Re: [Qemu-devel] [PATCH] Introduce "xen-load-devices-state"

[Changlong Xie <xiecl.fnst@cn.fujitsu.com>]

On 03/11/2016 04:31 AM, Eric Blake wrote:
> On 03/10/2016 03:23 AM, Changlong Xie wrote:
>> From: Wen Congyang <wency@cn.fujitsu.com>
>>
>> Introduce a "xen-load-devices-state" QAPI command that can be used to load
>> the state of all devices, but not the RAM or the block devices of the
>> VM.
>>
>> We only have hmp commands savevm/loadvm, and qmp commands
>> xen-save-devices-state.
>>
>> We use this new command for COLO:
>> 1. suspend both primay vm and secondary vm
>
> s/primay/primary/

Hi Eric

Will fix in next version.

>
>> 2. sync the state
>> 3. resume both primary vm and secondary vm
>>
>> In such case, we need to update all devices's state in any time.
>
> s/devices's/devices/'

Ditto.

>
>>
>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>> Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
>> ---
>
>> +++ b/qapi-schema.json
>> @@ -4122,3 +4122,21 @@
>>   ##
>>   { 'enum': 'ReplayMode',
>>     'data': [ 'none', 'record', 'play' ] }
>> +
>> +##
>> +# @xen-load-devices-state:
>> +#
>> +# Load the state of all devices from file. The RAM and the block devices
>> +# of the VM are not loaded by this command.
>> +#
>> +# @filename: the file to load the state of the devices from as binary
>> +# data. See xen-save-devices-state.txt for a description of the binary
>> +# format.
>> +#
>> +# Returns: Nothing on success
>> +#          If @filename cannot be opened, OpenFileFailed
>> +#          If an I/O error occurs while reading the file, IOError
>
> Drop the whole Returns: paragraph.  We have very few distinguished error
> categories, and you are not using anything other than a generic error
> category here (that is, OpenFileFailed and IOError are NOT valid QMP
> error categories).
>

Ditto.

>> +#
>> +# Since: 2.6
>
> You missed soft freeze; is this still 2.6 material?
>

"Since: 2.7" should be fine.

>
>> +++ b/qmp-commands.hx
>> @@ -587,6 +587,33 @@ Example:
>>   EQMP
>>
>>       {
>> +        .name       = "xen-load-devices-state",
>> +        .args_type  = "filename:F",
>> +        .mhandler.cmd_new = qmp_marshal_xen_load_devices_state,
>> +    },
>> +
>> +SQMP
>> +xen-load-devices-state
>> +-------
>
> Make the ---- separator line the same length as the text it is underlining.
>

Surely.

Thanks
	-Xie