hmp: Make "info block" output more readable

HMP is meant for humans and you should notice it.

This changes the output format to use a bit more space to display the
information more readable and leaves out irrelevant information (e.g.
mention only that an image is encrypted, but not when it's not; display
I/O limits only if throttling is in effect; ...)

Before:

    (qemu) info block
    ide0-hd0: removable=0 io-status=ok file=/tmp/overlay.qcow2
    backing_file=/tmp/backing.img backing_file_depth=1 ro=0 drv=qcow2
    encrypted=1 bps=0 bps_rd=0 bps_wr=0 iops=1024 iops_rd=0 iops_wr=0
    ide1-cd0: removable=1 locked=0 tray-open=0 io-status=ok
    file=/home/kwolf/images/iso/Fedora-18-x86_64-Live-Desktop.iso ro=1
    drv=raw encrypted=0 bps=0 bps_rd=0 bps_wr=0 iops=0 iops_rd=0 iops_wr=0
    floppy0: removable=1 locked=0 tray-open=0 [not inserted]
    sd0: removable=1 locked=0 tray-open=0 [not inserted]

After:

    (qemu) info block
    ide0-hd0: /tmp/overlay.qcow2 (qcow2, encrypted)
        Backing file:     /tmp/backing.img (chain depth: 1)
        I/O limits:       bps=0 bps_rd=0 bps_wr=0 iops=1024 iops_rd=0 iops_wr=0

    ide1-cd0: /home/kwolf/images/iso/Fedora-18-x86_64-Live-Desktop.iso (raw, read-only)
        Removable device: not locked, tray closed

    floppy0: [not inserted]
        Removable device: not locked, tray closed

    sd0: [not inserted]
        Removable device: not locked, tray closed
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Acked-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

hmp.c

@@ -291,62 +291,78 @@ void hmp_info_block(Monitor *mon, const QDict *qdict)
         if (device && strcmp(device, info->value->device)) {
             continue;
         }
-        monitor_printf(mon, "%s: removable=%d",
-                       info->value->device, info->value->removable);
 
-        if (info->value->removable) {
-            monitor_printf(mon, " locked=%d", info->value->locked);
-            monitor_printf(mon, " tray-open=%d", info->value->tray_open);
+        if (info != block_list) {
+            monitor_printf(mon, "\n");
+        }
+
+        monitor_printf(mon, "%s", info->value->device);
+        if (info->value->has_inserted) {
+            monitor_printf(mon, ": %s (%s%s%s)\n",
+                           info->value->inserted->file,
+                           info->value->inserted->drv,
+                           info->value->inserted->ro ? ", read-only" : "",
+                           info->value->inserted->encrypted ? ", encrypted" : "");
+        } else {
+            monitor_printf(mon, ": [not inserted]\n");
         }
 
-        if (info->value->has_io_status) {
-            monitor_printf(mon, " io-status=%s",
+        if (info->value->has_io_status && info->value->io_status != BLOCK_DEVICE_IO_STATUS_OK) {
+            monitor_printf(mon, "    I/O status:       %s\n",
                            BlockDeviceIoStatus_lookup[info->value->io_status]);
         }
 
-        if (info->value->has_inserted) {
-            monitor_printf(mon, " file=");
-            monitor_print_filename(mon, info->value->inserted->file);
-
-            if (info->value->inserted->has_backing_file) {
-                monitor_printf(mon, " backing_file=");
-                monitor_print_filename(mon, info->value->inserted->backing_file);
-                monitor_printf(mon, " backing_file_depth=%" PRId64,
-                    info->value->inserted->backing_file_depth);
-            }
-            monitor_printf(mon, " ro=%d drv=%s encrypted=%d",
-                           info->value->inserted->ro,
-                           info->value->inserted->drv,
-                           info->value->inserted->encrypted);
+        if (info->value->removable) {
+            monitor_printf(mon, "    Removable device: %slocked, tray %s\n",
+                           info->value->locked ? "" : "not ",
+                           info->value->tray_open ? "open" : "closed");
+        }
 
-            monitor_printf(mon, " bps=%" PRId64 " bps_rd=%" PRId64
-                            " bps_wr=%" PRId64 " iops=%" PRId64
-                            " iops_rd=%" PRId64 " iops_wr=%" PRId64,
+
+        if (!info->value->has_inserted) {
+            continue;
+        }
+
+        if (info->value->inserted->has_backing_file) {
+            monitor_printf(mon,
+                           "    Backing file:     %s "
+                           "(chain depth: %" PRId64 ")\n",
+                           info->value->inserted->backing_file,
+                           info->value->inserted->backing_file_depth);
+        }
+
+        if (info->value->inserted->bps
+            || info->value->inserted->bps_rd
+            || info->value->inserted->bps_wr
+            || info->value->inserted->iops
+            || info->value->inserted->iops_rd
+            || info->value->inserted->iops_wr)
+        {
+            monitor_printf(mon, "    I/O throttling:   bps=%" PRId64
+                            " bps_rd=%" PRId64  " bps_wr=%" PRId64
+                            " iops=%" PRId64 " iops_rd=%" PRId64
+                            " iops_wr=%" PRId64 "\n",
                             info->value->inserted->bps,
                             info->value->inserted->bps_rd,
                             info->value->inserted->bps_wr,
                             info->value->inserted->iops,
                             info->value->inserted->iops_rd,
                             info->value->inserted->iops_wr);
+        }
 
-            if (verbose) {
-                monitor_printf(mon, " images:\n");
-                image_info = info->value->inserted->image;
-                while (1) {
-                        bdrv_image_info_dump((fprintf_function)monitor_printf,
-                                             mon, image_info);
-                    if (image_info->has_backing_image) {
-                        image_info = image_info->backing_image;
-                    } else {
-                        break;
-                    }
+        if (verbose) {
+            monitor_printf(mon, "\nImages:\n");
+            image_info = info->value->inserted->image;
+            while (1) {
+                    bdrv_image_info_dump((fprintf_function)monitor_printf,
+                                         mon, image_info);
+                if (image_info->has_backing_image) {
+                    image_info = image_info->backing_image;
+                } else {
+                    break;
                 }
             }
-        } else {
-            monitor_printf(mon, " [not inserted]");
         }
-
-        monitor_printf(mon, "\n");
     }
 
     qapi_free_BlockInfoList(block_list);