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: Kirti Wankhede <kwankhede@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
Signed-off-by: Jike Song <jike.song@xxxxxxxxx>
---
drivers/vfio/vfio.c | 87 +++++++++++++++++++++++++++++++++++++++-------------
include/linux/vfio.h | 16 ++++++++--
2 files changed, 78 insertions(+), 25 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index c815067..ec62bec 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -2007,23 +2007,24 @@ 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;
+ /* clear known events */
+ *events &= ~VFIO_IOMMU_NOTIFY_DMA_UNMAP;
- group = vfio_group_get_from_dev(dev);
- if (IS_ERR(group))
- return PTR_ERR(group);
+ /* refuse to register if still events remaining */
+ if (*events)
+ return -EINVAL;
ret = vfio_group_add_container_user(group);
if (ret)
- goto err_register_nb;
+ return -EINVAL;
container = group->container;
down_read(&container->group_lock);
@@ -2037,29 +2038,19 @@ int vfio_register_notifier(struct device *dev, struct notifier_block *nb)
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);
@@ -2074,7 +2065,59 @@ 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)
+ return -EINVAL;
+ if (!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/include/linux/vfio.h b/include/linux/vfio.h
index 15ff042..6f3ff31 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -107,14 +107,24 @@ 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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