On 11/14/2016 11:42 PM, Kirti Wankhede wrote:
> Add a notifier calback to parent's ops structure of mdev device so that per
> device notifer for vfio module is registered through vfio_mdev module.
>
> Signed-off-by: Kirti Wankhede <kwankhede@xxxxxxxxxx>
> Signed-off-by: Neo Jia <cjia@xxxxxxxxxx>
> Change-Id: Iafa6f1721aecdd6e50eb93b153b5621e6d29b637
> ---
> drivers/vfio/mdev/vfio_mdev.c | 19 +++++++++++++++++++
> include/linux/mdev.h | 9 +++++++++
> 2 files changed, 28 insertions(+)
>
> diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
> index ffc36758cb84..1694b1635607 100644
> --- a/drivers/vfio/mdev/vfio_mdev.c
> +++ b/drivers/vfio/mdev/vfio_mdev.c
> @@ -24,6 +24,15 @@
> #define DRIVER_AUTHOR "NVIDIA Corporation"
> #define DRIVER_DESC "VFIO based driver for Mediated device"
>
> +static int vfio_mdev_notifier(struct notifier_block *nb, unsigned long action,
> + void *data)
> +{
> + struct mdev_device *mdev = container_of(nb, struct mdev_device, nb);
> + struct parent_device *parent = mdev->parent;
> +
> + return parent->ops->notifier(mdev, action, data);
> +}
> +
> static int vfio_mdev_open(void *device_data)
> {
> struct mdev_device *mdev = device_data;
> @@ -40,6 +49,11 @@ static int vfio_mdev_open(void *device_data)
> if (ret)
> module_put(THIS_MODULE);
>
> + if (likely(parent->ops->notifier)) {
> + mdev->nb.notifier_call = vfio_mdev_notifier;
> + if (vfio_register_notifier(&mdev->dev, &mdev->nb))
> + pr_err("Failed to register notifier for mdev\n");
> + }
Hi Kirti,
Could you please move the notifier registration before parent->ops->open()?
as you might know, I'm extending your vfio_register_notifier to also include
the attaching/detaching events of vfio_group and kvm. Basically if vfio_group
not attached to any kvm instance, the parent->ops->open() should return -ENODEV
to indicate the failure, but to know whether kvm is available in open(), the
notifier registration should be earlier.
Of course I can call vfio_register_notifier() from an earlier place to
workaround it, but it doesn't seem a canonical way.
--
Thanks,
Jike
> return ret;
> }
>
> @@ -48,6 +62,11 @@ static void vfio_mdev_release(void *device_data)
> struct mdev_device *mdev = device_data;
> struct parent_device *parent = mdev->parent;
>
> + if (likely(parent->ops->notifier)) {
> + if (vfio_unregister_notifier(&mdev->dev, &mdev->nb))
> + pr_err("Failed to unregister notifier for mdev\n");
> + }
> +
> if (likely(parent->ops->release))
> parent->ops->release(mdev);
>
> diff --git a/include/linux/mdev.h b/include/linux/mdev.h
> index 4900cc472364..665afe0a4c31 100644
> --- a/include/linux/mdev.h
> +++ b/include/linux/mdev.h
> @@ -37,6 +37,7 @@ struct mdev_device {
> struct kref ref;
> struct list_head next;
> struct kobject *type_kobj;
> + struct notifier_block nb;
> };
>
> /**
> @@ -85,6 +86,12 @@ struct mdev_device {
> * @mmap: mmap callback
> * @mdev: mediated device structure
> * @vma: vma structure
> + * @notifer: Notifier callback, currently only for
> + * VFIO_IOMMU_NOTIFY_DMA_UNMAP action notified duing
> + * DMA_UNMAP call on mapped iova range.
> + * @mdev: mediated device structure
> + * @action: Action for which notifier is called
> + * @data: Data associated with the notifier
> * Parent device that support mediated device should be registered with mdev
> * module with parent_ops structure.
> **/
> @@ -106,6 +113,8 @@ struct parent_ops {
> ssize_t (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
> unsigned long arg);
> int (*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
> + int (*notifier)(struct mdev_device *mdev, unsigned long action,
> + void *data);
> };
>
> /* interface for exporting mdev supported type attributes */
>
--
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