What static=on really does is what we call metadata preallocation for
other block drivers. While we can still change the QMP interface, make
it more consistent by using 'preallocation' for VDI, too.

This doesn't implement any new functionality, so the only supported
preallocation modes are 'off' and 'metadata' for now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qapi/block-core.json |  6 ++----
 block/vdi.c          | 24 ++++++++++++++++++++++--
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index 5b0ad1a8b7..f6673f2b13 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -3834,16 +3834,14 @@
 #
 # @file             Node to create the image format on
 # @size             Size of the virtual disk in bytes
-# @static           Whether to create a statically (true) or
-#                   dynamically (false) allocated image
-#                   (default: false, i.e. dynamic)
+# @preallocation    Preallocation mode for the new image (default: off)
 #
 # Since: 2.12
 ##
 { 'struct': 'BlockdevCreateOptionsVdi',
   'data': { 'file':             'BlockdevRef',
             'size':             'size',
-            '*static':          'bool' } }
+            '*preallocation':   'PreallocMode' } }
 
 ##
 # @BlockdevVhdxSubformat:
diff --git a/block/vdi.c b/block/vdi.c
index d939b034c4..73c059e69d 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -728,7 +728,7 @@ static int coroutine_fn vdi_co_do_create(BlockdevCreateOptions *create_options,
     int ret = 0;
     uint64_t bytes = 0;
     uint32_t blocks;
-    uint32_t image_type = VDI_TYPE_DYNAMIC;
+    uint32_t image_type;
     VdiHeader header;
     size_t i;
     size_t bmap_size;
@@ -744,9 +744,22 @@ static int coroutine_fn vdi_co_do_create(BlockdevCreateOptions *create_options,
 
     /* Validate options and set default values */
     bytes = vdi_opts->size;
-    if (vdi_opts->q_static) {
+
+    if (!vdi_opts->has_preallocation) {
+        vdi_opts->preallocation = PREALLOC_MODE_OFF;
+    }
+    switch (vdi_opts->preallocation) {
+    case PREALLOC_MODE_OFF:
+        image_type = VDI_TYPE_DYNAMIC;
+        break;
+    case PREALLOC_MODE_METADATA:
         image_type = VDI_TYPE_STATIC;
+        break;
+    default:
+        error_setg(errp, "Preallocation mode not supported for vdi");
+        return -EINVAL;
     }
+
 #ifndef CONFIG_VDI_STATIC_IMAGE
     if (image_type == VDI_TYPE_STATIC) {
         ret = -ENOTSUP;
@@ -874,6 +887,7 @@ static int coroutine_fn vdi_co_create_opts(const char *filename, QemuOpts *opts,
     BlockdevCreateOptions *create_options = NULL;
     BlockDriverState *bs_file = NULL;
     uint64_t block_size = DEFAULT_CLUSTER_SIZE;
+    bool is_static = false;
     Visitor *v;
     Error *local_err = NULL;
     int ret;
@@ -895,6 +909,9 @@ static int coroutine_fn vdi_co_create_opts(const char *filename, QemuOpts *opts,
         goto done;
     }
 #endif
+    if (qemu_opt_get_bool_del(opts, BLOCK_OPT_STATIC, false)) {
+        is_static = true;
+    }
 
     qdict = qemu_opts_to_qdict_filtered(opts, NULL, &vdi_create_opts, true);
 
@@ -913,6 +930,9 @@ static int coroutine_fn vdi_co_create_opts(const char *filename, QemuOpts *opts,
 
     qdict_put_str(qdict, "driver", "vdi");
     qdict_put_str(qdict, "file", bs_file->node_name);
+    if (is_static) {
+        qdict_put_str(qdict, "preallocation", "metadata");
+    }
 
     /* Get the QAPI object */
     v = qobject_input_visitor_new_keyval(QOBJECT(qdict));
-- 
2.13.6

On 03/20/2018 12:36 PM, Kevin Wolf wrote:
> What static=on really does is what we call metadata preallocation for
> other block drivers. While we can still change the QMP interface, make
> it more consistent by using 'preallocation' for VDI, too.

The x- naming of the command means we don't HAVE to get this patch in 
for 2.12, but I agree that sooner is better than later and that doing 
this in 2.12 is worth the effort.

> 
> This doesn't implement any new functionality, so the only supported
> preallocation modes are 'off' and 'metadata' for now.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>   qapi/block-core.json |  6 ++----
>   block/vdi.c          | 24 ++++++++++++++++++++++--
>   2 files changed, 24 insertions(+), 6 deletions(-)
> 

> +++ b/qapi/block-core.json
> @@ -3834,16 +3834,14 @@
>   #
>   # @file             Node to create the image format on
>   # @size             Size of the virtual disk in bytes
> -# @static           Whether to create a statically (true) or
> -#                   dynamically (false) allocated image
> -#                   (default: false, i.e. dynamic)
> +# @preallocation    Preallocation mode for the new image (default: off)

Do we want to document that 'full' is not supported yet?  Or is just 
relying on the error message good enough?

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org