[Qemu-devel] [RfC PATCH 2/2] console: add screendump-device qmp cmd

[Gerd Hoffmann <kraxel@redhat.com>]

Adds a screendump-device qmp command, which has an additional 'device'
parameter.  This way it is possible to specify the device you want a
screendump from.

For the hmp monitor an optional device parameter has been added to the
esisting screendump command.

https://bugzilla.redhat.com/show_bug.cgi?id=903910

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 qapi-schema.json |   15 +++++++++++++++
 qmp-commands.hx  |   25 +++++++++++++++++++++++++
 ui/console.c     |   52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 92 insertions(+)

diff --git a/qapi-schema.json b/qapi-schema.json
index adcf801..719dc6e 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3125,6 +3125,21 @@
 { 'command': 'screendump', 'data': {'filename': 'str'} }
 
 ##
+# @screendump-device:
+#
+# Write a PPM from the specified device to a file.
+#
+# @filename: the path of a new PPM file to store the image
+# @device: #optional device to take the screenshot from
+#
+# Returns: Nothing on success
+#
+# Since: 1.6
+##
+{ 'command': 'screendump-device', 'data': {'filename': 'str',
+                                           '*device' : 'str' }}
+
+##
 # @nbd-server-start:
 #
 # Start an NBD server listening on the given host and port.  Block
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 8e69fba..6361561 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -167,6 +167,31 @@ Example:
 EQMP
 
     {
+        .name       = "screendump-device",
+        .args_type  = "filename:F,device:B?",
+        .mhandler.cmd_new = qmp_marshal_input_screendump_device,
+    },
+
+SQMP
+screendump-device
+-----------------
+
+Save screen into PPM image.
+
+Arguments:
+
+- "filename": file path (json-string)
+- "device": video device (json-string, optional)
+
+Example:
+
+-> { "execute": "screendump-device",
+     "arguments": { "filename": "/tmp/image", "device" : "video0" } }
+<- { "return": {} }
+
+EQMP
+
+    {
         .name       = "stop",
         .args_type  = "",
         .mhandler.cmd_new = qmp_marshal_input_stop,
diff --git a/ui/console.c b/ui/console.c
index 020805c..1895acf 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -343,6 +343,58 @@ void qmp_screendump(const char *filename, Error **errp)
     ppm_save(filename, surface, errp);
 }
 
+struct screendump_job {
+    QEMUBH *bh;
+    QemuConsole *con;
+    char *filename;
+};
+
+static void qmp_screendump_bh(void *opaque)
+{
+    Error *local_err;
+    struct screendump_job *j = opaque;
+    DisplaySurface *surface;
+
+    surface = qemu_console_surface(j->con);
+    ppm_save(j->filename, surface, &local_err);
+    /* TODO: send qmp completion (or error) event */
+    qemu_bh_delete(j->bh);
+    free(j->filename);
+    free(j);
+}
+
+void qmp_screendump_device(const char *filename,
+                           bool has_device, const char *device, Error **errp)
+{
+    struct screendump_job *j;
+    QemuConsole *con;
+
+    if (has_device) {
+        DeviceState *dev = qdev_find_recursive(sysbus_get_default(), device);
+        if (NULL == dev) {
+            error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+            return;
+        }
+        con = qemu_console_lookup_by_device(dev);
+        if (NULL == con) {
+            error_setg(errp, "There is no QemuConsole linked to %s", device);
+            return;
+        }
+    } else {
+        con = qemu_console_lookup_by_index(0);
+        if (con == NULL) {
+            error_setg(errp, "There is no QemuConsole I can screendump from.");
+            return;
+        }
+    }
+
+    j = g_new0(struct screendump_job, 1);
+    j->bh = qemu_bh_new(qmp_screendump_bh, j);
+    j->con = con;
+    j->filename = g_strdup(filename);
+    graphic_hw_update_notify(con, j->bh);
+}
+
 void graphic_hw_text_update(QemuConsole *con, console_ch_t *chardata)
 {
     if (!con) {
-- 
1.7.9.7