[Qemu-devel] [PATCH v4] qapi: Add device ID and head parameters to screendump

* [Qemu-devel] [PATCH v4] qapi: Add device ID and head parameters to screendump
@ 2018-03-05 16:37 Thomas Huth
  2018-03-05 16:50 ` Eric Blake
  2018-03-11  3:05 ` Eric Blake
  0 siblings, 2 replies; 5+ messages in thread
From: Thomas Huth @ 2018-03-05 16:37 UTC (permalink / raw)
  To: qemu-devel, Gerd Hoffmann, Eric Blake
  Cc: Markus Armbruster, Dr. David Alan Gilbert,
	Daniel P. Berrangé,
	Jiri Denemark

QEMU's screendump command can only take dumps from the primary display.
When using multiple VGA cards, there is no way to get a dump from a
secondary card or other display heads yet. So let's add an 'device' and
a 'head' parameter to the HMP and QMP commands to be able to specify
alternative devices and heads with the screendump command, too.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 v4:
 - Improved the documentation of the parameters in ui.json a little bit
   (according to the suggestions from Eric)

 hmp-commands.hx |  7 ++++---
 hmp.c           |  4 +++-
 qapi/ui.json    | 10 +++++++++-
 ui/console.c    | 24 +++++++++++++++++++-----
 4 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index 964eb51..1723cbe 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -253,9 +253,10 @@ ETEXI
 
     {
         .name       = "screendump",
-        .args_type  = "filename:F",
-        .params     = "filename",
-        .help       = "save screen into PPM image 'filename'",
+        .args_type  = "filename:F,device:s?,head:i?",
+        .params     = "filename [device [head]]",
+        .help       = "save screen from head 'head' of display device 'device' "
+                      "into PPM image 'filename'",
         .cmd        = hmp_screendump,
     },
 
diff --git a/hmp.c b/hmp.c
index 016cb5c..ba9e299 100644
--- a/hmp.c
+++ b/hmp.c
@@ -2140,9 +2140,11 @@ err_out:
 void hmp_screendump(Monitor *mon, const QDict *qdict)
 {
     const char *filename = qdict_get_str(qdict, "filename");
+    const char *id = qdict_get_try_str(qdict, "device");
+    int64_t head = qdict_get_try_int(qdict, "head", 0);
     Error *err = NULL;
 
-    qmp_screendump(filename, &err);
+    qmp_screendump(filename, id != NULL, id, id != NULL, head, &err);
     hmp_handle_error(mon, &err);
 }
 
diff --git a/qapi/ui.json b/qapi/ui.json
index 3e82f25..5d01ad4 100644
--- a/qapi/ui.json
+++ b/qapi/ui.json
@@ -77,6 +77,13 @@
 #
 # @filename: the path of a new PPM file to store the image
 #
+# @device: ID of the display device that should be dumped. If this parameter
+#          is missing, the primary display will be used. (Since 2.12)
+#
+# @head: head to use in case the device supports multiple heads. If this
+#        parameter is missing, head #0 will be used. Also note that the head
+#        can only be specified in conjunction with the device ID. (Since 2.12)
+#
 # Returns: Nothing on success
 #
 # Since: 0.14.0
@@ -88,7 +95,8 @@
 # <- { "return": {} }
 #
 ##
-{ 'command': 'screendump', 'data': {'filename': 'str'} }
+{ 'command': 'screendump',
+  'data': {'filename': 'str', '*device': 'str', '*head': 'int'} }
 
 ##
 # == Spice
diff --git a/ui/console.c b/ui/console.c
index 6a1f499..f2794c7 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -344,14 +344,28 @@ write_err:
     goto out;
 }
 
-void qmp_screendump(const char *filename, Error **errp)
+void qmp_screendump(const char *filename, bool has_device, const char *device,
+                    bool has_head, int64_t head, Error **errp)
 {
-    QemuConsole *con = qemu_console_lookup_by_index(0);
+    QemuConsole *con;
     DisplaySurface *surface;
 
-    if (con == NULL) {
-        error_setg(errp, "There is no QemuConsole I can screendump from.");
-        return;
+    if (has_device) {
+        con = qemu_console_lookup_by_device_name(device, has_head ? head : 0,
+                                                 errp);
+        if (!con) {
+            return;
+        }
+    } else {
+        if (has_head) {
+            error_setg(errp, "'head' must be specified together with 'device'");
+            return;
+        }
+        con = qemu_console_lookup_by_index(0);
+        if (!con) {
+            error_setg(errp, "There is no console to take a screendump from");
+            return;
+        }
     }
 
     graphic_hw_update(con);
-- 
1.8.3.1

^ permalink raw reply related	[flat|nested] 5+ messages in thread