Added blocking notifier to IOMMU TYPE1 driver to notify vendor drivers
about DMA_UNMAP.
Exported two APIs vfio_register_notifier() and vfio_unregister_notifier().
Vendor driver should register notifer using these APIs.
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 | 89 ++++++++++++++++++++++++++++++++++++-----
include/linux/vfio.h | 11 +++++
3 files changed, 163 insertions(+), 10 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 28b50ca14c52..ff05ac6b1e90 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1891,6 +1891,79 @@ 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 5add11a147e1..a4bd331ac0fd 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>"
@@ -59,6 +60,7 @@ 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;
};
@@ -549,7 +551,8 @@ static long 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;
}
@@ -768,6 +771,50 @@ static unsigned long vfio_pgsize_bitmap(struct vfio_iommu *iommu)
return bitmap;
}
+/*
+ * This function finds pfn in domain->external_addr_space->pfn_list for given
+ * iova range. If pfn exist, notify pfn to registered notifier list. On
+ * receiving notifier callback, vendor driver should invalidate the mapping and
+ * call vfio_unpin_pages() to unpin this pfn. With that vfio_pfn for this pfn
+ * gets removed from rb tree of pfn_list. That re-arranges rb tree, so while
+ * searching for next vfio_pfn in rb tree, start search from first node again.
+ * If any vendor driver doesn't unpin that pfn, vfio_pfn would not get removed
+ * from rb tree and so in next search vfio_pfn would be same as previous
+ * vfio_pfn. In that case, exit from loop.
+ */
+static void vfio_notifier_call_chain(struct vfio_iommu *iommu,
+ struct vfio_iommu_type1_dma_unmap *unmap)
+{
+ struct vfio_domain *domain = iommu->external_domain;
+ struct rb_node *n;
+ struct vfio_pfn *vpfn = NULL, *prev_vpfn;
+
+ do {
+ prev_vpfn = vpfn;
+ mutex_lock(&domain->external_addr_space->pfn_list_lock);
+
+ n = rb_first(&domain->external_addr_space->pfn_list);
+
+ for (; n; n = rb_next(n), vpfn = NULL) {
+ vpfn = rb_entry(n, struct vfio_pfn, node);
+
+ if ((vpfn->iova >= unmap->iova) &&
+ (vpfn->iova < unmap->iova + unmap->size))
+ break;
+ }
+
+ mutex_unlock(&domain->external_addr_space->pfn_list_lock);
+
+ /* Notify any listeners about DMA_UNMAP */
+ if (vpfn)
+ blocking_notifier_call_chain(&iommu->notifier,
+ VFIO_IOMMU_NOTIFY_DMA_UNMAP,
+ &vpfn->pfn);
+ } while (vpfn && (prev_vpfn != vpfn));
+
+ WARN_ON(vpfn);
+}
+
static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
struct vfio_iommu_type1_dma_unmap *unmap)
{
@@ -844,6 +891,9 @@ unlock:
/* Report how much was unmapped */
unmap->size = unmapped;
+ if (unmapped && iommu->external_domain)
+ vfio_notifier_call_chain(iommu, unmap);
+
return ret;
}
@@ -1418,6 +1468,7 @@ static void *vfio_iommu_type1_open(unsigned long arg)
INIT_LIST_HEAD(&iommu->domain_list);
iommu->dma_list = RB_ROOT;
mutex_init(&iommu->lock);
+ BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier);
return iommu;
}
@@ -1555,16 +1606,34 @@ 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 0609a2052846..4c91ce8bfaeb 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -80,6 +80,10 @@ struct vfio_iommu_driver_ops {
unsigned long *phys_pfn);
long (*unpin_pages)(void *iommu_data, unsigned long *pfn,
long 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);
@@ -137,6 +141,13 @@ extern long vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
extern long vfio_unpin_pages(struct device *dev, unsigned long *pfn,
long 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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