[PATCH 2/3] Initial skeleton of VFIO support for Device Tree based devices
Mark Rutland
mark.rutland at arm.com
Mon Aug 5 09:37:58 EDT 2013
[adding DT maintainers to Cc]
On Mon, Aug 05, 2013 at 02:17:11PM +0100, Antonios Motakis wrote:
> 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 at virtualopensystems.com>
> ---
> drivers/vfio/Kconfig | 10 +++
> drivers/vfio/Makefile | 1 +
> drivers/vfio/vfio_dt.c | 187 ++++++++++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/vfio.h | 1 +
> 4 files changed, 199 insertions(+)
> create mode 100644 drivers/vfio/vfio_dt.c
>
> diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
> index 1f84eda..a77a2e4 100644
> --- a/drivers/vfio/Kconfig
> +++ b/drivers/vfio/Kconfig
> @@ -13,4 +13,14 @@ menuconfig VFIO
>
> If you don't know what to do here, say N.
>
> +config VFIO_DT
> + tristate "VFIO support for Device Tree devices"
> + depends on VFIO && EVENTFD
> + help
> + Support for the VFIO Device Tree driver. This is required to make
> + use of platform devices present on Device Tree nodes using the VFIO
> + framework.
> +
> + 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..d599a67 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_DT) += vfio_dt.o
> diff --git a/drivers/vfio/vfio_dt.c b/drivers/vfio/vfio_dt.c
> new file mode 100644
> index 0000000..ad4d31d
> --- /dev/null
> +++ b/drivers/vfio/vfio_dt.c
> @@ -0,0 +1,187 @@
> +/*
> + * Copyright (C) 2013 - Virtual Open Systems
> + * Author: Antonios Motakis <a.motakis at virtualopensystems.com>
> + *
> + * 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 <linux/device.h>
> +#include <linux/eventfd.h>
> +#include <linux/interrupt.h>
> +#include <linux/iommu.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/notifier.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +#include <linux/uaccess.h>
> +#include <linux/vfio.h>
> +
> +#define DRIVER_VERSION "0.1"
> +#define DRIVER_AUTHOR "Antonios Motakis <a.motakis at virtualopensystems.com>"
> +#define DRIVER_DESC "VFIO Device Tree devices - User Level meta-driver"
> +
> +struct vfio_dt_device {
> + struct platform_device *pdev;
> +};
> +
> +static void vfio_dt_release(void *device_data)
> +{
> + module_put(THIS_MODULE);
> +}
> +
> +static int vfio_dt_open(void *device_data)
> +{
> + if (!try_module_get(THIS_MODULE))
> + return -ENODEV;
> +
> + return 0;
> +}
> +
> +static long vfio_dt_ioctl(void *device_data,
> + unsigned int cmd, unsigned long arg)
> +{
> + struct vfio_dt_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_DT;
> + 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_dt_read(void *device_data, char __user *buf,
> + size_t count, loff_t *ppos)
> +{
> + return 0;
> +}
> +
> +static ssize_t vfio_dt_write(void *device_data, const char __user *buf,
> + size_t count, loff_t *ppos)
> +{
> + return 0;
> +}
> +
> +static int vfio_dt_mmap(void *device_data, struct vm_area_struct *vma)
> +{
> + return -EINVAL;
> +}
> +
> +static const struct vfio_device_ops vfio_dt_ops = {
> + .name = "vfio-dts",
> + .open = vfio_dt_open,
> + .release = vfio_dt_release,
> + .ioctl = vfio_dt_ioctl,
> + .read = vfio_dt_read,
> + .write = vfio_dt_write,
> + .mmap = vfio_dt_mmap,
> +};
> +
> +static int vfio_dt_probe(struct platform_device *pdev)
> +{
> + struct vfio_dt_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_dt_ops, vdev);
> + if (ret) {
> + iommu_group_put(group);
> + kfree(vdev);
> + }
> +
> + return ret;
> +}
> +
> +static int vfio_dt_remove(struct platform_device *pdev)
> +{
> + struct vfio_dt_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_dt_match[] = {
> + /* In the future, we can 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-dt",
> + },
> + {},
> +};
This definitely doesn't belong in the dt. It's purely a Linux
abstraction and does not represent a piece of hardware or common
interface.
We need to think of a better mechanism for binding the module to these
devices now.
Thanks,
Mark.
> +MODULE_DEVICE_TABLE(of, vfio_dt_match);
> +
> +static struct platform_driver vfio_dt_driver = {
> + .probe = vfio_dt_probe,
> + .remove = vfio_dt_remove,
> + .driver = {
> + .name = "vfio-dt",
> + .owner = THIS_MODULE,
> + .of_match_table = vfio_dt_match,
> + },
> +};
> +
> +module_platform_driver(vfio_dt_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..1e4bef2 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_DT (1 << 2) /* vfio-dt device */
> __u32 num_regions; /* Max region index + 1 */
> __u32 num_irqs; /* Max IRQ index + 1 */
> };
> --
> 1.8.1.2
>
>
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