Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757322AbaKTO13 (ORCPT ); Thu, 20 Nov 2014 09:27:29 -0500 Received: from mail-wg0-f46.google.com ([74.125.82.46]:58525 "EHLO mail-wg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756498AbaKTO11 (ORCPT ); Thu, 20 Nov 2014 09:27:27 -0500 Message-ID: <546DFA04.9060901@linaro.org> Date: Thu, 20 Nov 2014 15:26:12 +0100 From: Eric Auger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Antonios Motakis , Alex Williamson CC: kvm-arm , Linux IOMMU , Will Deacon , VirtualOpenSystems Technical Team , Christoffer Dall , Kim Phillips , Marc Zyngier , VFIO DRIVER , open list Subject: Re: [PATCH v9 06/19] vfio/platform: return info for bound device References: <1414433284-31719-1-git-send-email-a.motakis@virtualopensystems.com> <1414433284-31719-7-git-send-email-a.motakis@virtualopensystems.com> <5463373C.2010202@linaro.org> <1415810168.16601.353.camel@ul30vt.home> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/20/2014 03:10 PM, Antonios Motakis wrote: > On Wed, Nov 12, 2014 at 5:36 PM, Alex Williamson > wrote: >> On Wed, 2014-11-12 at 11:32 +0100, Eric Auger wrote: >>> On 10/27/2014 07:07 PM, Antonios Motakis wrote: >>>> A VFIO userspace driver will start by opening the VFIO device >>>> that corresponds to an IOMMU group, and will use the ioctl interface >>>> to get the basic device info, such as number of memory regions and >>>> interrupts, and their properties. This patch enables the >>>> VFIO_DEVICE_GET_INFO ioctl call. >>>> >>>> Signed-off-by: Antonios Motakis >>>> --- >>>> drivers/vfio/platform/vfio_platform_common.c | 23 ++++++++++++++++++++--- >>>> 1 file changed, 20 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c >>>> index e0fdbc8..cb20526 100644 >>>> --- a/drivers/vfio/platform/vfio_platform_common.c >>>> +++ b/drivers/vfio/platform/vfio_platform_common.c >>>> @@ -43,10 +43,27 @@ static int vfio_platform_open(void *device_data) >>>> static long vfio_platform_ioctl(void *device_data, >>>> unsigned int cmd, unsigned long arg) >>>> { >>>> - if (cmd == VFIO_DEVICE_GET_INFO) >>>> - return -EINVAL; >>>> + struct vfio_platform_device *vdev = device_data; >>>> + unsigned long minsz; >>>> + >>>> + if (cmd == VFIO_DEVICE_GET_INFO) { >>>> + struct vfio_device_info info; >>>> + >>>> + minsz = offsetofend(struct vfio_device_info, num_irqs); >>>> + >>>> + if (copy_from_user(&info, (void __user *)arg, minsz)) >>>> + return -EFAULT; >>>> + >>>> + if (info.argsz < minsz) >>>> + return -EINVAL; >>>> + >>>> + info.flags = vdev->flags; >>>> + info.num_regions = 0; >>>> + info.num_irqs = 0; >>> Seems a bit weird to me to enable the modality but returning zeroed >>> values. Shouldn't we put that patch after VFIO_DEVICE_GET_REGION_INFO >>> and VFIO_DEVICE_GET_IRQ_INFO ones? >> >> I actually like how Antonios has started from a base framework, exposing >> a device but none of the resources and then incrementally adds each >> component. It's also a good showcase of the VFIO ABI that we can do >> things like this. Thanks, > > I also agree with Alex with this. But of course I'm not married with > any particular splitting style, in case we decide to change this. Hi Antonios, please keep as is. I also learn each day about splitting style ;-) Best Regards Eric > >> >> Alex >> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/