> -----Original Message----- > From: Don Dutile [mailto:ddutile@xxxxxxxxxx] > Sent: Tuesday, October 29, 2013 12:13 PM > To: Alex Williamson > Cc: Bhushan Bharat-R65777; Antonios Motakis; > kvmarm@xxxxxxxxxxxxxxxxxxxxx; linux-samsung-soc@xxxxxxxxxxxxxxx; > kvm@xxxxxxxxxxxxxxx; agraf@xxxxxxx; Yoder Stuart-B08248; > iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; tech@xxxxxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH 2/7] Initial skeleton of VFIO support for Device Tree > based devices > > On 10/29/2013 07:47 AM, Alex Williamson wrote: > > On Mon, 2013-10-28 at 21:29 -0400, Don Dutile wrote: > >> On 09/30/2013 11:37 AM, Bhushan Bharat-R65777 wrote: > >>> > >>> > >>>> -----Original Message----- > >>>> From: iommu-bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx [mailto:iommu- > >>>> bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx] On Behalf Of Antonios Motakis > >>>> Sent: Monday, September 30, 2013 8:59 PM > >>>> To: kvmarm@xxxxxxxxxxxxxxxxxxxxx; alex.williamson@xxxxxxxxxx > >>>> Cc: linux-samsung-soc@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; > agraf@xxxxxxx; Yoder > >>>> Stuart-B08248; iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; Antonios Motakis; > >>>> tech@xxxxxxxxxxxxxxxxxxxxxx > >>>> Subject: [PATCH 2/7] Initial skeleton of VFIO support for Device > Tree based > >>>> devices > >>>> > >>>> Platform devices in the Linux kernel are usually managed by the DT > interface. > >>>> This patch forms the base to support these kind of devices with > VFIO. > >>>> > >>>> Signed-off-by: Antonios Motakis<a.motakis@xxxxxxxxxxxxxxxxxxxxxx> > >>>> --- > >>>> drivers/vfio/Kconfig | 11 +++ > >>>> drivers/vfio/Makefile | 1 + > >>>> drivers/vfio/vfio_platform.c | 187 > +++++++++++++++++++++++++++++++++++++++++++ > >>>> include/uapi/linux/vfio.h | 1 + > >>>> 4 files changed, 200 insertions(+) > >>>> create mode 100644 drivers/vfio/vfio_platform.c > >>>> > >>>> diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig index > 1f84eda..35254b7 > >>>> 100644 > >>>> --- a/drivers/vfio/Kconfig > >>>> +++ b/drivers/vfio/Kconfig > >>>> @@ -13,4 +13,15 @@ menuconfig VFIO > >>>> > >>>> If you don't know what to do here, say N. > >>>> > >>>> +config VFIO_PLATFORM > >>>> + tristate "VFIO support for device tree based platform > devices" > >>>> + depends on VFIO&& EVENTFD&& OF > >>>> + help > >>>> + Support for platform devices with VFIO. This is required to > make > >>>> + use of platform devices present on device tree nodes using > the VFIO > >>>> + framework. Devices that are not described in the device > tree cannot > >>>> + be used by this driver. > >>>> + > >>>> + If you don't know what to do here, say N. > >>>> + > >>>> source "drivers/vfio/pci/Kconfig" > >>>> diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile index > >>>> 2398d4a..575c8dd 100644 > >>>> --- a/drivers/vfio/Makefile > >>>> +++ b/drivers/vfio/Makefile > >>>> @@ -1,3 +1,4 @@ > >>>> obj-$(CONFIG_VFIO) += vfio.o > >>>> obj-$(CONFIG_VFIO_IOMMU_TYPE1) += vfio_iommu_type1.o > >>>> obj-$(CONFIG_VFIO_PCI) += pci/ > >>>> +obj-$(CONFIG_VFIO_PLATFORM) += vfio_platform.o > >>>> diff --git a/drivers/vfio/vfio_platform.c > b/drivers/vfio/vfio_platform.c new > >>> > >>> We can make this parallel to PCI, something like > drivers/vfio/platform/platform.c > >>> > >> pls, no. 'platform' is too generic, and it really means 'arm-dt' ... > so can > >> move it to the arch/arm space, and have it's kconfig conditional on > ARM&&VFIO. > >> if kept under drivers/vfio, then use a better directory name that ties > it to arm-dt. > >> thanks. > > > > The intention is that vfio platform device support is not arm-dt > > specific. This is to be used by both arm and embedded ppc. The > devices > > we intend to support with them are known as platform drivers in the > > kernel, thus the name. I suppose the question remains whether the > > interface here is really generic for any "platform" device or whether > > we're making whether we're making an interface specifically for device > > tree platform devices, or if those are one in the same. In any case, > > arm-dt is certainly not the answer. > > > > Alex > > > I thought that was the intention until I saw this use in platform.c: > static const struct of_device_id vfio_platform_match[] = { > > So, of_device_id hit me as DT-specific, and thus, the file should have > a name that implies its not as platform-generic as one may want/expect. > I agree that the 'arm' part can be dropped, but it's not of-agnostic atm. That part of the patch needs to be re-worked...and the comment indicates it is not final. The vfio-platform driver should not register to handle specific compatible strings. Kim Phillips has a patch posted that adds 'wildcard' support to platform drivers so that a driver can bind to any device. Stuart -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
