Re: [RFC PATCH 8/8] migration/dirtyrate: Implement qmp_cal_dirty_rate()/qmp_get_dirty_rate() function

[Eric Blake]

On 7/24/20 10:11 PM, Chuan Zheng wrote:
> From: Zheng Chuan <zhengchuan@huawei.com>
>
> Implement qmp_cal_dirty_rate()/qmp_get_dirty_rate() function which could be 
> called
> by libvirt api.
>
> Signed-off-by: Zheng Chuan <zhengchuan@huawei.com>
> Signed-off-by: YanYing Zhang <ann.zhuangyanying@huawei.com>
> ---

> +++ b/qapi/migration.json
> @@ -1621,3 +1621,27 @@
>   ##
>   { 'event': 'UNPLUG_PRIMARY',
>     'data': { 'device-id': 'str' } }
> +
> +##
> +# @cal_dirty_rate:

New QMP commands should be named favoring '-' over '_'; also, it doesn't 
hurt to spell it out:

calculate-dirty-rate

> +#
> +# start calculating dirty rate for vm
> +#
> +# @value: time for sample dirty pages

In what unit?

> +#
> +# Since: 5.1

We've missed 5.1; this will need to be updated to 5.2.

> +#
> +# Example:
> +#   {"command": "cal_dirty_rate", "data": {"value": 1} }
> +#
> +##
> +{ 'command': 'cal_dirty_rate', 'data': {'value': 'int64'} }
> +
> +##
> +# @get_dirty_rate:

get-dirty-rate, except that we tend to use 'query-' as the prefix for 
commands that read values.

> +#
> +# get dirty rate for vm
> +#
> +# Since: 5.1

5.2

What units is the rate expressed in?


> +##
> +{ 'command': 'get_dirty_rate', 'returns': 'int64' }
> diff --git a/qapi/pragma.json b/qapi/pragma.json
> index cffae27..ecd294b 100644
> --- a/qapi/pragma.json
> +++ b/qapi/pragma.json
> @@ -10,7 +10,8 @@
>           'query-migrate-cache-size',
>           'query-tpm-models',
>           'query-tpm-types',
> -        'ringbuf-read' ],
> +        'ringbuf-read',
> +        'get_dirty_rate' ],
>       'name-case-whitelist': [
>           'ACPISlotType',             # DIMM, visible through 
> query-acpi-ospm-status
>           'CpuInfoMIPS',              # PC, visible through query-cpu

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org