It's been marked as deprecated since QEMU 8.1 (and was only available
since QEMU 8.0 anyway), so it should be fine to remove this now.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 docs/about/deprecated.rst       |  5 -----
 docs/about/removed-features.rst |  5 +++++
 system/vl.c                     |  6 ------
 qemu-options.hx                 | 10 ----------
 4 files changed, 5 insertions(+), 21 deletions(-)

diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index 3f8e505df6..89ca4490d7 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -63,11 +63,6 @@ as short-form boolean values, and passed to plugins as ``arg_name=on``.
 However, short-form booleans are deprecated and full explicit ``arg_name=on``
 form is preferred.
 
-``-async-teardown`` (since 8.1)
-'''''''''''''''''''''''''''''''
-
-Use ``-run-with async-teardown=on`` instead.
-
 ``-chroot`` (since 8.1)
 '''''''''''''''''''''''
 
diff --git a/docs/about/removed-features.rst b/docs/about/removed-features.rst
index ae728b6130..43f64a26ba 100644
--- a/docs/about/removed-features.rst
+++ b/docs/about/removed-features.rst
@@ -472,6 +472,11 @@ Use ``-machine hpet=off`` instead.
 The ``-no-acpi`` setting has been turned into a machine property.
 Use ``-machine acpi=off`` instead.
 
+``-async-teardown`` (removed in 9.0)
+''''''''''''''''''''''''''''''''''''
+
+Use ``-run-with async-teardown=on`` instead.
+
 
 QEMU Machine Protocol (QMP) commands
 ------------------------------------
diff --git a/system/vl.c b/system/vl.c
index 7e258889f3..924356f864 100644
--- a/system/vl.c
+++ b/system/vl.c
@@ -3600,12 +3600,6 @@ void qemu_init(int argc, char **argv)
             case QEMU_OPTION_daemonize:
                 os_set_daemonize(true);
                 break;
-#if defined(CONFIG_LINUX)
-            /* deprecated */
-            case QEMU_OPTION_asyncteardown:
-                init_async_teardown();
-                break;
-#endif
             case QEMU_OPTION_run_with: {
                 const char *str;
                 opts = qemu_opts_parse_noisily(qemu_find_opts("run-with"),
diff --git a/qemu-options.hx b/qemu-options.hx
index dafecf47d6..10c952ba3f 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4975,16 +4975,6 @@ HXCOMM Internal use
 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
 
-#ifdef __linux__
-DEF("async-teardown", 0, QEMU_OPTION_asyncteardown,
-    "-async-teardown enable asynchronous teardown\n",
-    QEMU_ARCH_ALL)
-SRST
-``-async-teardown``
-    This option is deprecated and should no longer be used. The new option
-    ``-run-with async-teardown=on`` is a replacement.
-ERST
-#endif
 #ifdef CONFIG_POSIX
 DEF("run-with", HAS_ARG, QEMU_OPTION_run_with,
     "-run-with [async-teardown=on|off][,chroot=dir]\n"
-- 
2.43.0