Patchwork [05/15] QMP: chardev handling

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Submitter Luiz Capitulino
Date Nov. 19, 2009, 3:13 p.m.
Message ID <1258643623-8636-6-git-send-email-lcapitulino@redhat.com>
Download mbox | patch
Permalink /patch/38848/
State New
Headers show

Comments

Luiz Capitulino - Nov. 19, 2009, 3:13 p.m.
This patch adds initial QMP support in QEMU. It's important
to notice that most QMP code will be part of the Monitor.

Input will be handled by monitor_control_read(). Currently it
reads the input and discards it, next patches add proper input
support.

The function monitor_json_emitter(), as its name implies, is
used by the Monitor to emit JSON output. In this commit it's
used by monitor_control_event() to print our greeting message.

Finally, control mode support is also added to monitor_init(),
allowing QMP to be really enabled.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 monitor.c |   78 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 76 insertions(+), 2 deletions(-)

Patch

diff --git a/monitor.c b/monitor.c
index 07bd21c..be68dd5 100644
--- a/monitor.c
+++ b/monitor.c
@@ -50,6 +50,7 @@ 
 #include "qdict.h"
 #include "qstring.h"
 #include "qerror.h"
+#include "qjson.h"
 
 //#define DEBUG
 //#define DEBUG_COMPLETION
@@ -92,6 +93,11 @@  struct mon_fd_t {
     QLIST_ENTRY(mon_fd_t) next;
 };
 
+typedef struct MonitorControl {
+    uint8_t buf[1024];
+    int size;
+} MonitorControl;
+
 struct Monitor {
     CharDriverState *chr;
     int mux_out;
@@ -101,6 +107,7 @@  struct Monitor {
     uint8_t outbuf[1024];
     int outbuf_index;
     ReadLineState *rs;
+    MonitorControl *mc;
     CPUState *mon_cpu;
     BlockDriverCompletionFunc *password_completion_cb;
     void *password_opaque;
@@ -255,6 +262,17 @@  static void monitor_print_qobject(Monitor *mon, const QObject *data)
     monitor_puts(mon, "\n");
 }
 
+static void monitor_json_emitter(Monitor *mon, const QObject *data)
+{
+    QString *json;
+
+    json = qobject_to_json(data);
+    assert(json != NULL);
+
+    monitor_printf(mon, "%s\n", qstring_get_str(json));
+    QDECREF(json);
+}
+
 static int compare_cmd(const char *name, const char *list)
 {
     const char *p, *pstart;
@@ -3530,6 +3548,37 @@  static int monitor_can_read(void *opaque)
     return (mon->suspend_cnt == 0) ? 128 : 0;
 }
 
+/**
+ * monitor_control_read(): Read and handle QMP input
+ */
+static void monitor_control_read(void *opaque, const uint8_t *buf, int size)
+{
+    Monitor *old_mon = cur_mon;
+    int i;
+
+    cur_mon = opaque;
+
+    for (i = 0; i < size; i++) {
+        if (buf[i] == '\r' || buf[i] == '\n') {
+            cur_mon->mc->buf[cur_mon->mc->size] = '\0';
+            cur_mon->mc->size = 0;
+
+            /* TODO: parse QMP input */
+            break;
+        } else {
+            cur_mon->mc->buf[cur_mon->mc->size++] = buf[i];
+            if (cur_mon->mc->size == sizeof(cur_mon->mc->buf)) {
+                /* FIXME: qemu_error_new() */
+                monitor_printf(cur_mon, "Command too long\n");
+                cur_mon->mc->size = 0;
+                break;
+            }
+        }
+    }
+
+    cur_mon = old_mon;
+}
+
 static void monitor_read(void *opaque, const uint8_t *buf, int size)
 {
     Monitor *old_mon = cur_mon;
@@ -3573,6 +3622,24 @@  void monitor_resume(Monitor *mon)
         readline_show_prompt(mon->rs);
 }
 
+/**
+ * monitor_control_event(): Print QMP gretting on RESET
+ */
+static void monitor_control_event(void *opaque, int event)
+{
+    if (event == CHR_EVENT_OPENED) {
+        QObject *data;
+        Monitor *mon = opaque;
+
+        data = qobject_from_jsonf("{ 'QMP': { 'capabilities': [] } }");
+        assert(data != NULL);
+        monitor_json_emitter(mon, data);
+        qobject_decref(data);
+
+        mon->mc->size = 0;
+    }
+}
+
 static void monitor_event(void *opaque, int event)
 {
     Monitor *mon = opaque;
@@ -3659,8 +3726,15 @@  void monitor_init(CharDriverState *chr, int flags)
         monitor_read_command(mon, 0);
     }
 
-    qemu_chr_add_handlers(chr, monitor_can_read, monitor_read, monitor_event,
-                          mon);
+    if (monitor_ctrl_mode(mon)) {
+        mon->mc = qemu_mallocz(sizeof(MonitorControl));
+        /* Control mode requires special handlers */
+        qemu_chr_add_handlers(chr, monitor_can_read, monitor_control_read,
+                              monitor_control_event, mon);
+    } else {
+        qemu_chr_add_handlers(chr, monitor_can_read, monitor_read,
+                              monitor_event, mon);
+    }
 
     QLIST_INSERT_HEAD(&mon_list, mon, entry);
     if (!cur_mon || (flags & MONITOR_IS_DEFAULT))