On Thu, 1 Dec 2016 13:20:05 +0800
Jike Song <jike.song@xxxxxxxxx> wrote:
> Currently vfio_register_notifier assumes that there is only one
> notifier chain, which is in vfio_iommu. However, the user might
> also be interested in events other than vfio_iommu, for example,
> vfio_group. Refactor vfio_{un}register_notifier implementation
> to make it feasible.
>
> Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Cc: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
> Reviewed-by: Kirti Wankhede <kwankhede@xxxxxxxxxx>
> Signed-off-by: Jike Song <jike.song@xxxxxxxxx>
> ---
> drivers/vfio/vfio.c | 85 +++++++++++++++++++++++++++++------------
> drivers/vfio/vfio_iommu_type1.c | 8 ++++
> include/linux/vfio.h | 17 +++++++--
> 3 files changed, 82 insertions(+), 28 deletions(-)
I'm making the following fixup to merge this with Christophe's patch
found here https://lkml.org/lkml/2016/11/30/57
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 0aac3ca..cb2ce2d 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -2008,59 +2008,44 @@ int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage)
> }
> EXPORT_SYMBOL(vfio_unpin_pages);
>
> -int vfio_register_notifier(struct device *dev, struct notifier_block *nb)
> +static int vfio_register_iommu_notifier(struct vfio_group *group,
> + unsigned long *events,
> + struct notifier_block *nb)
> {
> struct vfio_container *container;
> - struct vfio_group *group;
> struct vfio_iommu_driver *driver;
> int ret;
>
> - if (!dev || !nb)
> - return -EINVAL;
> -
> - group = vfio_group_get_from_dev(dev);
> - if (IS_ERR(group))
> - return PTR_ERR(group);
> -
> ret = vfio_group_add_container_user(group);
> if (ret)
> - goto err_register_nb;
> + return -EINVAL;
>
> container = group->container;
> down_read(&container->group_lock);
>
> driver = container->iommu_driver;
> if (likely(driver && driver->ops->register_notifier))
> - ret = driver->ops->register_notifier(container->iommu_data, nb);
> + ret = driver->ops->register_notifier(container->iommu_data,
> + events, nb);
> else
> ret = -ENOTTY;
>
> up_read(&container->group_lock);
> vfio_group_try_dissolve_container(group);
>
> -err_register_nb:
> - vfio_group_put(group);
> return ret;
> }
> -EXPORT_SYMBOL(vfio_register_notifier);
>
> -int vfio_unregister_notifier(struct device *dev, struct notifier_block *nb)
> +static int vfio_unregister_iommu_notifier(struct vfio_group *group,
> + struct notifier_block *nb)
> {
> struct vfio_container *container;
> - struct vfio_group *group;
> struct vfio_iommu_driver *driver;
> int ret;
>
> - if (!dev || !nb)
> - return -EINVAL;
> -
> - group = vfio_group_get_from_dev(dev);
> - if (IS_ERR(group))
> - return PTR_ERR(group);
> -
> ret = vfio_group_add_container_user(group);
> if (ret)
> - goto err_unregister_nb;
> + return -EINVAL;
>
> container = group->container;
> down_read(&container->group_lock);
> @@ -2075,7 +2060,57 @@ int vfio_unregister_notifier(struct device *dev, struct notifier_block *nb)
> up_read(&container->group_lock);
> vfio_group_try_dissolve_container(group);
>
> -err_unregister_nb:
> + return ret;
> +}
> +
> +int vfio_register_notifier(struct device *dev, vfio_notify_type_t type,
> + unsigned long *events,
> + struct notifier_block *nb)
> +{
> + struct vfio_group *group;
> + int ret;
> +
> + if (!dev || !nb || !events || (*events == 0))
> + return -EINVAL;
> +
> + group = vfio_group_get_from_dev(dev);
> + if (IS_ERR(group))
> + return PTR_ERR(group);
> +
> + switch (type) {
> + case VFIO_IOMMU_NOTIFY:
> + ret = vfio_register_iommu_notifier(group, events, nb);
> + break;
> + default:
> + ret = -EINVAL;
> + }
> +
> + vfio_group_put(group);
> + return ret;
> +}
> +EXPORT_SYMBOL(vfio_register_notifier);
> +
> +int vfio_unregister_notifier(struct device *dev, vfio_notify_type_t type,
> + struct notifier_block *nb)
> +{
> + struct vfio_group *group;
> + int ret;
> +
> + if (!dev || !nb)
> + return -EINVAL;
> +
> + group = vfio_group_get_from_dev(dev);
> + if (IS_ERR(group))
> + return PTR_ERR(group);
> +
> + switch (type) {
> + case VFIO_IOMMU_NOTIFY:
> + ret = vfio_unregister_iommu_notifier(group, nb);
> + break;
> + default:
> + ret = -EINVAL;
> + }
> +
> vfio_group_put(group);
> return ret;
> }
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 51810a9..b88ad1e 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -1584,10 +1584,18 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
> }
>
> static int vfio_iommu_type1_register_notifier(void *iommu_data,
> + unsigned long *events,
> struct notifier_block *nb)
> {
> struct vfio_iommu *iommu = iommu_data;
>
> + /* clear known events */
> + *events &= ~VFIO_IOMMU_NOTIFY_DMA_UNMAP;
> +
> + /* refuse to register if still events remaining */
> + if (*events)
> + return -EINVAL;
> +
> return blocking_notifier_chain_register(&iommu->notifier, nb);
> }
>
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index 15ff042..fdb8460 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -81,6 +81,7 @@ struct vfio_iommu_driver_ops {
> int (*unpin_pages)(void *iommu_data,
> unsigned long *user_pfn, int npage);
> int (*register_notifier)(void *iommu_data,
> + unsigned long *events,
> struct notifier_block *nb);
> int (*unregister_notifier)(void *iommu_data,
> struct notifier_block *nb);
> @@ -107,14 +108,24 @@ extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
> extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
> int npage);
>
> -#define VFIO_IOMMU_NOTIFY_DMA_UNMAP (1)
> -
> +typedef unsigned short vfio_notify_type_t;
> extern int vfio_register_notifier(struct device *dev,
> + vfio_notify_type_t type,
> + unsigned long *required_events,
> struct notifier_block *nb);
> -
> extern int vfio_unregister_notifier(struct device *dev,
> + vfio_notify_type_t type,
> struct notifier_block *nb);
>
> +/* each type has independent events */
> +enum vfio_notify_type {
> + VFIO_IOMMU_NOTIFY = (__force vfio_notify_type_t)0,
> +};
> +
> +/* events for VFIO_IOMMU_NOTIFY */
> +#define VFIO_IOMMU_NOTIFY_DMA_UNMAP BIT(0)
> +
> +
> /*
> * Sub-module helpers
> */
--
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