setLevel(logging.CRITICAL)
+        logging.getLogger('qemu.qmp.protocol').setLevel(logging.CRITICAL)
 
     fatal_failures = []
     wl_stats = {}
diff --git a/target/s390x/tcg/mem_helper.c b/target/s390x/tcg/mem_helper.c
index f1acb1618f..24675fc818 100644
--- a/target/s390x/tcg/mem_helper.c
+++ b/target/s390x/tcg/mem_helper.c
@@ -1959,6 +1959,10 @@ void HELPER(lctlg)(CPUS390XState *env, uint32_t r1, uint64_t a2, uint32_t r3)
         if (env->cregs[i] != val && i >= 9 && i <= 11) {
             PERchanged = true;
         }
+        if (i == 0 && !(env->cregs[i] & CR0_CKC_SC) && (val & CR0_CKC_SC)) {
+            BQL_LOCK_GUARD();
+            tcg_s390_tod_updated(env_cpu(env), RUN_ON_CPU_NULL);
+        }
         env->cregs[i] = val;
         HELPER_LOG("load ctl %d from 0x%" PRIx64 " == 0x%" PRIx64 "\n",
                    i, src, val);
@@ -1989,10 +1993,15 @@ void HELPER(lctl)(CPUS390XState *env, uint32_t r1, uint64_t a2, uint32_t r3)
 
     for (i = r1;; i = (i + 1) % 16) {
         uint32_t val = cpu_ldl_data_ra(env, src, ra);
+        uint64_t val64 = deposit64(env->cregs[i], 0, 32, val);
         if ((uint32_t)env->cregs[i] != val && i >= 9 && i <= 11) {
             PERchanged = true;
         }
-        env->cregs[i] = deposit64(env->cregs[i], 0, 32, val);
+        if (i == 0 && !(env->cregs[i] & CR0_CKC_SC) && (val64 & CR0_CKC_SC)) {
+            BQL_LOCK_GUARD();
+            tcg_s390_tod_updated(env_cpu(env), RUN_ON_CPU_NULL);
+        }
+        env->cregs[i] = val64;
         HELPER_LOG("load ctl %d from 0x%" PRIx64 " == 0x%x\n", i, src, val);
         src += sizeof(uint32_t);
 
diff --git a/target/s390x/tcg/misc_helper.c b/target/s390x/tcg/misc_helper.c
index 6d9d601d29..215b5b9d93 100644
--- a/target/s390x/tcg/misc_helper.c
+++ b/target/s390x/tcg/misc_helper.c
@@ -199,11 +199,15 @@ static void update_ckc_timer(CPUS390XState *env)
         return;
     }
 
-    /* difference between origins */
-    time = env->ckc - td->base.low;
+    if (env->ckc < td->base.low) {
+        time = 0;
+    } else {
+        /* difference between origins */
+        time = env->ckc - td->base.low;
 
-    /* nanoseconds */
-    time = tod2time(time);
+        /* nanoseconds */
+        time = tod2time(time);
+    }
 
     timer_mod(env->tod_timer, time);
 }
diff --git a/target/s390x/tcg/translate.c b/target/s390x/tcg/translate.c
index ec9e5a0751..4d2b8c5e2b 100644
--- a/target/s390x/tcg/translate.c
+++ b/target/s390x/tcg/translate.c
@@ -5613,6 +5613,7 @@ static void in2_r2_nz(DisasContext *s, DisasOps *o)
     int r2 = get_field(s, r2);
     if (r2 != 0) {
         o->in2 = load_reg(r2);
+        gen_addi_and_wrap_i64(s, o->in2, o->in2, 0);
     }
 }
 #define SPEC_in2_r2_nz 0
@@ -6379,10 +6380,12 @@ static void s390x_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
 {
     DisasContext *dc = container_of(dcbase, DisasContext, base);
 
-    /* 31-bit mode */
-    if (!(dc->base.tb->flags & FLAG_MASK_64)) {
-        dc->base.pc_first &= 0x7fffffff;
-        dc->base.pc_next = dc->base.pc_first;
+    if (dc->base.tb->flags & FLAG_MASK_32) {
+        if (!(dc->base.tb->flags & FLAG_MASK_64)) {
+            assert(!(dc->base.pc_first & ~((1ULL << 31) - 1)));
+        }
+    } else {
+        assert(!(dc->base.pc_first & ~((1ULL << 24) - 1)));
     }
 
     dc->cc_op = CC_OP_DYNAMIC;
diff --git a/tests/functional/arm/test_aspeed_ast1030.py b/tests/functional/arm/test_aspeed_ast1030.py
index 60e2b0251c..d1822edd8f 100755
--- a/tests/functional/arm/test_aspeed_ast1030.py
+++ b/tests/functional/arm/test_aspeed_ast1030.py
@@ -6,9 +6,8 @@
 #
 # SPDX-License-Identifier: GPL-2.0-or-later
 
-from qemu_test import LinuxKernelTest, Asset
 from aspeed import AspeedTest
-from qemu_test import exec_command_and_wait_for_pattern
+from qemu_test import Asset, exec_command_and_wait_for_pattern
 
 
 class AST1030Machine(AspeedTest):
diff --git a/tests/functional/migration.py b/tests/functional/migration.py
index 0739554483..2bfb1f7790 100644
--- a/tests/functional/migration.py
+++ b/tests/functional/migration.py
@@ -30,11 +30,11 @@ class MigrationTest(QemuSystemTest):
 
         end = time.monotonic() + self.timeout
         while time.monotonic() < end and not self.migration_finished(src_vm):
-           time.sleep(0.1)
+            time.sleep(0.1)
 
         end = time.monotonic() + self.timeout
         while time.monotonic() < end and not self.migration_finished(dst_vm):
-           time.sleep(0.1)
+            time.sleep(0.1)
 
         self.assertEqual(src_vm.cmd('query-migrate')['status'], 'completed')
         self.assertEqual(dst_vm.cmd('query-migrate')['status'], 'completed')
diff --git a/tests/functional/ppc/test_74xx.py b/tests/functional/ppc/test_74xx.py
index 5386016f26..219c7991ac 100755
--- a/tests/functional/ppc/test_74xx.py
+++ b/tests/functional/ppc/test_74xx.py
@@ -10,7 +10,7 @@
 from qemu_test import QemuSystemTest
 from qemu_test import wait_for_console_pattern
 
-class ppc74xxCpu(QemuSystemTest):
+class Ppc74xxCpu(QemuSystemTest):
 
     timeout = 5
 
diff --git a/tests/functional/ppc/test_sam460ex.py b/tests/functional/ppc/test_sam460ex.py
index 31cf9dd6de..024406d155 100755
--- a/tests/functional/ppc/test_sam460ex.py
+++ b/tests/functional/ppc/test_sam460ex.py
@@ -8,10 +8,11 @@ from qemu_test import LinuxKernelTest, Asset
 from qemu_test import exec_command_and_wait_for_pattern
 
 
-class sam460exTest(LinuxKernelTest):
+class Sam460exTest(LinuxKernelTest):
 
     ASSET_BR2_SAM460EX_LINUX = Asset(
-        'https://github.com/legoater/qemu-ppc-boot/raw/refs/heads/main/buildroot/qemu_ppc_sam460ex-2023.11-8-gdcd9f0f6eb-20240105/vmlinux',
+        ('https://github.com/legoater/qemu-ppc-boot/raw/refs/heads/main'
+         '/buildroot/qemu_ppc_sam460ex-2023.11-8-gdcd9f0f6eb-20240105/vmlinux'),
         '6f46346f3e20e8b5fc050ff363f350f8b9d76a051b9e0bd7ea470cc680c14df2')
 
     def test_ppc_sam460ex_buildroot(self):
diff --git a/tests/functional/ppc64/test_mac99.py b/tests/functional/ppc64/test_mac99.py
index dfd9c01371..a3261a8330 100755
--- a/tests/functional/ppc64/test_mac99.py
+++ b/tests/functional/ppc64/test_mac99.py
@@ -7,14 +7,16 @@
 from qemu_test import LinuxKernelTest, Asset
 from qemu_test import exec_command_and_wait_for_pattern
 
-class mac99Test(LinuxKernelTest):
+class Mac99Test(LinuxKernelTest):
 
     ASSET_BR2_MAC99_LINUX = Asset(
-        'https://github.com/legoater/qemu-ppc-boot/raw/refs/heads/main/buildroot/qemu_ppc64_mac99-2023.11-8-gdcd9f0f6eb-20240105/vmlinux',
+        ('https://github.com/legoater/qemu-ppc-boot/raw/refs/heads/main'
+         '/buildroot/qemu_ppc64_mac99-2023.11-8-gdcd9f0f6eb-20240105/vmlinux'),
         'd59307437e4365f2cced0bbd1b04949f7397b282ef349b7cafd894d74aadfbff')
 
     ASSET_BR2_MAC99_ROOTFS = Asset(
-        'https://github.com/legoater/qemu-ppc-boot/raw/refs/heads/main//buildroot/qemu_ppc64_mac99-2023.11-8-gdcd9f0f6eb-20240105/rootfs.ext2',
+        ('https://github.com/legoater/qemu-ppc-boot/raw/refs/heads/main'
+         '/buildroot/qemu_ppc64_mac99-2023.11-8-gdcd9f0f6eb-20240105/rootfs.ext2'),
         'bbd5fd8af62f580bc4e585f326fe584e22856572633a8333178ea6d4ed4955a4')
 
     def test_ppc64_mac99_buildroot(self):
diff --git a/tests/functional/ppc64/test_powernv.py b/tests/functional/ppc64/test_powernv.py
index 9ada832b78..0ea6c93e42 100755
--- a/tests/functional/ppc64/test_powernv.py
+++ b/tests/functional/ppc64/test_powernv.py
@@ -10,7 +10,7 @@
 from qemu_test import LinuxKernelTest, Asset
 from qemu_test import wait_for_console_pattern
 
-class powernvMachine(LinuxKernelTest):
+class PowernvMachine(LinuxKernelTest):
 
     timeout = 90
     KERNEL_COMMON_COMMAND_LINE = 'printk.time=0 console=hvc0 '
diff --git a/tests/functional/ppc64/test_pseries.py b/tests/functional/ppc64/test_pseries.py
index 67057934e8..7840c4e3ff 100755
--- a/tests/functional/ppc64/test_pseries.py
+++ b/tests/functional/ppc64/test_pseries.py
@@ -10,7 +10,7 @@
 from qemu_test import QemuSystemTest, Asset
 from qemu_test import wait_for_console_pattern
 
-class pseriesMachine(QemuSystemTest):
+class PseriesMachine(QemuSystemTest):
 
     timeout = 90
     KERNEL_COMMON_COMMAND_LINE = 'printk.time=0 console=hvc0 '
diff --git a/tests/functional/ppc64/test_reverse_debug.py b/tests/functional/ppc64/test_reverse_debug.py
index 69551fb84d..4eef779936 100755
--- a/tests/functional/ppc64/test_reverse_debug.py
+++ b/tests/functional/ppc64/test_reverse_debug.py
@@ -18,7 +18,7 @@ from qemu_test import skipFlakyTest
 from reverse_debugging import ReverseDebugging
 
 
-class ReverseDebugging_ppc64(ReverseDebugging):
+class ReverseDebuggingPpc64(ReverseDebugging):
 
     @skipFlakyTest("https://gitlab.com/qemu-project/qemu/-/issues/1992")
     def test_ppc64_pseries(self):
diff --git a/tests/functional/qemu_test/asset.py b/tests/functional/qemu_test/asset.py
index ab3a7bb591..bae40765ce 100644
--- a/tests/functional/qemu_test/asset.py
+++ b/tests/functional/qemu_test/asset.py
@@ -112,7 +112,7 @@ class Asset:
                 return False
 
         self.log.debug("Time out while waiting for %s!", tmp_cache_file)
-        raise
+        raise TimeoutError(f"Time out while waiting for {tmp_cache_file}")
 
     def _save_time_stamp(self):
         '''
@@ -141,7 +141,7 @@ class Asset:
         self.log.info("Downloading %s to %s...", self.url, self.cache_file)
         tmp_cache_file = self.cache_file.with_suffix(".download")
 
-        for retries in range(3):
+        for _retries in range(3):
             try:
                 with tmp_cache_file.open("xb") as dst:
                     with urllib.request.urlopen(self.url) as resp:
@@ -181,7 +181,7 @@ class Asset:
                 # server or networking problem
                 if e.code == 404:
                     raise AssetError(self, "Unable to download: "
-                                     "HTTP error %d" % e.code)
+                                     "HTTP error %d" % e.code) from e
                 continue
             except URLError as e:
                 # This is typically a network/service level error
@@ -190,7 +190,7 @@ class Asset:
                 self.log.error("Unable to download %s: URL error %s",
                                self.url, e.reason)
                 raise AssetError(self, "Unable to download: URL error %s" %
-                                 e.reason, transient=True)
+                                 e.reason, transient=True) from e
             except ConnectionError as e:
                 # A socket connection failure, such as dropped conn
                 # or refused conn
@@ -201,7 +201,7 @@ class Asset:
             except Exception as e:
                 tmp_cache_file.unlink()
                 raise AssetError(self, "Unable to download: %s" % e,
-                                 transient=True)
+                                 transient=True) from e
 
         if not os.path.exists(tmp_cache_file):
             raise AssetError(self, "Download retries exceeded", transient=True)
@@ -214,7 +214,6 @@ class Asset:
                         self.hash.encode('utf8'))
         except Exception as e:
             self.log.debug("Unable to set xattr on %s: %s", tmp_cache_file, e)
-            pass
 
         if not self._check(tmp_cache_file):
             tmp_cache_file.unlink()
@@ -224,9 +223,10 @@ class Asset:
         # Remove write perms to stop tests accidentally modifying them
         os.chmod(self.cache_file, stat.S_IRUSR | stat.S_IRGRP)
 
-        self.log.info("Cached %s at %s" % (self.url, self.cache_file))
+        self.log.info("Cached %s at %s", self.url, self.cache_file)
         return str(self.cache_file)
 
+    @staticmethod
     def precache_test(test):
         log = logging.getLogger('qemu-test')
         log.setLevel(logging.DEBUG)
@@ -237,16 +237,17 @@ class Asset:
         handler.setFormatter(formatter)
         log.addHandler(handler)
         for name, asset in vars(test.__class__).items():
-            if name.startswith("ASSET_") and type(asset) == Asset:
+            if name.startswith("ASSET_") and isinstance(asset, Asset):
                 try:
                     asset.fetch()
                 except AssetError as e:
                     if not e.transient:
                         raise
-                    log.error("%s: skipping asset precache" % e)
+                    log.error("%s: skipping asset precache", e)
 
         log.removeHandler(handler)
 
+    @staticmethod
     def precache_suite(suite):
         for test in suite:
             if isinstance(test, unittest.TestSuite):
@@ -254,9 +255,10 @@ class Asset:
             elif isinstance(test, unittest.TestCase):
                 Asset.precache_test(test)
 
-    def precache_suites(path, cacheTstamp):
+    @staticmethod
+    def precache_suites(path, cache_tstamp):
         loader = unittest.loader.defaultTestLoader
         tests = loader.loadTestsFromNames([path], None)
 
-        with open(cacheTstamp, "w") as fh:
+        with open(cache_tstamp, "w", encoding='utf-8'):
             Asset.precache_suite(tests)
diff --git a/tests/functional/qemu_test/decorators.py b/tests/functional/qemu_test/decorators.py
index b239295804..807418359a 100644
--- a/tests/functional/qemu_test/decorators.py
+++ b/tests/functional/qemu_test/decorators.py
@@ -10,136 +10,134 @@ from unittest import skipIf, skipUnless
 
 from .cmd import which
 
-'''
-Decorator to skip execution of a test if the provided
-environment variables are not set.
-Example:
 
-  @skipIfMissingEnv("QEMU_ENV_VAR0", "QEMU_ENV_VAR1")
-'''
 def skipIfMissingEnv(*vars_):
+    '''
+    Decorator to skip execution of a test if the provided
+    environment variables are not set.
+    Example:
+
+      @skipIfMissingEnv("QEMU_ENV_VAR0", "QEMU_ENV_VAR1")
+    '''
     missing_vars = []
     for var in vars_:
-        if os.getenv(var) == None:
+        if os.getenv(var) is None:
             missing_vars.append(var)
 
-    has_vars = True if len(missing_vars) == 0 else False
+    has_vars = len(missing_vars) == 0
 
     return skipUnless(has_vars, f"Missing env var(s): {', '.join(missing_vars)}")
 
-'''
-
-Decorator to skip execution of a test if the list
-of command binaries is not available in $PATH.
-Example:
-
-  @skipIfMissingCommands("mkisofs", "losetup")
-'''
 def skipIfMissingCommands(*args):
+    '''
+    Decorator to skip execution of a test if the list
+    of command binaries is not available in $PATH.
+    Example:
+
+      @skipIfMissingCommands("mkisofs", "losetup")
+    '''
     has_cmds = True
     for cmd in args:
-         if not which(cmd):
-             has_cmds = False
-             break
+        if not which(cmd):
+            has_cmds = False
+            break
 
     return skipUnless(has_cmds, 'required command(s) "%s" not installed' %
                                 ", ".join(args))
 
-'''
-Decorator to skip execution of a test if the current
-host operating system does match one of the prohibited
-ones.
-Example
-
-  @skipIfOperatingSystem("Linux", "Darwin")
-'''
 def skipIfOperatingSystem(*args):
+    '''
+    Decorator to skip execution of a test if the current host
+    operating system does match one of the prohibited ones.
+    Example:
+
+      @skipIfOperatingSystem("Linux", "Darwin")
+    '''
     return skipIf(platform.system() in args,
                   'running on an OS (%s) that is not able to run this test' %
                   ", ".join(args))
 
-'''
-Decorator to skip execution of a test if the current
-host machine does not match one of the permitted
-machines.
-Example
-
-  @skipIfNotMachine("x86_64", "aarch64")
-'''
 def skipIfNotMachine(*args):
+    '''
+    Decorator to skip execution of a test if the current
+    host machine does not match one of the permitted machines.
+    Example:
+
+      @skipIfNotMachine("x86_64", "aarch64")
+    '''
     return skipUnless(platform.machine() in args,
                       'not running on one of the required machine(s) "%s"' %
                       ", ".join(args))
 
-'''
-Decorator to skip execution of flaky tests, unless
-the $QEMU_TEST_FLAKY_TESTS environment variable is set.
-A bug URL must be provided that documents the observed
-failure behaviour, so it can be tracked & re-evaluated
-in future.
-
-Historical tests may be providing "None" as the bug_url
-but this should not be done for new test.
-
-Example:
-
-  @skipFlakyTest("https://gitlab.com/qemu-project/qemu/-/issues/NNN")
-'''
 def skipFlakyTest(bug_url):
+    '''
+    Decorator to skip execution of flaky tests, unless
+    the $QEMU_TEST_FLAKY_TESTS environment variable is set.
+    A bug URL must be provided that documents the observed
+    failure behaviour, so it can be tracked & re-evaluated
+    in future.
+
+    Historical tests may be providing "None" as the bug_url
+    but this should not be done for new test.
+
+    Example:
+
+      @skipFlakyTest("https://gitlab.com/qemu-project/qemu/-/issues/NNN")
+    '''
     if bug_url is None:
         bug_url = "FIXME: reproduce flaky test and file bug report or remove"
     return skipUnless(os.getenv('QEMU_TEST_FLAKY_TESTS'),
                       f'Test is unstable: {bug_url}')
 
-'''
-Decorator to skip execution of tests which are likely
-to execute untrusted commands on the host, or commands
-which process untrusted code, unless the
-$QEMU_TEST_ALLOW_UNTRUSTED_CODE env var is set.
-Example:
-
-  @skipUntrustedTest()
-'''
 def skipUntrustedTest():
+    '''
+    Decorator to skip execution of tests which are likely
+    to execute untrusted commands on the host, or commands
+    which process untrusted code, unless the
+    $QEMU_TEST_ALLOW_UNTRUSTED_CODE env var is set.
+    Example:
+
+      @skipUntrustedTest()
+    '''
     return skipUnless(os.getenv('QEMU_TEST_ALLOW_UNTRUSTED_CODE'),
                       'Test runs untrusted code / processes untrusted data')
 
-'''
-Decorator to skip execution of tests which need large
-data storage (over around 500MB-1GB mark) on the host,
-unless the $QEMU_TEST_ALLOW_LARGE_STORAGE environment
-variable is set
-
-Example:
-
-  @skipBigDataTest()
-'''
 def skipBigDataTest():
+    '''
+    Decorator to skip execution of tests which need large
+    data storage (over around 500MB-1GB mark) on the host,
+    unless the $QEMU_TEST_ALLOW_LARGE_STORAGE environment
+    variable is set
+
+    Example:
+
+      @skipBigDataTest()
+    '''
     return skipUnless(os.getenv('QEMU_TEST_ALLOW_LARGE_STORAGE'),
                       'Test requires large host storage space')
 
-'''
-Decorator to skip execution of tests which have a really long
-runtime (and might e.g. time out if QEMU has been compiled with
-debugging enabled) unless the $QEMU_TEST_ALLOW_SLOW
-environment variable is set
-
-Example:
-
-  @skipSlowTest()
-'''
 def skipSlowTest():
+    '''
+    Decorator to skip execution of tests which have a really long
+    runtime (and might e.g. time out if QEMU has been compiled with
+    debugging enabled) unless the $QEMU_TEST_ALLOW_SLOW
+    environment variable is set
+
+    Example:
+
+      @skipSlowTest()
+    '''
     return skipUnless(os.getenv('QEMU_TEST_ALLOW_SLOW'),
                       'Test has a very long runtime and might time out')
 
-'''
-Decorator to skip execution of a test if the list
-of python imports is not available.
-Example:
-
-  @skipIfMissingImports("numpy", "cv2")
-'''
 def skipIfMissingImports(*args):
+    '''
+    Decorator to skip execution of a test if the list
+    of python imports is not available.
+    Example:
+
+      @skipIfMissingImports("numpy", "cv2")
+    '''
     has_imports = True
     for impname in args:
         try:
@@ -151,15 +149,15 @@ def skipIfMissingImports(*args):
     return skipUnless(has_imports, 'required import(s) "%s" not installed' %
                                    ", ".join(args))
 
-'''
-Decorator to skip execution of a test if the system's
-locked memory limit is below the required threshold.
-Takes required locked memory threshold in kB.
-Example:
-
-  @skipLockedMemoryTest(2_097_152)
-'''
 def skipLockedMemoryTest(locked_memory):
+    '''
+    Decorator to skip execution of a test if the system's
+    locked memory limit is below the required threshold.
+    Takes required locked memory threshold in kB.
+    Example:
+
+      @skipLockedMemoryTest(2_097_152)
+    '''
     # get memlock hard limit in bytes
     _, ulimit_memory = resource.getrlimit(resource.RLIMIT_MEMLOCK)
 
diff --git a/tests/functional/qemu_test/linuxkernel.py b/tests/functional/qemu_test/linuxkernel.py
index c4767527da..eb10a81335 100644
--- a/tests/functional/qemu_test/linuxkernel.py
+++ b/tests/functional/qemu_test/linuxkernel.py
@@ -83,12 +83,12 @@ class LinuxKernelTest(QemuSystemTest):
         self.vm.set_console(console_index=console_index)
         self.vm.add_args('-kernel', kernel)
         if initrd:
-                self.vm.add_args('-initrd', initrd)
+            self.vm.add_args('-initrd', initrd)
         if dtb:
-                self.vm.add_args('-dtb', dtb)
+            self.vm.add_args('-dtb', dtb)
         self.vm.launch()
         if wait_for:
-                self.wait_for_console_pattern(wait_for)
+            self.wait_for_console_pattern(wait_for)
 
     def check_http_download(self, filename, hashsum, guestport=8080,
                             pythoncmd='python3 -m http.server'):
diff --git a/tests/functional/qemu_test/testcase.py b/tests/functional/qemu_test/testcase.py
index 2c0abde395..1d773dd697 100644
--- a/tests/functional/qemu_test/testcase.py
+++ b/tests/functional/qemu_test/testcase.py
@@ -217,7 +217,7 @@ class QemuBaseTest(unittest.TestCase):
         self._log_fh = logging.FileHandler(self.log_filename, mode='w')
         self._log_fh.setLevel(logging.DEBUG)
         fileFormatter = logging.Formatter(
-            '%(asctime)s - %(levelname)s: %(message)s')
+            '%(asctime)s - %(levelname)s: %(name)s.%(funcName)s %(message)s')
         self._log_fh.setFormatter(fileFormatter)
         self.log.addHandler(self._log_fh)
 
@@ -225,6 +225,9 @@ class QemuBaseTest(unittest.TestCase):
         self.machinelog = logging.getLogger('qemu.machine')
         self.machinelog.setLevel(logging.DEBUG)
         self.machinelog.addHandler(self._log_fh)
+        self.qmplog = logging.getLogger('qemu.qmp')
+        self.qmplog.setLevel(logging.DEBUG)
+        self.qmplog.addHandler(self._log_fh)
 
         if not self.assets_available():
             self.skipTest('One or more assets is not available')
@@ -233,8 +236,9 @@ class QemuBaseTest(unittest.TestCase):
         if "QEMU_TEST_KEEP_SCRATCH" not in os.environ:
             shutil.rmtree(self.workdir)
         if self.socketdir is not None:
-            shutil.rmtree(self.socketdir.name)
+            self.socketdir.cleanup()
             self.socketdir = None
+        self.qmplog.removeHandler(self._log_fh)
         self.machinelog.removeHandler(self._log_fh)
         self.log.removeHandler(self._log_fh)
         self._log_fh.close()
diff --git a/tests/functional/qemu_test/uncompress.py b/tests/functional/qemu_test/uncompress.py
index b7ef8f759b..5bbdf8fe32 100644
--- a/tests/functional/qemu_test/uncompress.py
+++ b/tests/functional/qemu_test/uncompress.py
@@ -58,20 +58,20 @@ def zstd_uncompress(zstd_path, output_path):
     os.chmod(output_path, stat.S_IRUSR | stat.S_IWUSR)
 
 
-'''
-@params compressed: filename, Asset, or file-like object to uncompress
-@params uncompressed: filename to uncompress into
-@params format: optional compression format (gzip, lzma)
-
-Uncompresses @compressed into @uncompressed
-
-If @format is None, heuristics will be applied to guess the format
-from the filename or Asset URL. @format must be non-None if @uncompressed
-is a file-like object.
-
-Returns the fully qualified path to the uncompessed file
-'''
 def uncompress(compressed, uncompressed, format=None):
+    '''
+    @params compressed: filename, Asset, or file-like object to uncompress
+    @params uncompressed: filename to uncompress into
+    @params format: optional compression format (gzip, lzma)
+
+    Uncompresses @compressed into @uncompressed
+
+    If @format is None, heuristics will be applied to guess the
+    format from the filename or Asset URL. @format must be non-None
+    if @uncompressed is a file-like object.
+
+    Returns the fully qualified path to the uncompessed file
+    '''
     if format is None:
         format = guess_uncompress_format(compressed)
 
@@ -84,19 +84,19 @@ def uncompress(compressed, uncompressed, format=None):
     else:
         raise Exception(f"Unknown compression format {format}")
 
-'''
-@params compressed: filename, Asset, or file-like object to guess
-
-Guess the format of @compressed, raising an exception if
-no format can be determined
-'''
 def guess_uncompress_format(compressed):
-    if type(compressed) == Asset:
+    '''
+    @params compressed: filename, Asset, or file-like object to guess
+
+    Guess the format of @compressed, raising an exception if
+    no format can be determined
+    '''
+    if isinstance(compressed, Asset):
         compressed = urlparse(compressed.url).path
-    elif type(compressed) != str:
+    elif not isinstance(compressed, str):
         raise Exception(f"Unable to guess compression cformat for {compressed}")
 
-    (name, ext) = os.path.splitext(compressed)
+    (_name, ext) = os.path.splitext(compressed)
     if ext == ".xz":
         return "xz"
     elif ext == ".gz":
diff --git a/tests/functional/qemu_test/utils.py b/tests/functional/qemu_test/utils.py
index e7c8de8165..826c267785 100644
--- a/tests/functional/qemu_test/utils.py
+++ b/tests/functional/qemu_test/utils.py
@@ -17,10 +17,10 @@ def get_usernet_hostfwd_port(vm):
     res = vm.cmd('human-monitor-command', command_line='info usernet')
     return get_info_usernet_hostfwd_port(res)
 
-"""
-Round up to next power of 2
-"""
 def pow2ceil(x):
+    """
+    Round up to next power of 2
+    """
     return 1 if x == 0 else 2**(x - 1).bit_length()
 
 def file_truncate(path, size):
@@ -28,12 +28,12 @@ def file_truncate(path, size):
         with open(path, 'ab+') as fd:
             fd.truncate(size)
 
-"""
-Expand file size to next power of 2
-"""
 def image_pow2ceil_expand(path):
-        size = os.path.getsize(path)
-        size_aligned = pow2ceil(size)
-        if size != size_aligned:
-            with open(path, 'ab+') as fd:
-                fd.truncate(size_aligned)
+    """
+    Expand file size to next power of 2
+    """
+    size = os.path.getsize(path)
+    size_aligned = pow2ceil(size)
+    if size != size_aligned:
+        with open(path, 'ab+') as fd:
+            fd.truncate(size_aligned)
diff --git a/tests/functional/rx/test_gdbsim.py b/tests/functional/rx/test_gdbsim.py
index 49245793e1..d31f9a42d6 100755
--- a/tests/functional/rx/test_gdbsim.py
+++ b/tests/functional/rx/test_gdbsim.py
@@ -17,9 +17,6 @@ from qemu_test import wait_for_console_pattern, skipFlakyTest
 
 class RxGdbSimMachine(QemuSystemTest):
 
-    timeout = 30
-    KERNEL_COMMON_COMMAND_LINE = 'printk.time=0 '
-
     ASSET_UBOOT = Asset(
         ('https://github.com/philmd/qemu-testing-blob/raw/rx-gdbsim/rx/gdbsim/'
          'u-boot.bin'),
@@ -47,7 +44,7 @@ class RxGdbSimMachine(QemuSystemTest):
         self.vm.launch()
         uboot_version = 'U-Boot 2016.05-rc3-23705-ga1ef3c71cb-dirty'
         wait_for_console_pattern(self, uboot_version)
-        gcc_version = 'rx-unknown-linux-gcc (GCC) 9.0.0 20181105 (experimental)'
+        #gcc_version = 'rx-unknown-linux-gcc (GCC) 9.0.0 20181105 (experimental)'
         # FIXME limit baudrate on chardev, else we type too fast
         #  https://gitlab.com/qemu-project/qemu/-/issues/2691
         #exec_command_and_wait_for_pattern(self, 'version', gcc_version)
@@ -63,7 +60,6 @@ class RxGdbSimMachine(QemuSystemTest):
         kernel_path = self.ASSET_KERNEL.fetch()
 
         self.vm.set_console()
-        kernel_command_line = self.KERNEL_COMMON_COMMAND_LINE + 'earlycon'
         self.vm.add_args('-kernel', kernel_path,
                          '-dtb', dtb_path,
                          '-no-reboot')
diff --git a/tests/functional/x86_64/test_acpi_bits.py b/tests/functional/x86_64/test_acpi_bits.py
index 9a2816533d..ec716d643b 100755
--- a/tests/functional/x86_64/test_acpi_bits.py
+++ b/tests/functional/x86_64/test_acpi_bits.py
@@ -57,6 +57,7 @@ class QEMUBitsMachine(QEMUMachine): # pylint: disable=too-few-public-methods
     """
     def __init__(self,
                  binary: str,
+                 *,
                  args: Sequence[str] = (),
                  wrapper: Sequence[str] = (),
                  name: Optional[str] = None,
@@ -225,7 +226,7 @@ class AcpiBitsTest(QemuSystemTest): #pylint: disable=too-many-instance-attribute
                                       stdout=subprocess.PIPE,
                                       stderr=subprocess.STDOUT,
                                       check=True)
-                self.log.info("grub-mkrescue output %s" % proc.stdout)
+                self.log.info("grub-mkrescue output %s", proc.stdout)
             else:
                 subprocess.check_call([mkrescue_script, '-o',
                                       iso_file, bits_dir],
@@ -287,9 +288,8 @@ class AcpiBitsTest(QemuSystemTest): #pylint: disable=too-many-instance-attribute
             except AssertionError as e:
                 self._print_log(log)
                 raise e
-            else:
-                if os.getenv('V') or os.getenv('BITS_DEBUG'):
-                    self._print_log(log)
+            if os.getenv('V') or os.getenv('BITS_DEBUG'):
+                self._print_log(log)
 
     def tearDown(self):
         """
diff --git a/tests/functional/x86_64/test_virtio_balloon.py b/tests/functional/x86_64/test_virtio_balloon.py
index 5877b6c408..7a579e0d69 100755
--- a/tests/functional/x86_64/test_virtio_balloon.py
+++ b/tests/functional/x86_64/test_virtio_balloon.py
@@ -66,7 +66,7 @@ class VirtioBalloonx86(QemuSystemTest):
         when = ret.get('last-update')
         assert when == 0
         stats = ret.get('stats')
-        for name, val in stats.items():
+        for _name, val in stats.items():
             assert val == UNSET_STATS_VALUE
 
     def assert_running_stats(self, then):
@@ -87,10 +87,10 @@ class VirtioBalloonx86(QemuSystemTest):
 
         now = time.time()
 
-        assert when > then and when < now
+        assert now > when > then
         stats = ret.get('stats')
         # Stat we expect this particular Kernel to have set
-        expectData = [
+        expect_data = [
             "stat-available-memory",
             "stat-disk-caches",
             "stat-free-memory",
@@ -103,7 +103,7 @@ class VirtioBalloonx86(QemuSystemTest):
             "stat-total-memory",
         ]
         for name, val in stats.items():
-            if name in expectData:
+            if name in expect_data:
                 assert val != UNSET_STATS_VALUE
             else:
                 assert val == UNSET_STATS_VALUE
diff --git a/tests/tcg/s390x/Makefile.softmmu-target b/tests/tcg/s390x/Makefile.softmmu-target
index 8cd4667c63..a4425d3184 100644
--- a/tests/tcg/s390x/Makefile.softmmu-target
+++ b/tests/tcg/s390x/Makefile.softmmu-target
@@ -28,6 +28,7 @@ ASM_TESTS =                                                                    \
     mc                                                                         \
     per                                                                        \
     precise-smc-softmmu                                                        \
+    sckc                                                                       \
     ssm-early                                                                  \
     stosm-early                                                                \
     stpq                                                                       \
diff --git a/tests/tcg/s390x/sckc.S b/tests/tcg/s390x/sckc.S
new file mode 100644
index 0000000000..ecd64a3059
--- /dev/null
+++ b/tests/tcg/s390x/sckc.S
@@ -0,0 +1,63 @@
+/*
+ * Test clock comparator.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+    .org 0x130
+ext_old_psw:
+    .org 0x1b0
+ext_new_psw:
+    .quad 0x180000000, _ext            /* 64-bit mode */
+    .org 0x1d0
+pgm_new_psw:
+    .quad 0x2000000000000,0            /* disabled wait */
+    .org 0x200                         /* lowcore padding */
+
+    .globl _start
+_start:
+    lpswe start31_psw
+_start31:
+    stctg %c0,%c0,c0
+    oi c0+6,8                          /* set clock-comparator subclass mask */
+    lctlg %c0,%c0,c0
+
+0:
+    brasl %r14,_f                      /* %r14's most significant bit is 1 */
+    jg 0b
+_f:
+    br %r14                            /* it must not end up in ext_old_psw */
+
+_ext:
+    stg %r0,ext_saved_r0
+
+    lg %r0,ext_counter
+    aghi %r0,1
+    stg %r0,ext_counter
+
+    cgfi %r0,0x1000
+    jnz 0f
+    lpswe success_psw
+0:
+
+    stck clock
+    lg %r0,clock
+    agfi %r0,0x40000                   /* 64us * 0x1000 =~ 0.25s */
+    stg %r0,clock
+    sckc clock
+
+    lg %r0,ext_saved_r0
+    lpswe ext_old_psw
+
+    .align 8
+start31_psw:
+    .quad 0x100000080000000,_start31   /* EX, 31-bit mode */
+success_psw:
+    .quad 0x2000000000000,0xfff        /* see is_special_wait_psw() */
+c0:
+    .skip 8
+clock:
+    .quad 0
+ext_counter:
+    .quad 0
+ext_saved_r0:
+    .skip 8