Added blocking notifier to IOMMU TYPE1 driver to notify vendor drivers
about DMA_UNMAP.
Exported two APIs vfio_register_notifier() and vfio_unregister_notifier().
Notifier should be registered, if external user wants to use
vfio_pin_pages()/vfio_unpin_pages() APIs to pin/unpin pages.
Vendor driver should use VFIO_IOMMU_NOTIFY_DMA_UNMAP action to invalidate
mappings.
Signed-off-by: Kirti Wankhede <kwankhede@xxxxxxxxxx>
Signed-off-by: Neo Jia <cjia@xxxxxxxxxx>
Change-Id: I5910d0024d6be87f3e8d3e0ca0eaeaaa0b17f271
---
drivers/vfio/vfio.c | 73 +++++++++++++++++++++++++++++++++++++++++
drivers/vfio/vfio_iommu_type1.c | 47 ++++++++++++++++++++------
include/linux/vfio.h | 11 +++++++
3 files changed, 121 insertions(+), 10 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 76d260e98930..4ed1a6a247c6 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1895,6 +1895,79 @@ err_unpin_pages:
}
EXPORT_SYMBOL(vfio_unpin_pages);
+int vfio_register_notifier(struct device *dev, struct notifier_block *nb)
+{
+ struct vfio_container *container;
+ struct vfio_group *group;
+ struct vfio_iommu_driver *driver;
+ ssize_t 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;
+
+ 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);
+ else
+ ret = -EINVAL;
+
+ 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)
+{
+ struct vfio_container *container;
+ struct vfio_group *group;
+ struct vfio_iommu_driver *driver;
+ ssize_t 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;
+
+ container = group->container;
+ down_read(&container->group_lock);
+
+ driver = container->iommu_driver;
+ if (likely(driver && driver->ops->unregister_notifier))
+ ret = driver->ops->unregister_notifier(container->iommu_data,
+ nb);
+ else
+ ret = -EINVAL;
+
+ up_read(&container->group_lock);
+ vfio_group_try_dissolve_container(group);
+
+err_unregister_nb:
+ vfio_group_put(group);
+ return ret;
+}
+EXPORT_SYMBOL(vfio_unregister_notifier);
+
/**
* Module/class support
*/
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index e511073446a0..c2d3a84c447b 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -37,6 +37,7 @@
#include <linux/vfio.h>
#include <linux/workqueue.h>
#include <linux/mdev.h>
+#include <linux/notifier.h>
#define DRIVER_VERSION "0.2"
#define DRIVER_AUTHOR "Alex Williamson <alex.williamson@xxxxxxxxxx>"
@@ -60,6 +61,7 @@ struct vfio_iommu {
struct vfio_domain *external_domain; /* domain for external user */
struct mutex lock;
struct rb_root dma_list;
+ struct blocking_notifier_head notifier;
bool v2;
bool nesting;
};
@@ -550,7 +552,8 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data,
mutex_lock(&iommu->lock);
- if (!iommu->external_domain) {
+ /* Fail if notifier list is empty */
+ if ((!iommu->external_domain) || (!iommu->notifier.head)) {
ret = -EINVAL;
goto pin_done;
}
@@ -867,6 +870,11 @@ unlock:
/* Report how much was unmapped */
unmap->size = unmapped;
+ if (unmapped && iommu->external_domain)
+ blocking_notifier_call_chain(&iommu->notifier,
+ VFIO_IOMMU_NOTIFY_DMA_UNMAP,
+ unmap);
+
return ret;
}
@@ -1474,6 +1482,7 @@ static void *vfio_iommu_type1_open(unsigned long arg)
INIT_LIST_HEAD(&iommu->addr_space_list);
iommu->dma_list = RB_ROOT;
mutex_init(&iommu->lock);
+ BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier);
return iommu;
}
@@ -1610,16 +1619,34 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
return -ENOTTY;
}
+static int vfio_iommu_type1_register_notifier(void *iommu_data,
+ struct notifier_block *nb)
+{
+ struct vfio_iommu *iommu = iommu_data;
+
+ return blocking_notifier_chain_register(&iommu->notifier, nb);
+}
+
+static int vfio_iommu_type1_unregister_notifier(void *iommu_data,
+ struct notifier_block *nb)
+{
+ struct vfio_iommu *iommu = iommu_data;
+
+ return blocking_notifier_chain_unregister(&iommu->notifier, nb);
+}
+
static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
- .name = "vfio-iommu-type1",
- .owner = THIS_MODULE,
- .open = vfio_iommu_type1_open,
- .release = vfio_iommu_type1_release,
- .ioctl = vfio_iommu_type1_ioctl,
- .attach_group = vfio_iommu_type1_attach_group,
- .detach_group = vfio_iommu_type1_detach_group,
- .pin_pages = vfio_iommu_type1_pin_pages,
- .unpin_pages = vfio_iommu_type1_unpin_pages,
+ .name = "vfio-iommu-type1",
+ .owner = THIS_MODULE,
+ .open = vfio_iommu_type1_open,
+ .release = vfio_iommu_type1_release,
+ .ioctl = vfio_iommu_type1_ioctl,
+ .attach_group = vfio_iommu_type1_attach_group,
+ .detach_group = vfio_iommu_type1_detach_group,
+ .pin_pages = vfio_iommu_type1_pin_pages,
+ .unpin_pages = vfio_iommu_type1_unpin_pages,
+ .register_notifier = vfio_iommu_type1_register_notifier,
+ .unregister_notifier = vfio_iommu_type1_unregister_notifier,
};
static int __init vfio_iommu_type1_init(void)
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index ba1b64cb7d4b..dcda8fccefab 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -82,6 +82,10 @@ struct vfio_iommu_driver_ops {
unsigned long *user_pfn,
unsigned long *pfn,
int npage);
+ int (*register_notifier)(void *iommu_data,
+ struct notifier_block *nb);
+ int (*unregister_notifier)(void *iommu_data,
+ struct notifier_block *nb);
};
extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);
@@ -139,6 +143,13 @@ extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
unsigned long *pfn, int npage);
+#define VFIO_IOMMU_NOTIFY_DMA_UNMAP 1
+
+extern int vfio_register_notifier(struct device *dev,
+ struct notifier_block *nb);
+
+extern int vfio_unregister_notifier(struct device *dev,
+ struct notifier_block *nb);
/*
* IRQfd - generic
*/
--
2.7.0
--
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