[Qemu-block] [PATCH 1/1] HMP: Add equivalent to x-blockdev-change

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <address@hidden>

x-blockdev-change has no HMP equivalent, so add x_block_change.

Example useages are:
x_block_change  foo -a bah
   to add the node bah to the parent foo

x_block_change  foo -d bah
   to delete the node bah from the parent foo

Signed-off-by: Dr. David Alan Gilbert <address@hidden>
---
 hmp-commands.hx | 18 ++++++++++++++++++
 hmp.c           | 20 ++++++++++++++++++++
 hmp.h           |  1 +
 3 files changed, 39 insertions(+)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index a381b0b..cf2459b 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -57,6 +57,24 @@ Quit the emulator.
 ETEXI
 
     {
+        .name       = "x_block_change",
+        .args_type  = "parent:B,add:-a,del:-d,child:B",
+        .params     = "parent [-a] [-d] child",
+        .help       = "add or remove a child from a block driver",
+        .mhandler.cmd = hmp_block_change,
+    },
+
+STEXI
address@hidden x_block_change
address@hidden x_block_change
+Dynamically reconfigure the block driver state graph. It can be used
+to add, remove, insert or replace a block driver state. Currently only
+the Quorum driver implements this feature to add or remove its child.
+This is useful to fix a broken quorum child.
+ETEXI
+
+
+    {
         .name       = "block_resize",
         .args_type  = "device:B,size:o",
         .params     = "device size",
diff --git a/hmp.c b/hmp.c
index dc6dc30..631dacb 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1042,6 +1042,26 @@ void hmp_balloon(Monitor *mon, const QDict *qdict)
     }
 }
 
+void hmp_block_change(Monitor *mon, const QDict *qdict)
+{
+    const char *parent = qdict_get_str(qdict, "parent");
+    const char *child = qdict_get_str(qdict, "child");
+    bool add = qdict_get_try_bool(qdict, "add", false);
+    bool del = qdict_get_try_bool(qdict, "del", false);
+    Error *err = NULL;
+
+    if (add == del) {
+        error_setg(&err, "One of -a or -d must be set");
+        hmp_handle_error(mon, &err);
+        return;
+    }
+
+    qmp_x_blockdev_change(parent,
+                          del, child,
+                          add, child, &err);
+    hmp_handle_error(mon, &err);
+}
+
 void hmp_block_resize(Monitor *mon, const QDict *qdict)
 {
     const char *device = qdict_get_str(qdict, "device");
diff --git a/hmp.h b/hmp.h
index 864a300..1588850 100644
--- a/hmp.h
+++ b/hmp.h
@@ -53,6 +53,7 @@ void hmp_cont(Monitor *mon, const QDict *qdict);
 void hmp_system_wakeup(Monitor *mon, const QDict *qdict);
 void hmp_nmi(Monitor *mon, const QDict *qdict);
 void hmp_set_link(Monitor *mon, const QDict *qdict);
+void hmp_block_change(Monitor *mon, const QDict *qdict);
 void hmp_block_passwd(Monitor *mon, const QDict *qdict);
 void hmp_balloon(Monitor *mon, const QDict *qdict);
 void hmp_block_resize(Monitor *mon, const QDict *qdict);
-- 
2.5.0