Re: [Qemu-devel] [PATCH v2 5/9] chardev: introduce chr_machine_done hook

[Daniel P . Berrangé]

On Tue, Mar 06, 2018 at 01:33:16PM +0800, Peter Xu wrote:
> Introduce ChardevClass.chr_machine_done() hook so that chardevs can run
> customized procedures after machine init.
> 
> There was an existing mux user already that did similar thing but used a
> raw machine done notifier.  Generalize it into a framework, and let the
> mux chardevs provide such a class-specific hook to achieve the same
> thing.  Then we can move the mux related code to the char-mux.c file.
> 
> Since at it, replace the mux_realized variable with the global
> machine_init_done varible.
> 
> This notifier framework will be further leverged by other type of
> chardevs soon.
> 
> Signed-off-by: Peter Xu 
> ---
>  chardev/char-mux.c | 33 +
>  chardev/char.c | 43 +--
>  include/chardev/char-mux.h |  2 --
>  include/chardev/char.h |  2 ++
>  tests/test-char.c  |  1 -
>  5 files changed, 48 insertions(+), 33 deletions(-)

Reviewed-by: Daniel P. Berrangé 


Regards,
Daniel
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[Qemu-devel] [PATCH v2 5/9] chardev: introduce chr_machine_done hook

[Peter Xu]

Introduce ChardevClass.chr_machine_done() hook so that chardevs can run
customized procedures after machine init.

There was an existing mux user already that did similar thing but used a
raw machine done notifier.  Generalize it into a framework, and let the
mux chardevs provide such a class-specific hook to achieve the same
thing.  Then we can move the mux related code to the char-mux.c file.

Since at it, replace the mux_realized variable with the global
machine_init_done varible.

This notifier framework will be further leverged by other type of
chardevs soon.

Signed-off-by: Peter Xu 
---
 chardev/char-mux.c | 33 +
 chardev/char.c | 43 +--
 include/chardev/char-mux.h |  2 --
 include/chardev/char.h |  2 ++
 tests/test-char.c  |  1 -
 5 files changed, 48 insertions(+), 33 deletions(-)

diff --git a/chardev/char-mux.c b/chardev/char-mux.c
index d48e78103a..1b925c8dec 100644
--- a/chardev/char-mux.c
+++ b/chardev/char-mux.c
@@ -27,6 +27,7 @@
 #include "qemu/option.h"
 #include "chardev/char.h"
 #include "sysemu/block-backend.h"
+#include "sysemu/sysemu.h"
 #include "chardev/char-mux.h"
 
 /* MUX driver for serial I/O splitting */
@@ -230,14 +231,12 @@ static void mux_chr_read(void *opaque, const uint8_t 
*buf, int size)
 }
 }
 
-bool muxes_realized;
-
 void mux_chr_send_all_event(Chardev *chr, int event)
 {
 MuxChardev *d = MUX_CHARDEV(chr);
 int i;
 
-if (!muxes_realized) {
+if (!machine_init_done) {
 return;
 }
 
@@ -327,7 +326,7 @@ static void qemu_chr_open_mux(Chardev *chr,
 /* only default to opened state if we've realized the initial
  * set of muxes
  */
-*be_opened = muxes_realized;
+*be_opened = machine_init_done;
 qemu_chr_fe_init(>chr, drv, errp);
 }
 
@@ -347,6 +346,31 @@ static void qemu_chr_parse_mux(QemuOpts *opts, 
ChardevBackend *backend,
 mux->chardev = g_strdup(chardev);
 }
 
+/**
+ * Called after processing of default and command-line-specified
+ * chardevs to deliver CHR_EVENT_OPENED events to any FEs attached
+ * to a mux chardev. This is done here to ensure that
+ * output/prompts/banners are only displayed for the FE that has
+ * focus when initial command-line processing/machine init is
+ * completed.
+ *
+ * After this point, any new FE attached to any new or existing
+ * mux will receive CHR_EVENT_OPENED notifications for the BE
+ * immediately.
+ */
+static int open_muxes(Chardev *chr)
+{
+/* send OPENED to all already-attached FEs */
+mux_chr_send_all_event(chr, CHR_EVENT_OPENED);
+/*
+ * mark mux as OPENED so any new FEs will immediately receive
+ * OPENED event
+ */
+qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+
+return 0;
+}
+
 static void char_mux_class_init(ObjectClass *oc, void *data)
 {
 ChardevClass *cc = CHARDEV_CLASS(oc);
@@ -357,6 +381,7 @@ static void char_mux_class_init(ObjectClass *oc, void *data)
 cc->chr_accept_input = mux_chr_accept_input;
 cc->chr_add_watch = mux_chr_add_watch;
 cc->chr_be_event = mux_chr_be_event;
+cc->chr_machine_done = open_muxes;
 }
 
 static const TypeInfo char_mux_type_info = {
diff --git a/chardev/char.c b/chardev/char.c
index 01d979a1da..fda820863c 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -281,40 +281,31 @@ static const TypeInfo char_type_info = {
 .class_init = char_class_init,
 };
 
-/**
- * Called after processing of default and command-line-specified
- * chardevs to deliver CHR_EVENT_OPENED events to any FEs attached
- * to a mux chardev. This is done here to ensure that
- * output/prompts/banners are only displayed for the FE that has
- * focus when initial command-line processing/machine init is
- * completed.
- *
- * After this point, any new FE attached to any new or existing
- * mux will receive CHR_EVENT_OPENED notifications for the BE
- * immediately.
- */
-static int open_muxes(Object *child, void *opaque)
+static int chardev_machine_done_notify_one(Object *child, void *opaque)
 {
-if (CHARDEV_IS_MUX(child)) {
-/* send OPENED to all already-attached FEs */
-mux_chr_send_all_event(CHARDEV(child), CHR_EVENT_OPENED);
-/* mark mux as OPENED so any new FEs will immediately receive
- * OPENED event
- */
-qemu_chr_be_event(CHARDEV(child), CHR_EVENT_OPENED);
+Chardev *chr = (Chardev *)child;
+ChardevClass *class = CHARDEV_GET_CLASS(chr);
+
+if (class->chr_machine_done) {
+return class->chr_machine_done(chr);
 }
 
 return 0;
 }
 
-static void muxes_realize_done(Notifier *notifier, void *unused)
+static void chardev_machine_done_hook(Notifier *notifier, void *unused)
 {
-muxes_realized = true;
-object_child_foreach(get_chardevs_root(), open_muxes, NULL);
+int ret = object_child_foreach(get_chardevs_root(),
+   chardev_machine_done_notify_one, NULL);
+
+if