From mboxrd@z Thu Jan 1 00:00:00 1970 From: Don Dutile Subject: Re: [PATCH 2/7] Initial skeleton of VFIO support for Device Tree based devices Date: Tue, 29 Oct 2013 13:13:27 -0400 Message-ID: <526FECB7.9050904@redhat.com> References: <1380554923-17818-1-git-send-email-a.motakis@virtualopensystems.com> <1380554923-17818-3-git-send-email-a.motakis@virtualopensystems.com> <6A3DF150A5B70D4F9B66A25E3F7C888D0718A4AC@039-SN2MPN1-011.039d.mgd.msft.net> <526F0F7F.1040509@redhat.com> <1383047233.4097.124.camel@ul30vt.home> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1383047233.4097.124.camel-85EaTFmN5p//9pzu0YdTqQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Alex Williamson Cc: "linux-samsung-soc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "agraf-l3A5Bk7waGM@public.gmane.org" , Yoder Stuart-B08248 , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , Bhushan Bharat-R65777 , Antonios Motakis , "tech-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org" , "kvmarm-FPEHb7Xf0XXUo1n7N8X6UoWGPAHP3yOg@public.gmane.org" List-Id: iommu@lists.linux-foundation.org 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-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org [mailto:iommu- >>>> bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org] On Behalf Of Antonios Motakis >>>> Sent: Monday, September 30, 2013 8:59 PM >>>> To: kvmarm-FPEHb7Xf0XXUo1n7N8X6UoWGPAHP3yOg@public.gmane.org; alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org >>>> Cc: linux-samsung-soc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; agraf-l3A5Bk7waGM@public.gmane.org; Yoder >>>> Stuart-B08248; iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org; Antonios Motakis; >>>> tech-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org >>>> 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 >>>> --- >>>> 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. >>>> file mode 100644 index 0000000..b9686b0 >>>> --- /dev/null >>>> +++ b/drivers/vfio/vfio_platform.c >>>> @@ -0,0 +1,187 @@ >>>> +/* >>>> + * Copyright (C) 2013 - Virtual Open Systems >>>> + * Author: Antonios Motakis >>>> + * >>>> + * This program is free software; you can redistribute it and/or modify >>>> + * it under the terms of the GNU General Public License, version 2, as >>>> + * published by the Free Software Foundation. >>>> + * >>>> + * This program is distributed in the hope that it will be useful, >>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of >>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >>>> + * GNU General Public License for more details. >>>> + * >>>> + * You should have received a copy of the GNU General Public License >>>> + * along with this program; if not, write to the Free Software >>>> + * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. >>>> + */ >>>> + >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> +#include >>>> + >>>> +#define DRIVER_VERSION "0.1" >>>> +#define DRIVER_AUTHOR "Antonios Motakis" >>>> +#define DRIVER_DESC "VFIO Device Tree devices - User Level meta-driver" >>>> + >>>> +struct vfio_platform_device { >>>> + struct platform_device *pdev; >>>> +}; >>>> + >>>> +static void vfio_platform_release(void *device_data) { >>>> + module_put(THIS_MODULE); >>>> +} >>>> + >>>> +static int vfio_platform_open(void *device_data) { >>>> + if (!try_module_get(THIS_MODULE)) >>>> + return -ENODEV; >>>> + >>>> + return 0; >>>> +} >>>> + >>>> +static long vfio_platform_ioctl(void *device_data, >>>> + unsigned int cmd, unsigned long arg) { >>>> + 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 = VFIO_DEVICE_FLAGS_PLATFORM; >>>> + info.num_regions = 0; >>>> + info.num_irqs = 0; >>>> + >>>> + return copy_to_user((void __user *)arg,&info, minsz); >>>> + >>>> + } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) >>>> + return -EINVAL; >>>> + >>>> + else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) >>>> + return -EINVAL; >>>> + >>>> + else if (cmd == VFIO_DEVICE_SET_IRQS) >>>> + return -EINVAL; >>>> + >>>> + else if (cmd == VFIO_DEVICE_RESET) >>>> + return -EINVAL; >>>> + >>>> + return -ENOTTY; >>>> +} >>>> + >>>> +static ssize_t vfio_platform_read(void *device_data, char __user *buf, >>>> + size_t count, loff_t *ppos) >>>> +{ >>>> + return 0; >>>> +} >>>> + >>>> +static ssize_t vfio_platform_write(void *device_data, const char __user *buf, >>>> + size_t count, loff_t *ppos) >>>> +{ >>>> + return 0; >>>> +} >>>> + >>>> +static int vfio_platform_mmap(void *device_data, struct vm_area_struct >>>> +*vma) { >>>> + return -EINVAL; >>>> +} >>>> + >>>> +static const struct vfio_device_ops vfio_platform_ops = { >>>> + .name = "vfio-platform", >>>> + .open = vfio_platform_open, >>>> + .release = vfio_platform_release, >>>> + .ioctl = vfio_platform_ioctl, >>>> + .read = vfio_platform_read, >>>> + .write = vfio_platform_write, >>>> + .mmap = vfio_platform_mmap, >>>> +}; >>>> + >>>> +static int vfio_platform_probe(struct platform_device *pdev) { >>>> + struct vfio_platform_device *vdev; >>>> + struct iommu_group *group; >>>> + int ret; >>>> + >>>> + group = iommu_group_get(&pdev->dev); >>>> + if (!group) { >>>> + pr_err("VFIO: No IOMMU group for device %s\n", pdev->name); >>>> + return -EINVAL; >>>> + } >>>> + >>>> + vdev = kzalloc(sizeof(*vdev), GFP_KERNEL); >>>> + if (!vdev) { >>>> + iommu_group_put(group); >>>> + return -ENOMEM; >>>> + } >>>> + >>>> + vdev->pdev = pdev; >>>> + >>>> + ret = vfio_add_group_dev(&pdev->dev,&vfio_platform_ops, vdev); >>>> + if (ret) { >>>> + iommu_group_put(group); >>>> + kfree(vdev); >>>> + } >>>> + >>>> + return ret; >>>> +} >>>> + >>>> +static int vfio_platform_remove(struct platform_device *pdev) { >>>> + struct vfio_platform_device *vdev; >>>> + >>>> + vdev = vfio_del_group_dev(&pdev->dev); >>>> + if (!vdev) >>>> + return -EINVAL; >>>> + >>>> + iommu_group_put(pdev->dev.iommu_group); >>>> + kfree(vdev); >>>> + >>>> + return 0; >>>> +} >>>> + >>>> +static const struct of_device_id vfio_platform_match[] = { >>>> + /* Before this series can be applied, we shall implement a better >>>> + * mechanism to bind the module to any device. For now add the >>>> + * compatible property to the dtb of the devices we want to use. */ >>>> + { >>>> + .compatible = "vfio", >>>> + }, >>>> + {}, >>>> +}; >>>> +MODULE_DEVICE_TABLE(of, vfio_platform_match); >>>> + >>>> +static struct platform_driver vfio_platform_driver = { >>>> + .probe = vfio_platform_probe, >>>> + .remove = vfio_platform_remove, >>>> + .driver = { >>>> + .name = "vfio-platform", >>>> + .owner = THIS_MODULE, >>>> + .of_match_table = vfio_platform_match, >>>> + }, >>>> +}; >>>> + >>>> +module_platform_driver(vfio_platform_driver); >>>> + >>>> +MODULE_VERSION(DRIVER_VERSION); >>>> +MODULE_LICENSE("GPL v2"); >>>> +MODULE_AUTHOR(DRIVER_AUTHOR); >>>> +MODULE_DESCRIPTION(DRIVER_DESC); >>>> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index >>>> 284ff24..8d7434d 100644 >>>> --- a/include/uapi/linux/vfio.h >>>> +++ b/include/uapi/linux/vfio.h >>>> @@ -147,6 +147,7 @@ struct vfio_device_info { >>>> __u32 flags; >>>> #define VFIO_DEVICE_FLAGS_RESET (1<< 0) /* Device supports reset */ >>>> #define VFIO_DEVICE_FLAGS_PCI (1<< 1) /* vfio-pci device */ >>>> +#define VFIO_DEVICE_FLAGS_PLATFORM (1<< 2) /* vfio-platform device */ >>>> __u32 num_regions; /* Max region index + 1 */ >>>> __u32 num_irqs; /* Max IRQ index + 1 */ >>>> }; >>>> -- >>>> 1.8.1.2 >>>> >>>> _______________________________________________ >>>> iommu mailing list >>>> iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org >>>> https://lists.linuxfoundation.org/mailman/listinfo/iommu >>> >>> >>> _______________________________________________ >>> iommu mailing list >>> iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org >>> https://lists.linuxfoundation.org/mailman/listinfo/iommu >> >> -- >> To unsubscribe from this list: send the line "unsubscribe kvm" in >> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > >