Re: [RFC PATCH v5 05/11] VFIO_PLATFORM: Initial skeleton of VFIO support for platform devices

From: Antonios Motakis
Date: Tue Apr 29 2014 - 09:23:31 EST

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In reply to: Antonios Motakis: "[RFC PATCH v5 05/11] VFIO_PLATFORM: Initial skeleton of VFIO support for platform devices"
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On Mon, Apr 28, 2014 at 7:04 PM, Alex Williamson
<alex.williamson@xxxxxxxxxx> wrote:
> On Mon, 2014-04-28 at 17:52 +0200, Antonios Motakis wrote:
>> This patch forms the skeleton for platform devices support with VFIO.
>>
>> Signed-off-by: Antonios Motakis <a.motakis@xxxxxxxxxxxxxxxxxxxxxx>
>> ---
>> drivers/vfio/Kconfig | 1 +
>> drivers/vfio/Makefile | 1 +
>> drivers/vfio/platform/Kconfig | 9 ++
>> drivers/vfio/platform/Makefile | 4 +
>> drivers/vfio/platform/vfio_platform.c | 172 ++++++++++++++++++++++++++
>> drivers/vfio/platform/vfio_platform_private.h | 22 ++++
>> include/uapi/linux/vfio.h | 1 +
>> 7 files changed, 210 insertions(+)
>> create mode 100644 drivers/vfio/platform/Kconfig
>> create mode 100644 drivers/vfio/platform/Makefile
>> create mode 100644 drivers/vfio/platform/vfio_platform.c
>> create mode 100644 drivers/vfio/platform/vfio_platform_private.h
>>
>> diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
>> index 3a598ed..a484d72 100644
>> --- a/drivers/vfio/Kconfig
>> +++ b/drivers/vfio/Kconfig
>> @@ -21,3 +21,4 @@ menuconfig VFIO
>> If you don't know what to do here, say N.
>>
>> source "drivers/vfio/pci/Kconfig"
>> +source "drivers/vfio/platform/Kconfig"
>> diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile
>> index 72bfabc..b5e4a33 100644
>> --- a/drivers/vfio/Makefile
>> +++ b/drivers/vfio/Makefile
>> @@ -2,3 +2,4 @@ obj-$(CONFIG_VFIO) += vfio.o
>> obj-$(CONFIG_VFIO_IOMMU_TYPE1) += vfio_iommu_type1.o
>> obj-$(CONFIG_VFIO_IOMMU_SPAPR_TCE) += vfio_iommu_spapr_tce.o
>> obj-$(CONFIG_VFIO_PCI) += pci/
>> +obj-$(CONFIG_VFIO_PLATFORM) += platform/
>> diff --git a/drivers/vfio/platform/Kconfig b/drivers/vfio/platform/Kconfig
>> new file mode 100644
>> index 0000000..42b0022
>> --- /dev/null
>> +++ b/drivers/vfio/platform/Kconfig
>> @@ -0,0 +1,9 @@
>> +config VFIO_PLATFORM
>> + tristate "VFIO support for platform devices"
>> + depends on VFIO && EVENTFD
>
> VFIO_PCI also depends on PCI, is there no CONFIG_PLATFORM? What benefit
> would I get from this if I enable it on my x86 box?

That's a good point. Unfortunately I don't know of an obvious config
we can depend on, other than known target platforms (i.e. ARM).

Useless on an x86 PC, but maybe someone has a weird x86 based non-PC
based architecture somewhere :)

>
>> + help
>> + Support for platform devices with VFIO. This is required to make
>> + use of platform devices present on the system using the VFIO
>> + framework.
>> +
>> + If you don't know what to do here, say N.
>> diff --git a/drivers/vfio/platform/Makefile b/drivers/vfio/platform/Makefile
>> new file mode 100644
>> index 0000000..df3a014
>> --- /dev/null
>> +++ b/drivers/vfio/platform/Makefile
>> @@ -0,0 +1,4 @@
>> +
>> +vfio-platform-y := vfio_platform.o
>> +
>> +obj-$(CONFIG_VFIO_PLATFORM) += vfio-platform.o
>> diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c
>> new file mode 100644
>> index 0000000..1661746
>> --- /dev/null
>> +++ b/drivers/vfio/platform/vfio_platform.c
>> @@ -0,0 +1,172 @@
>> +/*
>> + * Copyright (C) 2013 - Virtual Open Systems
>> + * Author: Antonios Motakis <a.motakis@xxxxxxxxxxxxxxxxxxxxxx>
>> + *
>> + * 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.
>> + */
>> +
>> +#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>
>> +#include <linux/io.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/irq.h>
>> +
>> +#include "vfio_platform_private.h"
>> +
>> +#define DRIVER_VERSION "0.5"
>> +#define DRIVER_AUTHOR "Antonios Motakis <a.motakis@xxxxxxxxxxxxxxxxxxxxxx>"
>> +#define DRIVER_DESC "VFIO for platform devices - User Level meta-driver"
>> +
>> +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;
>> +}
>
> I know these are just stubs, but I suspect they should probably return
> error. Thanks,
>

Ok!

> Alex
>
>> +
>> +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 struct platform_driver vfio_platform_driver = {
>> + .probe = vfio_platform_probe,
>> + .remove = vfio_platform_remove,
>> + .driver = {
>> + .name = "vfio-platform",
>> + .owner = THIS_MODULE,
>> + },
>> +};
>> +
>> +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/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
>> new file mode 100644
>> index 0000000..4ae88f8
>> --- /dev/null
>> +++ b/drivers/vfio/platform/vfio_platform_private.h
>> @@ -0,0 +1,22 @@
>> +/*
>> + * Copyright (C) 2013 - Virtual Open Systems
>> + * Author: Antonios Motakis <a.motakis@xxxxxxxxxxxxxxxxxxxxxx>
>> + *
>> + * 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.
>> + */
>> +
>> +#ifndef VFIO_PLATFORM_PRIVATE_H
>> +#define VFIO_PLATFORM_PRIVATE_H
>> +
>> +struct vfio_platform_device {
>> + struct platform_device *pdev;
>> +};
>> +
>> +#endif /* VFIO_PLATFORM_PRIVATE_H */
>> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
>> index 0847b29..b1a8de8 100644
>> --- a/include/uapi/linux/vfio.h
>> +++ b/include/uapi/linux/vfio.h
>> @@ -155,6 +155,7 @@ 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 */
>> };
>
>
>

--
Antonios Motakis
Virtual Open Systems
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Next message: Viresh Kumar: "Re: [PATCH v2] cpufreq: Catch double invocations of cpufreq_freq_transition_begin/end"
Previous message: Ian Abbott: "Re: [PATCH 6/6 v2] staging: comedi: addi_apci_1564: remove use of devpriv->s_EeParameters"
In reply to: Antonios Motakis: "[RFC PATCH v5 05/11] VFIO_PLATFORM: Initial skeleton of VFIO support for platform devices"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]