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

[Pavel Hrdina <phrdina@redhat.com>]

On 07/12/2012 07:53 PM, Eric Blake wrote:
> 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'.)
This sounds reasonable and I think that this could be also good for HMP, 
not only for QMP.
If there isn't anyone who disagree, I'll implement it.

Pavel
>> +#
>> +# 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'?
>