From: Li Zhang <zhlcindy@gmail.com>
To: Markus Armbruster <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: Re: [PATCHv2 1/1] Support monitor chardev hotswap with QMP
Date: Thu, 15 Apr 2021 17:07:35 +0200 [thread overview]
Message-ID: <CAD8of+o43USAaRu7zJTynKvgT2FaJ7U69SMxZ50gUVBYMtQaSg@mail.gmail.com> (raw)
In-Reply-To: <20210413213459.629963-1-li.zhang@cloud.ionos.com>
Ping
On Tue, Apr 13, 2021 at 11:37 PM Li Zhang <zhlcindy@gmail.com> wrote:
>
> 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
>
--
Best Regards
-Li
next prev parent reply other threads:[~2021-04-15 15:10 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-13 21:34 [PATCHv2 1/1] Support monitor chardev hotswap with QMP Li Zhang
2021-04-15 15:07 ` Li Zhang [this message]
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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