Re: [RFC PATCH] KVM: introduce kvm_check_device

[Scott Wood <scottwood@freescale.com>]

On Tue, 2015-01-06 at 16:12 +0000, Andre Przywara wrote:
> While we can easily register and unregister KVM devices, there is
> currently no easy way of checking whether a device has been
> registered.
> Introduce kvm_check_device() for that purpose and use it in two
> existing functions. Also change the return code for an invalid
> type number from ENOSPC to EINVAL.
> This function will be later used by another patch set to check
> whether a KVM_CREATE_IRQCHIP ioctl is valid.

You're checking whether a device type has been registered, not the
device itself -- so could you make it kvm_check_device_type()?

> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
> Hi,
> 
> can people comment whether there is an easier way to detect KVM
> device registration _outside_ of virt/kvm/kvm_main.c? Using the
> KVM_CREATE_DEVICE_TEST flag sounds like a fit, but
> kvm_ioctl_create_device() isn't exported.

Out of curiosity, why do you need to test it from inside the kernel but
outside kvm_main.c?

-Scott