[Qemu-devel] [PATCH v2 4/4] hmp: Add read-only option to change command

[Max Reitz <mreitz@redhat.com>]

Expose the new read-only option of 'blockdev-change-medium' for the
'change' HMP command.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 hmp-commands.hx | 20 +++++++++++++++++---
 hmp.c           | 21 ++++++++++++++++++++-
 2 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index e37bc8b..70cb7d7 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -196,8 +196,8 @@ ETEXI
 
     {
         .name       = "change",
-        .args_type  = "device:B,target:F,arg:s?",
-        .params     = "device filename [format]",
+        .args_type  = "device:B,target:F,arg:s?,read-only:s?",
+        .params     = "device filename [format [read-only]]",
         .help       = "change a removable medium, optional format",
         .mhandler.cmd = hmp_change,
     },
@@ -209,7 +209,7 @@ STEXI
 Change the configuration of a device.
 
 @table @option
-@item change @var{diskdevice} @var{filename} [@var{format}]
+@item change @var{diskdevice} @var{filename} [@var{format} [@var{read-only}]]
 Change the medium for a removable disk device to point to @var{filename}. eg
 
 @example
@@ -218,6 +218,20 @@ Change the medium for a removable disk device to point to @var{filename}. eg
 
 @var{format} is optional.
 
+@var{read-only} may be used to change the read-only status of the device. It
+accepts the following values:
+
+@table @var
+@item retain
+Retains the current status; this is the default.
+
+@item ro
+Makes the device read-only.
+
+@item rw
+Makes the device writable.
+@end table
+
 @item change vnc @var{display},@var{options}
 Change the configuration of the VNC server. The valid syntax for @var{display}
 and @var{options} are described at @ref{sec_invocation}. eg
diff --git a/hmp.c b/hmp.c
index 840da5c..f8769b9 100644
--- a/hmp.c
+++ b/hmp.c
@@ -23,6 +23,7 @@
 #include "monitor/monitor.h"
 #include "qapi/opts-visitor.h"
 #include "qapi/string-output-visitor.h"
+#include "qapi/util.h"
 #include "qapi-visit.h"
 #include "ui/console.h"
 #include "block/qapi.h"
@@ -1177,9 +1178,15 @@ void hmp_change(Monitor *mon, const QDict *qdict)
     const char *device = qdict_get_str(qdict, "device");
     const char *target = qdict_get_str(qdict, "target");
     const char *arg = qdict_get_try_str(qdict, "arg");
+    const char *read_only = qdict_get_try_str(qdict, "read-only");
+    BlockdevChangeReadOnlyMode read_only_mode = 0;
     Error *err = NULL;
 
     if (strcmp(device, "vnc") == 0) {
+        if (read_only) {
+            monitor_printf(mon, "Parameter 'read-only' is invalid for VNC");
+            return;
+        }
         if (strcmp(target, "passwd") == 0 ||
             strcmp(target, "password") == 0) {
             if (!arg) {
@@ -1189,7 +1196,19 @@ void hmp_change(Monitor *mon, const QDict *qdict)
         }
         qmp_change("vnc", target, !!arg, arg, &err);
     } else {
-        qmp_blockdev_change_medium(device, target, !!arg, arg, false, 0, &err);
+        if (read_only) {
+            read_only_mode =
+                qapi_enum_parse(BlockdevChangeReadOnlyMode_lookup,
+                                read_only, BLOCKDEV_CHANGE_READ_ONLY_MODE_MAX,
+                                BLOCKDEV_CHANGE_READ_ONLY_MODE_RETAIN, &err);
+            if (err) {
+                hmp_handle_error(mon, &err);
+                return;
+            }
+        }
+
+        qmp_blockdev_change_medium(device, target, !!arg, arg,
+                                   !!read_only, read_only_mode, &err);
         if (err &&
             error_get_class(err) == ERROR_CLASS_DEVICE_ENCRYPTED) {
             error_free(err);
-- 
1.9.3