On Thu, 2014-06-05 at 19:03 +0200, 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 IOCTLs:
>  - VFIO_DEVICE_GET_INFO
>  - VFIO_DEVICE_GET_REGION_INFO
> 
> IRQ info is provided by one of the latter patches.
> 
> Signed-off-by: Antonios Motakis <a.mota...@virtualopensystems.com>
> ---
>  drivers/vfio/platform/vfio_platform.c         | 79 
> +++++++++++++++++++++++++--
>  drivers/vfio/platform/vfio_platform_private.h | 17 ++++++
>  2 files changed, 90 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/vfio/platform/vfio_platform.c 
> b/drivers/vfio/platform/vfio_platform.c
> index 1df76d8..eeaebc4 100644
> --- a/drivers/vfio/platform/vfio_platform.c
> +++ b/drivers/vfio/platform/vfio_platform.c
> @@ -34,17 +34,66 @@
>  #define DRIVER_AUTHOR   "Antonios Motakis <a.mota...@virtualopensystems.com>"
>  #define DRIVER_DESC     "VFIO for platform devices - User Level meta-driver"
>  
> +static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
> +{
> +     int cnt = 0, i;
> +
> +     while (platform_get_resource(vdev->pdev, IORESOURCE_MEM, cnt))
> +             cnt++;
> +
> +     vdev->region = kzalloc(sizeof(struct vfio_platform_region) * cnt,
> +                             GFP_KERNEL);
> +     if (!vdev->region)
> +             return -ENOMEM;
> +
> +     for (i = 0; i < cnt;  i++) {
> +             struct resource *res =
> +                     platform_get_resource(vdev->pdev, IORESOURCE_MEM, i);
> +
> +             if (!res)
> +                     goto err;
> +
> +             vdev->region[i].addr = res->start;
> +             vdev->region[i].size = resource_size(res);
> +             vdev->region[i].flags = 0;
> +     }
> +
> +     vdev->num_regions = cnt;
> +
> +     return 0;
> +err:
> +     kfree(vdev->region);
> +     return -EINVAL;
> +}
> +
> +static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
> +{
> +     vdev->num_regions = 0;
> +     kfree(vdev->region);
> +}
> +
>  static void vfio_platform_release(void *device_data)
>  {
> +     struct vfio_platform_device *vdev = device_data;
> +
> +     vfio_platform_regions_cleanup(vdev);
> +
>       module_put(THIS_MODULE);
>  }
>  
>  static int vfio_platform_open(void *device_data)
>  {
> +     struct vfio_platform_device *vdev = device_data;
> +     int ret;
> +
>       if (!try_module_get(THIS_MODULE))
>               return -ENODEV;
>  
> -     return 0;
> +     ret = vfio_platform_regions_init(vdev);
> +     if (ret)
> +             module_put(THIS_MODULE);
> +
> +     return ret;

The user can call VFIO_GROUP_GET_DEVICE_FD for a single device more than
once, vfio_pci maintains a reference count to make sure we only allocate
and initialize on the first open and cleanup on the last close.

>  }
>  
>  static long vfio_platform_ioctl(void *device_data,
> @@ -65,18 +114,36 @@ static long vfio_platform_ioctl(void *device_data,
>                       return -EINVAL;
>  
>               info.flags = VFIO_DEVICE_FLAGS_PLATFORM;
> -             info.num_regions = 0;
> +             info.num_regions = vdev->num_regions;
>               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_REGION_INFO) {
> +             struct vfio_region_info info;
> +
> +             minsz = offsetofend(struct vfio_region_info, offset);
> +
> +             if (copy_from_user(&info, (void __user *)arg, minsz))
> +                     return -EFAULT;
> +
> +             if (info.argsz < minsz)
> +                     return -EINVAL;
> +
> +             if (info.index >= vdev->num_regions)
> +                     return -EINVAL;
> +
> +             /* map offset to the physical address  */
> +             info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
> +             info.size = vdev->region[info.index].size;
> +             info.flags = vdev->region[info.index].flags;
> +
> +             return copy_to_user((void __user *)arg, &info, minsz);
>  
> -     else if (cmd == VFIO_DEVICE_GET_IRQ_INFO)
> +     } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
>               return -EINVAL;
>  
> -     else if (cmd == VFIO_DEVICE_SET_IRQS)
> +     } else if (cmd == VFIO_DEVICE_SET_IRQS)
>               return -EINVAL;
>  
>       else if (cmd == VFIO_DEVICE_RESET)
> diff --git a/drivers/vfio/platform/vfio_platform_private.h 
> b/drivers/vfio/platform/vfio_platform_private.h
> index 4ae88f8..3448f918 100644
> --- a/drivers/vfio/platform/vfio_platform_private.h
> +++ b/drivers/vfio/platform/vfio_platform_private.h
> @@ -15,8 +15,25 @@
>  #ifndef VFIO_PLATFORM_PRIVATE_H
>  #define VFIO_PLATFORM_PRIVATE_H
>  
> +#define VFIO_PLATFORM_OFFSET_SHIFT   40
> +#define VFIO_PLATFORM_OFFSET_MASK (((u64)(1) << VFIO_PLATFORM_OFFSET_SHIFT) 
> - 1)
> +
> +#define VFIO_PLATFORM_OFFSET_TO_INDEX(off)   \
> +     (off >> VFIO_PLATFORM_OFFSET_SHIFT)
> +
> +#define VFIO_PLATFORM_INDEX_TO_OFFSET(index) \
> +     ((u64)(index) << VFIO_PLATFORM_OFFSET_SHIFT)
> +
> +struct vfio_platform_region {
> +     u64                     addr;
> +     resource_size_t         size;
> +     u32                     flags;
> +};
> +
>  struct vfio_platform_device {
>       struct platform_device          *pdev;
> +     struct vfio_platform_region     *region;

"regions" (plural) has slightly better consistency.  Thanks,

Alex

> +     u32                             num_regions;
>  };
>  
>  #endif /* VFIO_PLATFORM_PRIVATE_H */



--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to