From: Li Zhang <zhlcindy@gmail.com>
To: armbru@redhat.com, marcandre.lureau@redhat.com, qemu-devel@nongnu.org
Cc: Li Zhang <li.zhang@cloud.ionos.com>,
Pankaj Gupta <pankaj.gupta@ionos.com>
Subject: [PATCHv2 1/1] Support monitor chardev hotswap with QMP
Date: Tue, 13 Apr 2021 23:34:59 +0200 [thread overview]
Message-ID: <20210413213459.629963-1-li.zhang@cloud.ionos.com> (raw)
For some scenarios, it needs to hot-add a monitor device.
But QEMU doesn't support hotplug yet. It also works by adding
a monitor with null backend by default and then change its
backend to socket by QMP command "chardev-change".
So this patch is to support monitor chardev hotswap with QMP.
Signed-off-by: Li Zhang <li.zhang@cloud.ionos.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@ionos.com>
---
v1 -> v2:
- Change mutex lock mon_lock section
- Fix indentation problems
monitor/monitor-internal.h | 3 +++
monitor/monitor.c | 2 +-
monitor/qmp.c | 43 +++++++++++++++++++++++++++++++++++---
3 files changed, 44 insertions(+), 4 deletions(-)
diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h
index 9c3a09cb01..1b80c74883 100644
--- a/monitor/monitor-internal.h
+++ b/monitor/monitor-internal.h
@@ -183,4 +183,7 @@ void help_cmd(Monitor *mon, const char *name);
void handle_hmp_command(MonitorHMP *mon, const char *cmdline);
int hmp_compare_cmd(const char *name, const char *list);
+gboolean monitor_unblocked(GIOChannel *chan, GIOCondition cond,
+ void *opaque);
+
#endif
diff --git a/monitor/monitor.c b/monitor/monitor.c
index 636bcc81c5..16a3620d02 100644
--- a/monitor/monitor.c
+++ b/monitor/monitor.c
@@ -157,7 +157,7 @@ static inline bool monitor_is_hmp_non_interactive(const Monitor *mon)
static void monitor_flush_locked(Monitor *mon);
-static gboolean monitor_unblocked(GIOChannel *chan, GIOCondition cond,
+gboolean monitor_unblocked(GIOChannel *chan, GIOCondition cond,
void *opaque)
{
Monitor *mon = opaque;
diff --git a/monitor/qmp.c b/monitor/qmp.c
index 2b0308f933..5fa65401ae 100644
--- a/monitor/qmp.c
+++ b/monitor/qmp.c
@@ -44,6 +44,7 @@ struct QMPRequest {
Error *err;
};
typedef struct QMPRequest QMPRequest;
+static void monitor_qmp_set_handlers_bh(void *opaque);
QmpCommandList qmp_commands, qmp_cap_negotiation_commands;
@@ -477,7 +478,36 @@ void monitor_data_destroy_qmp(MonitorQMP *mon)
g_queue_free(mon->qmp_requests);
}
-static void monitor_qmp_setup_handlers_bh(void *opaque)
+static int monitor_qmp_change(void *opaque)
+{
+ MonitorQMP *mon = opaque;
+
+ mon->common.use_io_thread = qemu_chr_has_feature(mon->common.chr.chr,
+ QEMU_CHAR_FEATURE_GCONTEXT);
+
+ if (mon->common.use_io_thread) {
+ aio_bh_schedule_oneshot(iothread_get_aio_context(mon_iothread),
+ monitor_qmp_set_handlers_bh, mon);
+ } else {
+ qemu_chr_fe_set_handlers(&mon->common.chr, monitor_can_read,
+ monitor_qmp_read, monitor_qmp_event,
+ monitor_qmp_change, &mon->common, NULL, true);
+ }
+
+ qemu_mutex_lock(&mon->common.mon_lock);
+ if (mon->common.out_watch) {
+ g_source_remove(mon->common.out_watch);
+ mon->common.out_watch = qemu_chr_fe_add_watch(&mon->common.chr,
+ G_IO_OUT | G_IO_HUP,
+ monitor_unblocked,
+ &mon->common);
+ }
+ qemu_mutex_unlock(&mon->common.mon_lock);
+
+ return 0;
+}
+
+static void monitor_qmp_set_handlers_bh(void *opaque)
{
MonitorQMP *mon = opaque;
GMainContext *context;
@@ -487,7 +517,14 @@ static void monitor_qmp_setup_handlers_bh(void *opaque)
assert(context);
qemu_chr_fe_set_handlers(&mon->common.chr, monitor_can_read,
monitor_qmp_read, monitor_qmp_event,
- NULL, &mon->common, context, true);
+ monitor_qmp_change, &mon->common, context, true);
+
+}
+
+static void monitor_qmp_setup_handlers_bh(void *opaque)
+{
+ MonitorQMP *mon = opaque;
+ monitor_qmp_set_handlers_bh(mon);
monitor_list_append(&mon->common);
}
@@ -528,7 +565,7 @@ void monitor_init_qmp(Chardev *chr, bool pretty, Error **errp)
} else {
qemu_chr_fe_set_handlers(&mon->common.chr, monitor_can_read,
monitor_qmp_read, monitor_qmp_event,
- NULL, &mon->common, NULL, true);
+ monitor_qmp_change, &mon->common, NULL, true);
monitor_list_append(&mon->common);
}
}
--
2.25.1
next reply other threads:[~2021-04-13 21:43 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-13 21:34 Li Zhang [this message]
2021-04-15 15:07 ` [PATCHv2 1/1] Support monitor chardev hotswap with QMP Li Zhang
2021-04-16 14:50 ` Markus Armbruster
2021-04-16 14:59 ` Marc-André Lureau
2021-04-16 15:28 ` Marc-André Lureau
2021-04-16 15:46 ` Li Zhang
2021-04-17 8:02 ` Markus Armbruster
2021-04-19 11:56 ` Li Zhang
2021-05-04 6:29 ` Pankaj Gupta
2021-05-04 8:38 ` Daniel P. Berrangé
2021-04-16 15:20 ` Li Zhang
2021-04-17 8:05 ` Markus Armbruster
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