On Thu, 1 Dec 2016 09:21:22 -0700
Alex Williamson <alex.williamson@xxxxxxxxxx> wrote:
> 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
Whoops, somehow that got sent before I added the changes:
--- 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)
@@ -79,8 +39,8 @@
- return -EINVAL;
-
- group = vfio_group_get_from_dev(dev);
-- if (IS_ERR(group))
-- return PTR_ERR(group);
+- if (!group)
+- return -ENODEV;
-
ret = vfio_group_add_container_user(group);
if (ret)
@@ -120,8 +80,8 @@
- return -EINVAL;
-
- group = vfio_group_get_from_dev(dev);
-- if (IS_ERR(group))
-- return PTR_ERR(group);
+- if (!group)
+- return -ENODEV;
-
ret = vfio_group_add_container_user(group);
if (ret)
@@ -149,8 +109,8 @@
+ return -EINVAL;
+
+ group = vfio_group_get_from_dev(dev);
-+ if (IS_ERR(group))
-+ return PTR_ERR(group);
++ if (!group)
++ return -ENODEV;
+
+ switch (type) {
+ case VFIO_IOMMU_NOTIFY:
@@ -175,8 +135,8 @@
+ return -EINVAL;
+
+ group = vfio_group_get_from_dev(dev);
-+ if (IS_ERR(group))
-+ return PTR_ERR(group);
++ if (!group)
++ return -ENODEV;
+
+ switch (type) {
+ case VFIO_IOMMU_NOTIFY:
@@ -252,7 +212,3 @@
/*
* Sub-module helpers
*/
>
> > 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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