* [PATCH v4 0/1] util/async-teardown: wire up query-command-line-options
@ 2023-03-27 12:03 Claudio Imbrenda
2023-03-27 12:03 ` [PATCH v4 1/1] " Claudio Imbrenda
0 siblings, 1 reply; 3+ messages in thread
From: Claudio Imbrenda @ 2023-03-27 12:03 UTC (permalink / raw)
To: pbonzini
Cc: qemu-devel, david, thuth, borntraeger, frankja, fiuczy, pasic,
nsg, berrange, alex.bennee, armbru
The recently introduced -async-teardown commandline option was not
wired up properly and did not show up in the output of the QMP command
query-command-line-options. This means that libvirt will have no way to
discover whether the feature is supported.
This patch fixes the issue by adding a new -teardown commandline option
with an async=on|off parameter, correctly wired up so that it appears
in the output of query-command-line-options.
v3->v4
* completely remove the useless -async-teardown option, since it was
not wired up properly and it had no users [thomas]
* QEMU should be always uppercase in text and documentation [thomas]
* if the new -teardown option fails to parse, exit immediately instead
of returning an error [thomas]
v2->v3
* add a new teardown option with an async parameter [Markus]
* reworded documentation of existing -async-teardown option so that it
points to the new teardown option
v1->v2
* remove the unneeded .implied_opt_name initializer [Thomas]
Claudio Imbrenda (1):
util/async-teardown: wire up query-command-line-options
os-posix.c | 15 +++++++++++++--
qemu-options.hx | 33 +++++++++++++++++++--------------
util/async-teardown.c | 21 +++++++++++++++++++++
3 files changed, 53 insertions(+), 16 deletions(-)
--
2.39.2
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH v4 1/1] util/async-teardown: wire up query-command-line-options
2023-03-27 12:03 [PATCH v4 0/1] util/async-teardown: wire up query-command-line-options Claudio Imbrenda
@ 2023-03-27 12:03 ` Claudio Imbrenda
2023-03-27 12:59 ` Markus Armbruster
0 siblings, 1 reply; 3+ messages in thread
From: Claudio Imbrenda @ 2023-03-27 12:03 UTC (permalink / raw)
To: pbonzini
Cc: qemu-devel, david, thuth, borntraeger, frankja, fiuczy, pasic,
nsg, berrange, alex.bennee, armbru
The recently introduced -async-teardown commandline option was not
wired up properly and did not show up in the output of the QMP command
query-command-line-options. This means that libvirt had no way to
discover whether the feature was supported.
This patch fixes the issue by replacing the -async-teardown option with
a new -teardown option with a new async=on|off parameter.
The new option is correctly wired up so that it appears in the output
of query-command-line-options.
Reported-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Fixes: c891c24b1a ("os-posix: asynchronous teardown for shutdown on Linux")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
os-posix.c | 15 +++++++++++++--
qemu-options.hx | 33 +++++++++++++++++++--------------
util/async-teardown.c | 21 +++++++++++++++++++++
3 files changed, 53 insertions(+), 16 deletions(-)
diff --git a/os-posix.c b/os-posix.c
index 5adc69f560..c1ca7b1cb3 100644
--- a/os-posix.c
+++ b/os-posix.c
@@ -36,6 +36,8 @@
#include "qemu/log.h"
#include "sysemu/runstate.h"
#include "qemu/cutils.h"
+#include "qemu/config-file.h"
+#include "qemu/option.h"
#ifdef CONFIG_LINUX
#include <sys/prctl.h>
@@ -132,6 +134,8 @@ static bool os_parse_runas_uid_gid(const char *optarg)
*/
int os_parse_cmd_args(int index, const char *optarg)
{
+ QemuOpts *opts;
+
switch (index) {
case QEMU_OPTION_runas:
user_pwd = getpwnam(optarg);
@@ -152,8 +156,15 @@ int os_parse_cmd_args(int index, const char *optarg)
daemonize = 1;
break;
#if defined(CONFIG_LINUX)
- case QEMU_OPTION_asyncteardown:
- init_async_teardown();
+ case QEMU_OPTION_teardown:
+ opts = qemu_opts_parse_noisily(qemu_find_opts("teardown"),
+ optarg, false);
+ if (!opts) {
+ exit(1);
+ }
+ if (qemu_opt_get_bool(opts, "async", false)) {
+ init_async_teardown();
+ }
break;
#endif
default:
diff --git a/qemu-options.hx b/qemu-options.hx
index d42f60fb91..6a69b84f3c 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4763,23 +4763,28 @@ 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",
+DEF("teardown", HAS_ARG, QEMU_OPTION_teardown,
+ "-teardown async[=on|off]\n"
+ " process teardown options\n"
+ " async=on enables asynchronous teardown\n"
+ ,
QEMU_ARCH_ALL)
-#endif
SRST
-``-async-teardown``
- Enable asynchronous teardown. A new process called "cleanup/<QEMU_PID>"
- will be created at startup sharing the address space with the main qemu
- process, using clone. It will wait for the main qemu process to
- terminate completely, and then exit.
- This allows qemu to terminate very quickly even if the guest was
- huge, leaving the teardown of the address space to the cleanup
- process. Since the cleanup process shares the same cgroups as the
- main qemu process, accounting is performed correctly. This only
- works if the cleanup process is not forcefully killed with SIGKILL
- before the main qemu process has terminated completely.
+``-teardown``
+ Set process teardown options.
+
+ ``async=on`` enables asynchronous teardown. A new process called
+ "cleanup/<QEMU_PID>" will be created at startup sharing the address
+ space with the main QEMU process, using clone. It will wait for the
+ main QEMU process to terminate completely, and then exit. This allows
+ QEMU to terminate very quickly even if the guest was huge, leaving the
+ teardown of the address space to the cleanup process. Since the cleanup
+ process shares the same cgroups as the main QEMU process, accounting is
+ performed correctly. This only works if the cleanup process is not
+ forcefully killed with SIGKILL before the main QEMU process has
+ terminated completely.
ERST
+#endif
DEF("msg", HAS_ARG, QEMU_OPTION_msg,
"-msg [timestamp[=on|off]][,guest-name=[on|off]]\n"
diff --git a/util/async-teardown.c b/util/async-teardown.c
index 62cdeb0f20..4a5dbce958 100644
--- a/util/async-teardown.c
+++ b/util/async-teardown.c
@@ -12,6 +12,9 @@
*/
#include "qemu/osdep.h"
+#include "qemu/config-file.h"
+#include "qemu/option.h"
+#include "qemu/module.h"
#include <dirent.h>
#include <sys/prctl.h>
#include <sched.h>
@@ -144,3 +147,21 @@ void init_async_teardown(void)
clone(async_teardown_fn, new_stack_for_clone(), CLONE_VM, NULL);
sigprocmask(SIG_SETMASK, &old_signals, NULL);
}
+
+static QemuOptsList qemu_teardown_opts = {
+ .name = "teardown",
+ .head = QTAILQ_HEAD_INITIALIZER(qemu_teardown_opts.head),
+ .desc = {
+ {
+ .name = "async",
+ .type = QEMU_OPT_BOOL,
+ },
+ { /* end of list */ }
+ },
+};
+
+static void register_teardown(void)
+{
+ qemu_add_opts(&qemu_teardown_opts);
+}
+opts_init(register_teardown);
--
2.39.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v4 1/1] util/async-teardown: wire up query-command-line-options
2023-03-27 12:03 ` [PATCH v4 1/1] " Claudio Imbrenda
@ 2023-03-27 12:59 ` Markus Armbruster
0 siblings, 0 replies; 3+ messages in thread
From: Markus Armbruster @ 2023-03-27 12:59 UTC (permalink / raw)
To: Claudio Imbrenda
Cc: pbonzini, qemu-devel, david, thuth, borntraeger, frankja, fiuczy,
pasic, nsg, berrange, alex.bennee
Claudio Imbrenda <imbrenda@linux.ibm.com> writes:
> The recently introduced -async-teardown commandline option was not
> wired up properly and did not show up in the output of the QMP command
> query-command-line-options. This means that libvirt had no way to
> discover whether the feature was supported.
Excuse the pedantry... The option *was* wired up correctly, just in a
way that isn't visible in query-command-line-options. Suggest "The
recently introduced -async-teardown command line option -async-teardown
is not visible in query-command-line-options."
> This patch fixes the issue by replacing the -async-teardown option with
> a new -teardown option with a new async=on|off parameter.
Why we can drop -async-teardown right away, without a deprecating it
first? The commit message needs to make the argument.
If we can drop it right away, you need to update
about/removed-features.rst.
Else, you need to update docs/about/deprecated.rst, and emit a warning
when the option is used. Something like
warn_reportf("-async-teardown is deprecated, use -teardown async=on instead");
> The new option is correctly wired up so that it appears in the output
> of query-command-line-options.
Suggest
Add new -teardown option with an async=on|off parameter. It is
visible in query-command-line-options.
Then either
Option -async-teardown is now redundant. We'd normally deprecate it
and remove it after a grace period, but <argument goes here...>
Drop it.
or
Option -async-teardown is now redundant. Deprecate it.
> Reported-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
> Fixes: c891c24b1a ("os-posix: asynchronous teardown for shutdown on Linux")
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-03-27 12:03 [PATCH v4 0/1] util/async-teardown: wire up query-command-line-options Claudio Imbrenda
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