blockdev: read-only-mode for blockdev-change-medium
Add an option to qmp_blockdev_change_medium() which allows changing the
read-only status of the block device whose medium is changed.
Some drives do not have a inherently fixed read-only status; for
instance, floppy disks can be set read-only or writable independently of
the drive. Some users may find it useful to be able to therefore change
the read-only status of a block device when changing the medium.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/qmp-commands.hx b/qmp-commands.hx
index f6d9c25..39d6e25 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -4183,7 +4183,7 @@
{
.name = "blockdev-change-medium",
- .args_type = "device:B,filename:F,format:s?",
+ .args_type = "device:B,filename:F,format:s?,read-only-mode:s?",
.mhandler.cmd_new = qmp_marshal_blockdev_change_medium,
},
@@ -4199,6 +4199,8 @@
- "device": device name (json-string)
- "filename": filename of the new image (json-string)
- "format": format of the new image (json-string, optional)
+- "read-only-mode": new read-only mode (json-string, optional)
+ - Possible values: "retain" (default), "read-only", "read-write"
Examples:
@@ -4210,6 +4212,26 @@
"format": "raw" } }
<- { "return": {} }
+2. Load a read-only medium into a writable drive
+
+-> { "execute": "blockdev-change-medium",
+ "arguments": { "device": "isa-fd0",
+ "filename": "/srv/images/ro.img",
+ "format": "raw",
+ "read-only-mode": "retain" } }
+
+<- { "error":
+ { "class": "GenericError",
+ "desc": "Could not open '/srv/images/ro.img': Permission denied" } }
+
+-> { "execute": "blockdev-change-medium",
+ "arguments": { "device": "isa-fd0",
+ "filename": "/srv/images/ro.img",
+ "format": "raw",
+ "read-only-mode": "read-only" } }
+
+<- { "return": {} }
+
EQMP
{
