qapi: Convert migrate

The migrate command is one of those commands where HMP and QMP completely
mix up together. This made the conversion to the QAPI (which separates the
command into QMP and HMP parts) a bit difficult.

The first important change to be noticed is that this commit completes the
removal of the Monitor object from migration code, started by the previous
commit.

Another important and tricky change is about supporting the non-detached
mode. That is, if the user doesn't pass '-d' the migrate command will lock
the monitor and will only release it when migration is finished.

To support this in the new HMP command (hmp_migrate()), it is necessary
to create a timer which runs every second and checks if the migration is
still active. If it is, the timer callback will re-schedule itself to run
one second in the future. If the migration has already finished, the
monitor lock is released and the user can use it normally.

All these changes should be transparent to the user.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

1 files changed, 74 insertions, 0 deletions

diff --git a/hmp.c b/hmp.c
index 290c43d..9cf2d13 100644
--- a/hmp.c
+++ b/hmp.c
@@ -14,6 +14,7 @@
  */
 
 #include "hmp.h"
+#include "qemu-timer.h"
 #include "qmp-commands.h"
 
 static void hmp_handle_error(Monitor *mon, Error **errp)
@@ -860,3 +861,76 @@ void hmp_block_job_cancel(Monitor *mon, const QDict *qdict)
 
     hmp_handle_error(mon, &error);
 }
+
+typedef struct MigrationStatus
+{
+    QEMUTimer *timer;
+    Monitor *mon;
+    bool is_block_migration;
+} MigrationStatus;
+
+static void hmp_migrate_status_cb(void *opaque)
+{
+    MigrationStatus *status = opaque;
+    MigrationInfo *info;
+
+    info = qmp_query_migrate(NULL);
+    if (!info->has_status || strcmp(info->status, "active") == 0) {
+        if (info->has_disk) {
+            int progress;
+
+            if (info->disk->remaining) {
+                progress = info->disk->transferred * 100 / info->disk->total;
+            } else {
+                progress = 100;
+            }
+
+            monitor_printf(status->mon, "Completed %d %%\r", progress);
+            monitor_flush(status->mon);
+        }
+
+        qemu_mod_timer(status->timer, qemu_get_clock_ms(rt_clock) + 1000);
+    } else {
+        if (status->is_block_migration) {
+            monitor_printf(status->mon, "\n");
+        }
+        monitor_resume(status->mon);
+        qemu_del_timer(status->timer);
+        g_free(status);
+    }
+
+    qapi_free_MigrationInfo(info);
+}
+
+void hmp_migrate(Monitor *mon, const QDict *qdict)
+{
+    int detach = qdict_get_try_bool(qdict, "detach", 0);
+    int blk = qdict_get_try_bool(qdict, "blk", 0);
+    int inc = qdict_get_try_bool(qdict, "inc", 0);
+    const char *uri = qdict_get_str(qdict, "uri");
+    Error *err = NULL;
+
+    qmp_migrate(uri, !!blk, blk, !!inc, inc, false, false, &err);
+    if (err) {
+        monitor_printf(mon, "migrate: %s\n", error_get_pretty(err));
+        error_free(err);
+        return;
+    }
+
+    if (!detach) {
+        MigrationStatus *status;
+
+        if (monitor_suspend(mon) < 0) {
+            monitor_printf(mon, "terminal does not allow synchronous "
+                           "migration, continuing detached\n");
+            return;
+        }
+
+        status = g_malloc0(sizeof(*status));
+        status->mon = mon;
+        status->is_block_migration = blk || inc;
+        status->timer = qemu_new_timer_ms(rt_clock, hmp_migrate_status_cb,
+                                          status);
+        qemu_mod_timer(status->timer, qemu_get_clock_ms(rt_clock));
+    }
+}