Re: [Qemu-devel] Adding throttling to virtio-9p

[Greg Kurz]

On Tue, 7 Jun 2016 10:20:51 +0200
Pradeep Kiruvale <address@hidden> wrote:
> Hi All,
> 
> I am trying to add the throttle to the virtio-9p devices using the throttle
> APIs that are already exists in the qemu.
> 
> I need help to understand the device model and where to add the throttling.
> I am digging through the code since a week or so but failed to understand
> how to tell the driver (virtio-9p) about the throttle enablement  for this
> specific fs device.
> 
> I am planning to enable and configure the throttle for that specific device
> at
> int qemu_fsdev_add(QemuOpts *opts) in qemu-fsdev.c file.
> 
> After that I would like to just add throttle facility to just
> virtio-9p-local.c (i.e read/wrote calls).
> Though there are other drivers, I just want to add to this specific driver
> as of now.
> 
> This is where I am missing the link like how to get to know the device
> configuration for this specific device throttle enabled or not and carry
> out the operations accordingly.
> 
> Please help me to understand.
> 

Drivers can register a parse_opts operation to handle specific command line
options. Since you want to make this feature specific to the local driver,
then you should handle the options in local_parse_opts(), not in 
qemu_fsdev_add().

> Regards,
> Pradeep

Cheers.

--
Greg