Applying Throttle Block Filter via QMP Command

[Henry lol]

Hello,

I want to apply a throttle block filter using the QMP command, but it
doesn't seem to work as the I/O performance remains the same.

Are there any additional steps I need to follow?
I predefined the throttle-group object and block device in the QEMU
parameters and then used the blockdev-add QMP command to apply the
filter, as described in the link
- https://github.com/qemu/qemu/blob/master/docs/throttle.txt#L315-L322

Additionally, I’ve confirmed that the filter works well when defined
in the QEMU -drive parameter instead of using the QMP command.

thanks,