Re: [Qemu-devel] [RFC PATCH 1/4] qapi: Convert savevm

[Eric Blake <eblake@redhat.com>]

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On 07/12/2012 10:55 AM, Pavel Hrdina wrote:
> Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
> ---

> +++ b/qapi-schema.json
> @@ -1868,3 +1868,25 @@
>  # Since: 0.14.0
>  ##
>  { 'command': 'netdev_del', 'data': {'id': 'str'} }
> +
> +##
> +# @savevm:
> +#
> +# Create a snapshot of the whole virtual machine. If 'tag' is provided,
> +# it is used as human readable identifier. If there is already a snapshot
> +# with the same tag or ID, it is replaced.
> +#
> +# @name: tag or id of new or existing snapshot

Needs an #optional designation, given the syntax below.

> +#
> +# Returns: Nothing on success
> +#          If there is a writable device not supporting snapshots,
> +#            SnapshotNotSupported
> +#          If no block device can accept snapshots, SnapshotNotAccepted
> +#          If an error occures while creating a snapshot, SnapshotCreateFailed

s/occures/occurs/

> +#          If open a block device for vm state fail, SnapshotOpenFailed
> +#          If an error uccures while writing vm state, SnapshotWriteFailed

s/uccures/occurs/

> +#          If delete snapshot with same 'name' fail, SnapshotDeleteFailed

The notion of blindly overwriting the existing snapshot of the same name
seems a bit dangerous; should we take this opportunity to enhance the
command, and add a force flag, where things fail if the flag is false
but the name already exists, and where the reuse only happens if the
flag is present?  (In fact, it would make my life in libvirt easier, as
I have an action item to make libvirt reject attempts to create a
snapshot with tag named '1' if an existing snapshot already has an id of
'1'.)

> +#
> +# Since: 1.2
> +##
> +{ 'command': 'savevm', 'data': {'*name': 'str'} }
> \ No newline at end of file

Fix that.

> @@ -1061,6 +1061,32 @@ Example:
>  
>  EQMP
>      {
> +        .name       = "savevm",
> +        .args_type  = "name:s?",
> +        .params     = "name",
> +        .help       = "save a VM snapshot. If no tag or id are provided, a new snapshot is created",
> +        .mhandler.cmd_new = qmp_marshal_input_savevm
> +    },
> +
> +SQMP
> +savevm

I know the HMP command is short, for ease of typing; but since 'savevm'
is not an English word, should we name the QMP command 'save-vm'?

-- 
Eric Blake   eblake@redhat.com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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