Re: [PATCH RFC v3 05/16] qemu: monitor: Add support for ThrottleGroup operations
On Wed, Aug 07, 2024 at 12:07:26 +0800, Chun Feng Wu wrote:
Please do not top-post on technical lists. Put your reply inline with
the relevant context.
let me confirm my understanding, do you mean there should be group
name
mapping between DOM($group_name_in_DOM) and QOM(throttle-$group_name_in_DOM)
for both throttle group and throttle filter? if so, there seems two ways to
achieve that:
The main point is that the throttle group names are arbitrary, we must
ensure that the user won't pick a name that collides with any other QOM
name or for that matter for any thing else.
There are multiple ways how to achieve that, but the easiest seems to
add a prefix and sanitize the name to e.g contain only characters and
numbers. Others like numbering them arbitrarily or so seem to be too
much hassle.
For the -blockdev throttle naming they should use existing node name
generators and not be based on anything user provided. Node-names are
length-limited so users might pick a name that'd exceed the limit. Thus
not allowing any control is the best there.
- mapping group_name in callers like qemu_driver.c, qemu_hotplug.c,
qemu_command.c
- or put all mappings only into qemu_monitor.c/qemu_monitor_json.c, in this
way, I may need to expose more methods within monitor to prepare
virJSONValueObject for ThrottleGroup and ThrottleFilter creation, it seems
this way can centralize mapping logic within monitor only
It can't be limited to monitor, because you need to construct the
trhottling '-object' also when starting up qemu. So it needs to apply
wherever appropriate.
As the prefix is constant you don't need any helpers or extra infra to
decorate it. Just add it where appropriate.
On 2024/7/26 21:58, Peter Krempa wrote:
> Note that since all objects live in one namespace in qemu you'll have to
> add a prefix to the group name so that the user will not be able to
> accidentaly pick a group name (which would be equivalent with the object
> 'id') which we might either be using or introduce in the future.
>
> Add a 'throttle-' prefix so that we clearly separate the throttle group
> objects into their own namespace.
>
> This will need to be done everywhere where you pass the throttle group
> name as object name to qemu.
--
Thanks and Regards,
Wu