[PATCH v6 0/9] tests/functional: Adapt reverse_debugging to run w/o Avocado

[PATCH v6 0/9] tests/functional: Adapt reverse_debugging to run w/o Avocado

[Gustavo Romero]

The goal of this series is to remove Avocado as a dependency for running
the reverse_debugging functional test.

After several rounds of discussions about v1 and v2, and experiments
done by Daniel and Thomas (thanks for all the experiments and comments
so far), I've taken a new approach and moved away from using a runner
for GDB. The changes, I believe, are much simpler now.

This new series uses GDB's machine interface (MI) via the pygdbmi module
(thanks Manos and Peter for the inputs). pygdbmi provides a controller
to start GDB and communicate with it through MI, so there is no longer a
risk of version clashes between libpython in GDB and Python modules in
the pyvenv, as it could, in theory, happen when GDB executes the test
script via -x option.

Also, as Daniel pointed out, the overall test output is pretty bad and
currently does not allow one to easily follow the sequence of GDB
commands used in the test. I took this opportunity to improve the output
and it now prints the sequence in a format that can be copied and pasted
directly into GDB.

The TAP protocol is respected, and Meson correctly displays GDB's test
output in testlog-thorough.txt.

Because the pygdbmi "shim" is so thin, I had to write a trivial GDB
class around it to easily capture and print the payloads returned by its
write() method. The GDB class allows clean, single-line commands to be
used in the tests through method chaining, making them easier to follow,
for example:

pc = gdb.cli("print $pc").get_add()

The test is kept “skipped” for aarch64, ppc64, and x86_64, so it is
necessary to set QEMU_TEST_FLAKY_TESTS=1 in the test environment to
effectively run the test on these archs.

On aarch64, the test is flaky, but there is a fix that I’ve tested while
writing this series [0] that resolves it. On ppc64 and x86_64, the test
always fails: on ppc64, GDB gets a bogus PC, and on x86_64, the last
part of the test (reverse-continue) does not hit the last executed PC
(as it should happen) but instead jumps to the beginning of the code
(first PC in forward order).

Thus, to effectively run the reverse_debugging test on aarch64:

$ export QEMU_TEST_FLAKY_TESTS=1
$ make check-functional

or:
$ make check-functional-aarch64

or even, to run only the reverse_debug test after 'make check-functional':
$ ./pyvenv/bin/meson test --verbose --no-rebuild -t 1 --setup thorough --suite func-thorough func-aarch64-reverse_debug


Cheers,
Gustavo

v1:
https://patchew.org/QEMU/20250819143916.4138035-1-gustavo.romero@linaro.org/

v2:
https://patchew.org/QEMU/20250904154640.52687-1-gustavo.romero@linaro.org/

v3:
https://patchew.org/QEMU/20250922054351.14289-1-gustavo.romero@linaro.org/

v4:
https://patchew.org/QEMU/20250926051542.104432-1-gustavo.romero@linaro.org/

v5:
https://patchew.org/QEMU/20251002020432.54443-1-gustavo.romero@linaro.org/

v6:
- Fixed skipping test when no GDB is installed in the test environment


Daniel P. Berrangé (2):
  tests/functional: replace avocado process with subprocess
  tests/functional: drop datadrainer class in reverse debugging

Gustavo Romero (7):
  tests/functional: Re-activate the check-venv target
  python: Install pygdbmi in meson's venv
  tests/functional: Provide GDB to the functional tests
  tests/functional: Add GDB class
  tests/functional: Add decorator to skip test on missing env vars
  tests/functional: Adapt reverse_debugging to run w/o Avocado
  tests/functional: Adapt arches to reverse_debugging w/o Avocado

 configure                                     |   2 +
 meson_options.txt                             |   2 +
 pythondeps.toml                               |   1 +
 scripts/meson-buildoptions.sh                 |   2 +
 tests/Makefile.include                        |   4 +-
 .../functional/aarch64/test_reverse_debug.py  |  11 +-
 tests/functional/meson.build                  |   6 +
 tests/functional/ppc64/test_reverse_debug.py  |  15 +-
 tests/functional/qemu_test/__init__.py        |   4 +-
 tests/functional/qemu_test/decorators.py      |  18 +++
 tests/functional/qemu_test/gdb.py             |  88 ++++++++++
 tests/functional/reverse_debugging.py         | 151 +++++++++---------
 tests/functional/x86_64/test_reverse_debug.py |  15 +-
 13 files changed, 218 insertions(+), 101 deletions(-)
 create mode 100644 tests/functional/qemu_test/gdb.py

-- 
2.34.1

[PATCH v6 1/9] tests/functional: Re-activate the check-venv target

[Gustavo Romero]

Add check-venv target as a dependency for the functional tests. This
causes Python modules listed in pythondeps.toml, under the testdeps
group, to be installed when 'make check-functional{-<ARCH>}' is executed
to prepare and run the functional tests.

Suggested-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
---
 tests/Makefile.include | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/Makefile.include b/tests/Makefile.include
index 62a4fc8ed3..e47ef4d45c 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -105,11 +105,11 @@ check-venv: $(TESTS_VENV_TOKEN)
 
 FUNCTIONAL_TARGETS=$(patsubst %-softmmu,check-functional-%, $(filter %-softmmu,$(TARGETS)))
 .PHONY: $(FUNCTIONAL_TARGETS)
-$(FUNCTIONAL_TARGETS):
+$(FUNCTIONAL_TARGETS): check-venv
 	@$(MAKE) SPEED=thorough $(subst -functional,-func,$@)
 
 .PHONY: check-functional
-check-functional:
+check-functional: check-venv
 	@$(NINJA) precache-functional
 	@QEMU_TEST_NO_DOWNLOAD=1 $(MAKE) SPEED=thorough check-func check-func-quick
 
-- 
2.34.1

[PATCH v6 2/9] python: Install pygdbmi in meson's venv

[Gustavo Romero]

The upcoming changes in the reverse_debugging functional test to remove
Avocado as a dependency will require pygdbmi for interacting with GDB,
so install it in meson's venv (located in the build dir's pyvenv/).

Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
---
 pythondeps.toml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pythondeps.toml b/pythondeps.toml
index 16fb2a989c..98e99e7900 100644
--- a/pythondeps.toml
+++ b/pythondeps.toml
@@ -33,3 +33,4 @@ sphinx_rtd_theme = { accepted = ">=0.5", installed = "1.2.2" }
 
 [testdeps]
 qemu.qmp = { accepted = ">=0.0.3", installed = "0.0.3" }
+pygdbmi = { accepted = ">=0.11.0.0", installed = "0.11.0.0" }
-- 
2.34.1

[PATCH v6 3/9] tests/functional: Provide GDB to the functional tests

[Gustavo Romero]

The probe of GDB is done in 'configure' and the full path is passed to
meson.build via the -Dgdb=option.

Meson then can pass the location of GDB to the functional tests via an
environment variable: QEMU_TEST_GDB.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
---
 configure                     | 2 ++
 meson_options.txt             | 2 ++
 scripts/meson-buildoptions.sh | 2 ++
 tests/functional/meson.build  | 6 ++++++
 4 files changed, 12 insertions(+)

diff --git a/configure b/configure
index 78445cbb4b..21d1679f58 100755
--- a/configure
+++ b/configure
@@ -2003,6 +2003,8 @@ if test "$skip_meson" = no; then
   test -n "${LIB_FUZZING_ENGINE+xxx}" && meson_option_add "-Dfuzzing_engine=$LIB_FUZZING_ENGINE"
   test "$plugins" = yes && meson_option_add "-Dplugins=true"
   test "$tcg" != enabled && meson_option_add "-Dtcg=$tcg"
+  test -n "$gdb_bin" && meson_option_add "-Dgdb=$gdb_bin"
+
   run_meson() {
     NINJA=$ninja $meson setup "$@" "$PWD" "$source_path"
   }
diff --git a/meson_options.txt b/meson_options.txt
index fff1521e58..5bb41bcbc4 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -36,6 +36,8 @@ option('trace_file', type: 'string', value: 'trace',
 option('coroutine_backend', type: 'combo',
        choices: ['ucontext', 'sigaltstack', 'windows', 'wasm', 'auto'],
        value: 'auto', description: 'coroutine backend to use')
+option('gdb', type: 'string', value: '',
+       description: 'Path to GDB')
 
 # Everything else can be set via --enable/--disable-* option
 # on the configure script command line.  After adding an option
diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
index 0ebe6bc52a..f4bd21220e 100644
--- a/scripts/meson-buildoptions.sh
+++ b/scripts/meson-buildoptions.sh
@@ -58,6 +58,7 @@ meson_options_help() {
   printf "%s\n" '  --enable-ubsan           enable undefined behaviour sanitizer'
   printf "%s\n" '  --firmwarepath=VALUES    search PATH for firmware files [share/qemu-'
   printf "%s\n" '                           firmware]'
+  printf "%s\n" '  --gdb=VALUE              Path to GDB'
   printf "%s\n" '  --iasl=VALUE             Path to ACPI disassembler'
   printf "%s\n" '  --includedir=VALUE       Header file directory [include]'
   printf "%s\n" '  --interp-prefix=VALUE    where to find shared libraries etc., use %M for'
@@ -323,6 +324,7 @@ _meson_option_parse() {
     --disable-fuzzing) printf "%s" -Dfuzzing=false ;;
     --enable-gcrypt) printf "%s" -Dgcrypt=enabled ;;
     --disable-gcrypt) printf "%s" -Dgcrypt=disabled ;;
+    --gdb=*) quote_sh "-Dgdb=$2" ;;
     --enable-gettext) printf "%s" -Dgettext=enabled ;;
     --disable-gettext) printf "%s" -Dgettext=disabled ;;
     --enable-gio) printf "%s" -Dgio=enabled ;;
diff --git a/tests/functional/meson.build b/tests/functional/meson.build
index 2a0c5aa141..725630d308 100644
--- a/tests/functional/meson.build
+++ b/tests/functional/meson.build
@@ -77,6 +77,12 @@ foreach speed : ['quick', 'thorough']
     test_env.set('PYTHONPATH', meson.project_source_root() / 'python:' +
                                meson.current_source_dir())
 
+    # Define the GDB environment variable if gdb is available.
+    gdb = get_option('gdb')
+    if gdb != ''
+      test_env.set('QEMU_TEST_GDB', gdb)
+    endif
+
     foreach test : target_tests
       testname = '@0@-@1@'.format(target_base, test)
       if fs.exists('generic' / 'test_' + test + '.py')
-- 
2.34.1

[PATCH v6 4/9] tests/functional: Add GDB class

[Gustavo Romero]

Add GDB class, which provides methods to run GDB commands and capture
their output. The GDB class is a wrapper around the pygdbmi module and
interacts with GDB via GDB's machine interface (MI).

Acked-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
---
 tests/functional/qemu_test/__init__.py |  1 +
 tests/functional/qemu_test/gdb.py      | 88 ++++++++++++++++++++++++++
 2 files changed, 89 insertions(+)
 create mode 100644 tests/functional/qemu_test/gdb.py

diff --git a/tests/functional/qemu_test/__init__.py b/tests/functional/qemu_test/__init__.py
index 6e666a059f..60d19891bf 100644
--- a/tests/functional/qemu_test/__init__.py
+++ b/tests/functional/qemu_test/__init__.py
@@ -18,3 +18,4 @@
     skipIfMissingImports, skipIfOperatingSystem, skipLockedMemoryTest
 from .archive import archive_extract
 from .uncompress import uncompress
+from .gdb import GDB
diff --git a/tests/functional/qemu_test/gdb.py b/tests/functional/qemu_test/gdb.py
new file mode 100644
index 0000000000..05e4c29c2a
--- /dev/null
+++ b/tests/functional/qemu_test/gdb.py
@@ -0,0 +1,88 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# A simple interface module built around pygdbmi for handling GDB commands.
+#
+# Copyright (c) 2025 Linaro Limited
+#
+# Author:
+#  Gustavo Romero <gustavo.romero@linaro.org>
+#
+# 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 re
+
+
+class GDB:
+    """Provides methods to run and capture GDB command output."""
+
+
+    def __init__(self, gdb_path, echo=True, suffix='# ', prompt="$ "):
+        from pygdbmi.gdbcontroller import GdbController
+        from pygdbmi.constants import GdbTimeoutError
+        type(self).TimeoutError = GdbTimeoutError
+
+        gdb_cmd = [gdb_path, "-q", "--interpreter=mi2"]
+        self.gdbmi = GdbController(gdb_cmd)
+        self.echo = echo
+        self.suffix = suffix
+        self.prompt = prompt
+        self.response = None
+        self.cmd_output = None
+
+
+    def get_payload(self, response, kind):
+        output = []
+        for o in response:
+            # Unpack payloads of the same type.
+            _type, _, payload, *_ = o.values()
+            if _type == kind:
+                output += [payload]
+
+        # Some output lines do not end with \n but begin with it,
+        # so remove the leading \n and merge them with the next line
+        # that ends with \n.
+        lines = [line.lstrip('\n') for line in output]
+        lines = "".join(lines)
+        lines = lines.splitlines(keepends=True)
+
+        return lines
+
+
+    def cli(self, cmd, timeout=32.0):
+        self.response = self.gdbmi.write(cmd, timeout_sec=timeout)
+        self.cmd_output = self.get_payload(self.response, kind="console")
+        if self.echo:
+            print(self.suffix + self.prompt + cmd)
+
+            if len(self.cmd_output) > 0:
+                cmd_output = self.suffix.join(self.cmd_output)
+                print(self.suffix + cmd_output, end="")
+
+        return self
+
+
+    def get_addr(self):
+        address_pattern = r"0x[0-9A-Fa-f]+"
+        cmd_output = "".join(self.cmd_output) # Concat output lines.
+
+        match = re.search(address_pattern, cmd_output)
+
+        return int(match[0], 16) if match else None
+
+
+    def get_log(self):
+        r = self.get_payload(self.response, kind="log")
+        r = "".join(r)
+
+        return r
+
+
+    def get_console(self):
+        r = "".join(self.cmd_output)
+
+        return r
+
+
+    def exit(self):
+        self.gdbmi.exit()
-- 
2.34.1

[PATCH v6 5/9] tests/functional: replace avocado process with subprocess

[Gustavo Romero]

From: Daniel P. Berrangé <berrange@redhat.com>

The standard python subprocess.check_call method is better than
avocado.utils.process as it doesn't require stuffing all args
into a single string.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
 tests/functional/reverse_debugging.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/tests/functional/reverse_debugging.py b/tests/functional/reverse_debugging.py
index f9a1d395f1..a7ff47cb90 100644
--- a/tests/functional/reverse_debugging.py
+++ b/tests/functional/reverse_debugging.py
@@ -11,6 +11,7 @@
 # later.  See the COPYING file in the top-level directory.
 import os
 import logging
+from subprocess import check_output
 
 from qemu_test import LinuxKernelTest, get_qemu_img
 from qemu_test.ports import Ports
@@ -100,7 +101,6 @@ def vm_get_icount(vm):
 
     def reverse_debugging(self, shift=7, args=None):
         from avocado.utils import gdb
-        from avocado.utils import process
 
         logger = logging.getLogger('replay')
 
@@ -111,8 +111,9 @@ def reverse_debugging(self, shift=7, args=None):
         if qemu_img is None:
             self.skipTest('Could not find "qemu-img", which is required to '
                           'create the temporary qcow2 image')
-        cmd = '%s create -f qcow2 %s 128M' % (qemu_img, image_path)
-        process.run(cmd)
+        out = check_output([qemu_img, 'create', '-f', 'qcow2', image_path, '128M'],
+                           encoding='utf8')
+        logger.info("qemu-img: %s" % out)
 
         replay_path = os.path.join(self.workdir, 'replay.bin')
 
-- 
2.34.1

[PATCH v6 6/9] tests/functional: drop datadrainer class in reverse debugging

[Gustavo Romero]

From: Daniel P. Berrangé <berrange@redhat.com>

The reverse debugging test uses the avocado datadrainer class to
create a background thread that reads from the console socket and
dumps it via python logger.

Most tests log console output as a side effect of doing calls
to match strings, but this test never tries to match anything.

This isn't critical, so just drop the functionality.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
 tests/functional/reverse_debugging.py | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/tests/functional/reverse_debugging.py b/tests/functional/reverse_debugging.py
index a7ff47cb90..7fd8c7607f 100644
--- a/tests/functional/reverse_debugging.py
+++ b/tests/functional/reverse_debugging.py
@@ -34,8 +34,6 @@ class ReverseDebugging(LinuxKernelTest):
     endian_is_le = True
 
     def run_vm(self, record, shift, args, replay_path, image_path, port):
-        from avocado.utils import datadrainer
-
         logger = logging.getLogger('replay')
         vm = self.get_vm(name='record' if record else 'replay')
         vm.set_console()
@@ -53,10 +51,6 @@ def run_vm(self, record, shift, args, replay_path, image_path, port):
         if args:
             vm.add_args(*args)
         vm.launch()
-        console_drainer = datadrainer.LineLogger(vm.console_socket.fileno(),
-                                    logger=self.log.getChild('console'),
-                                    stop_check=(lambda : not vm.is_running()))
-        console_drainer.start()
         return vm
 
     @staticmethod
-- 
2.34.1

[PATCH v6 7/9] tests/functional: Add decorator to skip test on missing env vars

[Gustavo Romero]

Add a decorator to skip tests on missing env variable(s). Multiple
variable names can be provided and if one or more of them are not set in
the test environment the test is skipped and the missing vars are
printed out.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
---
 tests/functional/qemu_test/__init__.py   |  3 ++-
 tests/functional/qemu_test/decorators.py | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/tests/functional/qemu_test/__init__.py b/tests/functional/qemu_test/__init__.py
index 60d19891bf..320193591b 100644
--- a/tests/functional/qemu_test/__init__.py
+++ b/tests/functional/qemu_test/__init__.py
@@ -15,7 +15,8 @@
 from .linuxkernel import LinuxKernelTest
 from .decorators import skipIfMissingCommands, skipIfNotMachine, \
     skipFlakyTest, skipUntrustedTest, skipBigDataTest, skipSlowTest, \
-    skipIfMissingImports, skipIfOperatingSystem, skipLockedMemoryTest
+    skipIfMissingImports, skipIfOperatingSystem, skipLockedMemoryTest, \
+    skipIfMissingEnv
 from .archive import archive_extract
 from .uncompress import uncompress
 from .gdb import GDB
diff --git a/tests/functional/qemu_test/decorators.py b/tests/functional/qemu_test/decorators.py
index c0d1567b14..b239295804 100644
--- a/tests/functional/qemu_test/decorators.py
+++ b/tests/functional/qemu_test/decorators.py
@@ -11,6 +11,24 @@
 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_):
+    missing_vars = []
+    for var in vars_:
+        if os.getenv(var) == None:
+            missing_vars.append(var)
+
+    has_vars = True if len(missing_vars) == 0 else False
+
+    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:
-- 
2.34.1

[PATCH v6 8/9] tests/functional: Adapt reverse_debugging to run w/o Avocado

[Gustavo Romero]

This commit removes Avocado as a dependency for running the
reverse_debugging test.

The main benefit, beyond eliminating an extra dependency, is that there
is no longer any need to handle GDB packets manually. This removes the
need for ad-hoc functions dealing with endianness and arch-specific
register numbers, making the test easier to read. The timeout variable
is also removed, since Meson now manages timeouts automatically.

reverse_debugging now uses the pygdbmi module to interact with GDB, if
it's available in the test environment, otherwise the test is skipped.
GDB is detect via the QEMU_TEST_GDB env. variable.

This commit also significantly improves the output for the test and
now prints all the GDB commands used in sequence. It also adds
some clarifications to existing comments, for example, clarifying that
once the replay-break is reached, a SIGINT is captured in GDB.

reverse_debugging is kept "skipped" for aarch64, ppc64, and x86_64, so
won't run unless QEMU_TEST_FLAKY_TESTS=1 is set in the test environment,
before running 'make check-functional' or 'meson test [...]'.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
---
 tests/functional/reverse_debugging.py | 138 ++++++++++++++------------
 1 file changed, 74 insertions(+), 64 deletions(-)

diff --git a/tests/functional/reverse_debugging.py b/tests/functional/reverse_debugging.py
index 7fd8c7607f..2a2e51b912 100644
--- a/tests/functional/reverse_debugging.py
+++ b/tests/functional/reverse_debugging.py
@@ -1,19 +1,22 @@
-# Reverse debugging test
-#
 # SPDX-License-Identifier: GPL-2.0-or-later
 #
+# Reverse debugging test
+#
 # Copyright (c) 2020 ISP RAS
+# Copyright (c) 2025 Linaro Limited
 #
 # Author:
 #  Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
+#  Gustavo Romero <gustavo.romero@linaro.org> (Run without Avocado)
 #
 # 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 os
 from subprocess import check_output
 
-from qemu_test import LinuxKernelTest, get_qemu_img
+from qemu_test import LinuxKernelTest, get_qemu_img, GDB, skipIfMissingEnv, skipIfMissingImports
 from qemu_test.ports import Ports
 
 
@@ -29,9 +32,7 @@ class ReverseDebugging(LinuxKernelTest):
     that the execution is stopped at the last of them.
     """
 
-    timeout = 10
     STEPS = 10
-    endian_is_le = True
 
     def run_vm(self, record, shift, args, replay_path, image_path, port):
         logger = logging.getLogger('replay')
@@ -54,47 +55,17 @@ def run_vm(self, record, shift, args, replay_path, image_path, port):
         return vm
 
     @staticmethod
-    def get_reg_le(g, reg):
-        res = g.cmd(b'p%x' % reg)
-        num = 0
-        for i in range(len(res))[-2::-2]:
-            num = 0x100 * num + int(res[i:i + 2], 16)
-        return num
-
-    @staticmethod
-    def get_reg_be(g, reg):
-        res = g.cmd(b'p%x' % reg)
-        return int(res, 16)
-
-    def get_reg(self, g, reg):
-        # value may be encoded in BE or LE order
-        if self.endian_is_le:
-            return self.get_reg_le(g, reg)
-        else:
-            return self.get_reg_be(g, reg)
-
-    def get_pc(self, g):
-        return self.get_reg(g, self.REG_PC)
-
-    def check_pc(self, g, addr):
-        pc = self.get_pc(g)
-        if pc != addr:
-            self.fail('Invalid PC (read %x instead of %x)' % (pc, addr))
-
-    @staticmethod
-    def gdb_step(g):
-        g.cmd(b's', b'T05thread:01;')
-
-    @staticmethod
-    def gdb_bstep(g):
-        g.cmd(b'bs', b'T05thread:01;')
+    def get_pc(gdb: GDB):
+        return gdb.cli("print $pc").get_addr()
 
     @staticmethod
     def vm_get_icount(vm):
         return vm.qmp('query-replay')['return']['icount']
 
-    def reverse_debugging(self, shift=7, args=None):
-        from avocado.utils import gdb
+    @skipIfMissingImports("pygdbmi") # Required by GDB class
+    @skipIfMissingEnv("QEMU_TEST_GDB")
+    def reverse_debugging(self, gdb_arch, shift=7, args=None):
+        from qemu_test import GDB
 
         logger = logging.getLogger('replay')
 
@@ -124,68 +95,107 @@ def reverse_debugging(self, shift=7, args=None):
         with Ports() as ports:
             port = ports.find_free_port()
             vm = self.run_vm(False, shift, args, replay_path, image_path, port)
-        logger.info('connecting to gdbstub')
-        g = gdb.GDBRemote('127.0.0.1', port, False, False)
-        g.connect()
-        r = g.cmd(b'qSupported')
-        if b'qXfer:features:read+' in r:
-            g.cmd(b'qXfer:features:read:target.xml:0,ffb')
-        if b'ReverseStep+' not in r:
+
+        try:
+            logger.info('Connecting to gdbstub...')
+            self.reverse_debugging_run(vm, port, gdb_arch, last_icount)
+            logger.info('Test passed.')
+        except GDB.TimeoutError:
+            # Convert a GDB timeout exception into a unittest failure exception.
+            raise self.failureException("Timeout while connecting to or "
+                                        "communicating with gdbstub...") from None
+        except Exception:
+            # Re-throw exceptions from unittest, like the ones caused by fail(),
+            # skipTest(), etc.
+            raise
+
+    def reverse_debugging_run(self, vm, port, gdb_arch, last_icount):
+        logger = logging.getLogger('replay')
+
+        gdb_cmd = os.getenv('QEMU_TEST_GDB')
+        gdb = GDB(gdb_cmd)
+
+        r = gdb.cli("set architecture").get_log()
+        if gdb_arch not in r:
+            self.skipTest(f"GDB does not support arch '{gdb_arch}'")
+
+        gdb.cli("set debug remote 1")
+
+        c = gdb.cli(f"target remote localhost:{port}").get_console()
+        if not f"Remote debugging using localhost:{port}" in c:
+            self.fail("Could not connect to gdbstub!")
+
+        # Remote debug messages are in 'log' payloads.
+        r = gdb.get_log()
+        if 'ReverseStep+' not in r:
             self.fail('Reverse step is not supported by QEMU')
-        if b'ReverseContinue+' not in r:
+        if 'ReverseContinue+' not in r:
             self.fail('Reverse continue is not supported by QEMU')
 
+        gdb.cli("set debug remote 0")
+
         logger.info('stepping forward')
         steps = []
         # record first instruction addresses
         for _ in range(self.STEPS):
-            pc = self.get_pc(g)
+            pc = self.get_pc(gdb)
             logger.info('saving position %x' % pc)
             steps.append(pc)
-            self.gdb_step(g)
+            gdb.cli("stepi")
 
         # visit the recorded instruction in reverse order
         logger.info('stepping backward')
         for addr in steps[::-1]:
-            self.gdb_bstep(g)
-            self.check_pc(g, addr)
             logger.info('found position %x' % addr)
+            gdb.cli("reverse-stepi")
+            pc = self.get_pc(gdb)
+            if pc != addr:
+                logger.info('Invalid PC (read %x instead of %x)' % (pc, addr))
+                self.fail('Reverse stepping failed!')
 
         # visit the recorded instruction in forward order
         logger.info('stepping forward')
         for addr in steps:
-            self.check_pc(g, addr)
-            self.gdb_step(g)
             logger.info('found position %x' % addr)
+            pc = self.get_pc(gdb)
+            if pc != addr:
+                logger.info('Invalid PC (read %x instead of %x)' % (pc, addr))
+                self.fail('Forward stepping failed!')
+            gdb.cli("stepi")
 
         # set breakpoints for the instructions just stepped over
         logger.info('setting breakpoints')
         for addr in steps:
-            # hardware breakpoint at addr with len=1
-            g.cmd(b'Z1,%x,1' % addr, b'OK')
+            gdb.cli(f"break *{hex(addr)}")
 
         # this may hit a breakpoint if first instructions are executed
         # again
         logger.info('continuing execution')
         vm.qmp('replay-break', icount=last_icount - 1)
         # continue - will return after pausing
-        # This could stop at the end and get a T02 return, or by
-        # re-executing one of the breakpoints and get a T05 return.
-        g.cmd(b'c')
+        # This can stop at the end of the replay-break and gdb gets a SIGINT,
+        # or by re-executing one of the breakpoints and gdb stops at a
+        # breakpoint.
+        gdb.cli("continue")
+
         if self.vm_get_icount(vm) == last_icount - 1:
             logger.info('reached the end (icount %s)' % (last_icount - 1))
         else:
             logger.info('hit a breakpoint again at %x (icount %s)' %
-                        (self.get_pc(g), self.vm_get_icount(vm)))
+                        (self.get_pc(gdb), self.vm_get_icount(vm)))
 
         logger.info('running reverse continue to reach %x' % steps[-1])
         # reverse continue - will return after stopping at the breakpoint
-        g.cmd(b'bc', b'T05thread:01;')
+        gdb.cli("reverse-continue")
 
         # assume that none of the first instructions is executed again
         # breaking the order of the breakpoints
-        self.check_pc(g, steps[-1])
+        pc = self.get_pc(gdb)
+        if pc != steps[-1]:
+            self.fail("'reverse-continue' did not hit the first PC in reverse order!")
+
         logger.info('successfully reached %x' % steps[-1])
 
         logger.info('exiting gdb and qemu')
+        gdb.exit()
         vm.shutdown()
-- 
2.34.1

[PATCH v6 9/9] tests/functional: Adapt arches to reverse_debugging w/o Avocado

[Gustavo Romero]

reverse_debugging no longer depends on Avocado, so remove the import
checks for Avocado, the per-arch endianness tweaks, and the per-arch
register settings. All of these are now handled in the ReverseDebugging
class, automatically.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
---
 tests/functional/aarch64/test_reverse_debug.py | 11 +++++------
 tests/functional/ppc64/test_reverse_debug.py   | 15 ++++++---------
 tests/functional/x86_64/test_reverse_debug.py  | 15 +++++----------
 3 files changed, 16 insertions(+), 25 deletions(-)

diff --git a/tests/functional/aarch64/test_reverse_debug.py b/tests/functional/aarch64/test_reverse_debug.py
index 8bc91ccfde..906f10aec5 100755
--- a/tests/functional/aarch64/test_reverse_debug.py
+++ b/tests/functional/aarch64/test_reverse_debug.py
@@ -2,25 +2,24 @@
 #
 # SPDX-License-Identifier: GPL-2.0-or-later
 #
-# Reverse debugging test
+# Reverse debugging test for aarch64
 #
 # Copyright (c) 2020 ISP RAS
+# Copyright (c) 2025 Linaro Limited
 #
 # Author:
 #  Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
+#  Gustavo Romero <gustavo.romero@linaro.org> (Run without Avocado)
 #
 # This work is licensed under the terms of the GNU GPL, version 2 or
 # later.  See the COPYING file in the top-level directory.
 
-from qemu_test import Asset, skipIfMissingImports, skipFlakyTest
+from qemu_test import Asset, skipFlakyTest
 from reverse_debugging import ReverseDebugging
 
 
-@skipIfMissingImports('avocado.utils')
 class ReverseDebugging_AArch64(ReverseDebugging):
 
-    REG_PC = 32
-
     ASSET_KERNEL = Asset(
         ('https://archives.fedoraproject.org/pub/archive/fedora/linux/'
          'releases/29/Everything/aarch64/os/images/pxeboot/vmlinuz'),
@@ -31,7 +30,7 @@ def test_aarch64_virt(self):
         self.set_machine('virt')
         self.cpu = 'cortex-a53'
         kernel_path = self.ASSET_KERNEL.fetch()
-        self.reverse_debugging(args=('-kernel', kernel_path))
+        self.reverse_debugging(gdb_arch='aarch64', args=('-kernel', kernel_path))
 
 
 if __name__ == '__main__':
diff --git a/tests/functional/ppc64/test_reverse_debug.py b/tests/functional/ppc64/test_reverse_debug.py
index 5931adef5a..69551fb84d 100755
--- a/tests/functional/ppc64/test_reverse_debug.py
+++ b/tests/functional/ppc64/test_reverse_debug.py
@@ -2,39 +2,36 @@
 #
 # SPDX-License-Identifier: GPL-2.0-or-later
 #
-# Reverse debugging test
+# Reverse debugging test for ppc64
 #
 # Copyright (c) 2020 ISP RAS
+# Copyright (c) 2025 Linaro Limited
 #
 # Author:
 #  Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
+#  Gustavo Romero <gustavo.romero@linaro.org> (Run without Avocado)
 #
 # This work is licensed under the terms of the GNU GPL, version 2 or
 # later.  See the COPYING file in the top-level directory.
 
-from qemu_test import skipIfMissingImports, skipFlakyTest
+from qemu_test import skipFlakyTest
 from reverse_debugging import ReverseDebugging
 
 
-@skipIfMissingImports('avocado.utils')
 class ReverseDebugging_ppc64(ReverseDebugging):
 
-    REG_PC = 0x40
-
     @skipFlakyTest("https://gitlab.com/qemu-project/qemu/-/issues/1992")
     def test_ppc64_pseries(self):
         self.set_machine('pseries')
         # SLOF branches back to its entry point, which causes this test
         # to take the 'hit a breakpoint again' path. That's not a problem,
         # just slightly different than the other machines.
-        self.endian_is_le = False
-        self.reverse_debugging()
+        self.reverse_debugging(gdb_arch='powerpc:common64')
 
     @skipFlakyTest("https://gitlab.com/qemu-project/qemu/-/issues/1992")
     def test_ppc64_powernv(self):
         self.set_machine('powernv')
-        self.endian_is_le = False
-        self.reverse_debugging()
+        self.reverse_debugging(gdb_arch='powerpc:common64')
 
 
 if __name__ == '__main__':
diff --git a/tests/functional/x86_64/test_reverse_debug.py b/tests/functional/x86_64/test_reverse_debug.py
index d713e91e14..2b31ae8724 100755
--- a/tests/functional/x86_64/test_reverse_debug.py
+++ b/tests/functional/x86_64/test_reverse_debug.py
@@ -2,34 +2,29 @@
 #
 # SPDX-License-Identifier: GPL-2.0-or-later
 #
-# Reverse debugging test
+# Reverse debugging test for x86_64
 #
 # Copyright (c) 2020 ISP RAS
+# Copyright (c) 2025 Linaro Limited
 #
 # Author:
 #  Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
+#  Gustavo Romero <gustavo.romero@linaro.org> (Run without Avocado)
 #
 # This work is licensed under the terms of the GNU GPL, version 2 or
 # later.  See the COPYING file in the top-level directory.
 
-from qemu_test import skipIfMissingImports, skipFlakyTest
+from qemu_test import skipFlakyTest
 from reverse_debugging import ReverseDebugging
 
 
-@skipIfMissingImports('avocado.utils')
 class ReverseDebugging_X86_64(ReverseDebugging):
 
-    REG_PC = 0x10
-    REG_CS = 0x12
-    def get_pc(self, g):
-        return self.get_reg_le(g, self.REG_PC) \
-            + self.get_reg_le(g, self.REG_CS) * 0x10
-
     @skipFlakyTest("https://gitlab.com/qemu-project/qemu/-/issues/2922")
     def test_x86_64_pc(self):
         self.set_machine('pc')
         # start with BIOS only
-        self.reverse_debugging()
+        self.reverse_debugging(gdb_arch='x86-64')
 
 
 if __name__ == '__main__':
-- 
2.34.1

Re: [PATCH v6 4/9] tests/functional: Add GDB class

[Thomas Huth]

On 03/10/2025 16.18, Gustavo Romero wrote:
> Add GDB class, which provides methods to run GDB commands and capture
> their output. The GDB class is a wrapper around the pygdbmi module and
> interacts with GDB via GDB's machine interface (MI).
> 
> Acked-by: Thomas Huth <thuth@redhat.com>
> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
> Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
> ---
>   tests/functional/qemu_test/__init__.py |  1 +
>   tests/functional/qemu_test/gdb.py      | 88 ++++++++++++++++++++++++++
>   2 files changed, 89 insertions(+)
>   create mode 100644 tests/functional/qemu_test/gdb.py
> 
> diff --git a/tests/functional/qemu_test/__init__.py b/tests/functional/qemu_test/__init__.py
> index 6e666a059f..60d19891bf 100644
> --- a/tests/functional/qemu_test/__init__.py
> +++ b/tests/functional/qemu_test/__init__.py
> @@ -18,3 +18,4 @@
>       skipIfMissingImports, skipIfOperatingSystem, skipLockedMemoryTest
>   from .archive import archive_extract
>   from .uncompress import uncompress
> +from .gdb import GDB
> diff --git a/tests/functional/qemu_test/gdb.py b/tests/functional/qemu_test/gdb.py
> new file mode 100644
> index 0000000000..05e4c29c2a
> --- /dev/null
> +++ b/tests/functional/qemu_test/gdb.py
> @@ -0,0 +1,88 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +#
> +# A simple interface module built around pygdbmi for handling GDB commands.
> +#
> +# Copyright (c) 2025 Linaro Limited
> +#
> +# Author:
> +#  Gustavo Romero <gustavo.romero@linaro.org>
> +#
> +# This work is licensed under the terms of the GNU GPL, version 2 or
> +# later.  See the COPYING file in the top-level directory.

  Hi,

just as a reminder, this still needs the change requested by Daniel:

https://lore.kernel.org/qemu-devel/aN56GkbIFxs5IDRR@redhat.com/

  Thomas

Re: [PATCH v6 0/9] tests/functional: Adapt reverse_debugging to run w/o Avocado

[Thomas Huth]

On 03/10/2025 16.18, Gustavo Romero wrote:
> The goal of this series is to remove Avocado as a dependency for running
> the reverse_debugging functional test.
> 
> After several rounds of discussions about v1 and v2, and experiments
> done by Daniel and Thomas (thanks for all the experiments and comments
> so far), I've taken a new approach and moved away from using a runner
> for GDB. The changes, I believe, are much simpler now.
> 
> This new series uses GDB's machine interface (MI) via the pygdbmi module
> (thanks Manos and Peter for the inputs). pygdbmi provides a controller
> to start GDB and communicate with it through MI, so there is no longer a
> risk of version clashes between libpython in GDB and Python modules in
> the pyvenv, as it could, in theory, happen when GDB executes the test
> script via -x option.
> 
> Also, as Daniel pointed out, the overall test output is pretty bad and
> currently does not allow one to easily follow the sequence of GDB
> commands used in the test. I took this opportunity to improve the output
> and it now prints the sequence in a format that can be copied and pasted
> directly into GDB.
> 
> The TAP protocol is respected, and Meson correctly displays GDB's test
> output in testlog-thorough.txt.
> 
> Because the pygdbmi "shim" is so thin, I had to write a trivial GDB
> class around it to easily capture and print the payloads returned by its
> write() method. The GDB class allows clean, single-line commands to be
> used in the tests through method chaining, making them easier to follow,
> for example:
> 
> pc = gdb.cli("print $pc").get_add()
> 
> The test is kept “skipped” for aarch64, ppc64, and x86_64, so it is
> necessary to set QEMU_TEST_FLAKY_TESTS=1 in the test environment to
> effectively run the test on these archs.
> 
> On aarch64, the test is flaky, but there is a fix that I’ve tested while
> writing this series [0] that resolves it. On ppc64 and x86_64, the test
> always fails: on ppc64, GDB gets a bogus PC, and on x86_64, the last
> part of the test (reverse-continue) does not hit the last executed PC
> (as it should happen) but instead jumps to the beginning of the code
> (first PC in forward order).
> 
> Thus, to effectively run the reverse_debugging test on aarch64:
> 
> $ export QEMU_TEST_FLAKY_TESTS=1
> $ make check-functional
> 
> or:
> $ make check-functional-aarch64
> 
> or even, to run only the reverse_debug test after 'make check-functional':
> $ ./pyvenv/bin/meson test --verbose --no-rebuild -t 1 --setup thorough --suite func-thorough func-aarch64-reverse_debug
> 
> 
> Cheers,
> Gustavo
> 
> v1:
> https://patchew.org/QEMU/20250819143916.4138035-1-gustavo.romero@linaro.org/
> 
> v2:
> https://patchew.org/QEMU/20250904154640.52687-1-gustavo.romero@linaro.org/
> 
> v3:
> https://patchew.org/QEMU/20250922054351.14289-1-gustavo.romero@linaro.org/
> 
> v4:
> https://patchew.org/QEMU/20250926051542.104432-1-gustavo.romero@linaro.org/
> 
> v5:
> https://patchew.org/QEMU/20251002020432.54443-1-gustavo.romero@linaro.org/
> 
> v6:
> - Fixed skipping test when no GDB is installed in the test environment

With this v6, the test now gets skipped in my incremental build directory, 
and it works when I compile QEMU in a new folder. I guess that's good 
enough, so from my side, it's fine to include this now:

Tested-by: Thomas Huth <thuth@redhat.com>

Alex, will you queue the patches?

  Thomas

Re: [PATCH v6 4/9] tests/functional: Add GDB class

[Alex Bennée]

Thomas Huth <thuth@redhat.com> writes:

> On 03/10/2025 16.18, Gustavo Romero wrote:
>> Add GDB class, which provides methods to run GDB commands and capture
>> their output. The GDB class is a wrapper around the pygdbmi module and
>> interacts with GDB via GDB's machine interface (MI).
>> Acked-by: Thomas Huth <thuth@redhat.com>
>> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
>> Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
>> ---
>>   tests/functional/qemu_test/__init__.py |  1 +
>>   tests/functional/qemu_test/gdb.py      | 88 ++++++++++++++++++++++++++
>>   2 files changed, 89 insertions(+)
>>   create mode 100644 tests/functional/qemu_test/gdb.py
>> diff --git a/tests/functional/qemu_test/__init__.py
>> b/tests/functional/qemu_test/__init__.py
>> index 6e666a059f..60d19891bf 100644
>> --- a/tests/functional/qemu_test/__init__.py
>> +++ b/tests/functional/qemu_test/__init__.py
>> @@ -18,3 +18,4 @@
>>       skipIfMissingImports, skipIfOperatingSystem, skipLockedMemoryTest
>>   from .archive import archive_extract
>>   from .uncompress import uncompress
>> +from .gdb import GDB
>> diff --git a/tests/functional/qemu_test/gdb.py b/tests/functional/qemu_test/gdb.py
>> new file mode 100644
>> index 0000000000..05e4c29c2a
>> --- /dev/null
>> +++ b/tests/functional/qemu_test/gdb.py
>> @@ -0,0 +1,88 @@
>> +# SPDX-License-Identifier: GPL-2.0-or-later
>> +#
>> +# A simple interface module built around pygdbmi for handling GDB commands.
>> +#
>> +# Copyright (c) 2025 Linaro Limited
>> +#
>> +# Author:
>> +#  Gustavo Romero <gustavo.romero@linaro.org>
>> +#
>> +# This work is licensed under the terms of the GNU GPL, version 2 or
>> +# later.  See the COPYING file in the top-level directory.
>
>  Hi,
>
> just as a reminder, this still needs the change requested by Daniel:
>
> https://lore.kernel.org/qemu-devel/aN56GkbIFxs5IDRR@redhat.com/

I've fixed that up in my current PR branch:

  https://gitlab.com/stsquad/qemu/-/commits/pr/031025-10.2-maintainer-1
  
>
>  Thomas

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro

Re: [PATCH v6 0/9] tests/functional: Adapt reverse_debugging to run w/o Avocado

[Alex Bennée]

Thomas Huth <thuth@redhat.com> writes:

> On 03/10/2025 16.18, Gustavo Romero wrote:
>> The goal of this series is to remove Avocado as a dependency for running
>> the reverse_debugging functional test.
>> After several rounds of discussions about v1 and v2, and experiments
>> done by Daniel and Thomas (thanks for all the experiments and comments
>> so far), I've taken a new approach and moved away from using a runner
>> for GDB. The changes, I believe, are much simpler now.
>> This new series uses GDB's machine interface (MI) via the pygdbmi
>> module
>> (thanks Manos and Peter for the inputs). pygdbmi provides a controller
>> to start GDB and communicate with it through MI, so there is no longer a
>> risk of version clashes between libpython in GDB and Python modules in
>> the pyvenv, as it could, in theory, happen when GDB executes the test
>> script via -x option.
>> Also, as Daniel pointed out, the overall test output is pretty bad
>> and
>> currently does not allow one to easily follow the sequence of GDB
>> commands used in the test. I took this opportunity to improve the output
>> and it now prints the sequence in a format that can be copied and pasted
>> directly into GDB.
>> The TAP protocol is respected, and Meson correctly displays GDB's
>> test
>> output in testlog-thorough.txt.
>> Because the pygdbmi "shim" is so thin, I had to write a trivial GDB
>> class around it to easily capture and print the payloads returned by its
>> write() method. The GDB class allows clean, single-line commands to be
>> used in the tests through method chaining, making them easier to follow,
>> for example:
>> pc = gdb.cli("print $pc").get_add()
>> The test is kept “skipped” for aarch64, ppc64, and x86_64, so it is
>> necessary to set QEMU_TEST_FLAKY_TESTS=1 in the test environment to
>> effectively run the test on these archs.
>> On aarch64, the test is flaky, but there is a fix that I’ve tested
>> while
>> writing this series [0] that resolves it. On ppc64 and x86_64, the test
>> always fails: on ppc64, GDB gets a bogus PC, and on x86_64, the last
>> part of the test (reverse-continue) does not hit the last executed PC
>> (as it should happen) but instead jumps to the beginning of the code
>> (first PC in forward order).
>> Thus, to effectively run the reverse_debugging test on aarch64:
>> $ export QEMU_TEST_FLAKY_TESTS=1
>> $ make check-functional
>> or:
>> $ make check-functional-aarch64
>> or even, to run only the reverse_debug test after 'make
>> check-functional':
>> $ ./pyvenv/bin/meson test --verbose --no-rebuild -t 1 --setup thorough --suite func-thorough func-aarch64-reverse_debug
>> Cheers,
>> Gustavo
>> v1:
>> https://patchew.org/QEMU/20250819143916.4138035-1-gustavo.romero@linaro.org/
>> v2:
>> https://patchew.org/QEMU/20250904154640.52687-1-gustavo.romero@linaro.org/
>> v3:
>> https://patchew.org/QEMU/20250922054351.14289-1-gustavo.romero@linaro.org/
>> v4:
>> https://patchew.org/QEMU/20250926051542.104432-1-gustavo.romero@linaro.org/
>> v5:
>> https://patchew.org/QEMU/20251002020432.54443-1-gustavo.romero@linaro.org/
>> v6:
>> - Fixed skipping test when no GDB is installed in the test environment
>
> With this v6, the test now gets skipped in my incremental build
> directory, and it works when I compile QEMU in a new folder. I guess
> that's good enough, so from my side, it's fine to include this now:
>
> Tested-by: Thomas Huth <thuth@redhat.com>
>
> Alex, will you queue the patches?

Yep - I'm just doing the final checks with my personal gitlab runners
before posting.

>
>  Thomas

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro