Re: [PATCH v2 15/15] Drivers: hv: Add modules to expose /dev/mshv to VMMs running on Hyper-V

[Boqun Feng]

On Thu, Aug 17, 2023 at 03:01:51PM -0700, Nuno Das Neves wrote:
[...]
> +static long
> +mshv_dev_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
> +{
> +	switch (ioctl) {
> +	case MSHV_CHECK_EXTENSION:
> +		return mshv_ioctl_check_extension((void __user *)arg);
> +	case MSHV_CREATE_PARTITION:
> +		return mshv.create_partition((void __user *)arg);
> +	case MSHV_CREATE_VTL:
> +		return mshv.create_vtl((void __user *)arg);
> +	}
> +

Shouldn't we also have a MSHV_GET_API_VERSION ioctl similar as KVM? So
that in the future when we change these ioctl interfaces or semantics,
we can bump up the API version to avoid breaking userspace?

Regards,
Boqun