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(-)
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
*/
--
1.9.1
--
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