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Message-ID: <1479358706-19936-1-git-send-email-kwankhede@nvidia.com>
Date: Thu, 17 Nov 2016 10:28:26 +0530
From: Kirti Wankhede <kwankhede@...dia.com>
To: <alex.williamson@...hat.com>, <pbonzini@...hat.com>,
<kraxel@...hat.com>, <cjia@...dia.com>
CC: <qemu-devel@...gnu.org>, <kvm@...r.kernel.org>,
<kevin.tian@...el.com>, <jike.song@...el.com>,
<bjsdjshi@...ux.vnet.ibm.com>, <linux-kernel@...r.kernel.org>,
Kirti Wankhede <kwankhede@...dia.com>
Subject: Re: [PATCH v14 11/22] vfio iommu: Add blocking notifier to notify DMA_UNMAP
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@...dia.com>
Signed-off-by: Neo Jia <cjia@...dia.com>
Change-Id: I5910d0024d6be87f3e8d3e0ca0eaeaaa0b17f271
---
drivers/vfio/vfio.c | 73 ++++++++++++++++++++++++++++++++++++++++
drivers/vfio/vfio_iommu_type1.c | 74 +++++++++++++++++++++++++++++++++--------
include/linux/vfio.h | 12 +++++++
3 files changed, 146 insertions(+), 13 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index bd36c16b0ef2..301eed07a0ab 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1901,6 +1901,79 @@ 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;
+ 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;
+
+ 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 = -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)
+{
+ 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;
+
+ 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 = -ENOTTY;
+
+ 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 db0901f8a149..511c517bae15 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -38,6 +38,7 @@
#include <linux/workqueue.h>
#include <linux/pid_namespace.h>
#include <linux/mdev.h>
+#include <linux/notifier.h>
#define DRIVER_VERSION "0.2"
#define DRIVER_AUTHOR "Alex Williamson <alex.williamson@...hat.com>"
@@ -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;
};
@@ -561,7 +563,8 @@ 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;
}
@@ -776,9 +779,9 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
struct vfio_iommu_type1_dma_unmap *unmap)
{
uint64_t mask;
- struct vfio_dma *dma;
+ struct vfio_dma *dma, *dma_last = NULL;
size_t unmapped = 0;
- int ret = 0;
+ int ret = 0, retries;
mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1;
@@ -788,7 +791,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
return -EINVAL;
WARN_ON(mask & PAGE_MASK);
-
+again:
mutex_lock(&iommu->lock);
/*
@@ -844,6 +847,32 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
*/
if (dma->task->mm != current->mm)
break;
+
+ if (!RB_EMPTY_ROOT(&dma->pfn_list)) {
+ struct vfio_iommu_type1_dma_unmap nb_unmap;
+
+ if (dma_last == dma) {
+ BUG_ON(++retries > 10);
+ } else {
+ dma_last = dma;
+ retries = 0;
+ }
+
+ nb_unmap.iova = dma->iova;
+ nb_unmap.size = dma->size;
+
+ /*
+ * Notify anyone (mdev vendor drivers) to invalidate and
+ * unmap iovas within the range we're about to unmap.
+ * Vendor drivers MUST unpin pages in response to an
+ * invalidation.
+ */
+ mutex_unlock(&iommu->lock);
+ blocking_notifier_call_chain(&iommu->notifier,
+ VFIO_IOMMU_NOTIFY_DMA_UNMAP,
+ &nb_unmap);
+ goto again;
+ }
unmapped += dma->size;
vfio_remove_dma(iommu, dma);
}
@@ -1419,6 +1448,7 @@ 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;
}
@@ -1553,16 +1583,34 @@ 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 3c862a030029..6ab13f7e2920 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -80,6 +80,10 @@ struct vfio_iommu_driver_ops {
unsigned long *phys_pfn);
int (*unpin_pages)(void *iommu_data,
unsigned long *user_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);
@@ -103,6 +107,14 @@ 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)
+
+extern int vfio_register_notifier(struct device *dev,
+ struct notifier_block *nb);
+
+extern int vfio_unregister_notifier(struct device *dev,
+ struct notifier_block *nb);
+
/*
* Sub-module helpers
*/
--
2.7.0
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