Re: [Qemu-devel] [PATCH v6 3/4] kvm: add kvm_support_device() helper function

[Sergey Fedorov <serge.fdrv@gmail.com>]

On 23/03/16 17:56, Peter Xu wrote:
> On Wed, Mar 23, 2016 at 03:28:28PM +0300, Sergey Fedorov wrote:
>> On 23/03/16 08:32, Peter Xu wrote:
>>> diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
>>> index 6695fa7..8738fa1 100644
>>> --- a/include/sysemu/kvm.h
>>> +++ b/include/sysemu/kvm.h
>>> @@ -306,6 +306,15 @@ void kvm_device_access(int fd, int group, uint64_t attr,
>>>   */
>>>  int kvm_create_device(KVMState *s, uint64_t type, bool test);
>>>  
>>> +/**
>>> + * kvm_support_device - probe whether KVM support specific device
>>> + *
>>> + * @vmfd: The fd handler for VM
>>> + * @type: type of device
>>> + *
>>> + * @return: true if supported, otherwise false.
>>> + */
>>> +bool kvm_support_device(int vmfd, uint64_t type);
>> Why don't name the function like 'kvm_device_supported' to better express its predicative nature?
> Because I am trying to follow existing naming style, like:
> "kvm_create_device" (please see above).

Yes, but kvm_create_device() returns a file descriptor whereas this
function is predicative. Personally, I like the convention described in
chapter 16 of Linux kernel coding style [1]:

	If the name of a function is an action or an imperative command,
	the function should return an error-code integer.  If the name
	is a predicate, the function should return a "succeeded" boolean.


[1] https://www.kernel.org/doc/Documentation/CodingStyle

Kind regards,
Sergey