From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:35962)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <serge.fdrv@gmail.com>) id 1aikJx-0005cx-RW
	for qemu-devel@nongnu.org; Wed, 23 Mar 2016 11:03:42 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <serge.fdrv@gmail.com>) id 1aikJw-0003IQ-UJ
	for qemu-devel@nongnu.org; Wed, 23 Mar 2016 11:03:41 -0400
References: <1458711153-15988-1-git-send-email-peterx@redhat.com>
	<1458711153-15988-4-git-send-email-peterx@redhat.com>
	<56F28BEC.2070008@gmail.com> <20160323145652.GW28183@pxdev.xzpeter.org>
From: Sergey Fedorov <serge.fdrv@gmail.com>
Message-ID: <56F2B044.4030202@gmail.com>
Date: Wed, 23 Mar 2016 18:03:32 +0300
MIME-Version: 1.0
In-Reply-To: <20160323145652.GW28183@pxdev.xzpeter.org>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH v6 3/4] kvm: add kvm_support_device()
 helper function
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Peter Xu <peterx@redhat.com>
Cc: wei@redhat.com, peter.maydell@linaro.org, drjones@redhat.com, libvir-list@redhat.com, armbru@redhat.com, qemu-devel@nongnu.org, mdroth@linux.vnet.ibm.com, qemu-arm@nongnu.org, abologna@redhat.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