From: Jason Gunthorpe <jgg@nvidia.com>
To: Alexander Gordeev <agordeev@linux.ibm.com>,
David Airlie <airlied@linux.ie>,
Tony Krowiak <akrowiak@linux.ibm.com>,
Alex Williamson <alex.williamson@redhat.com>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Cornelia Huck <cohuck@redhat.com>,
Jonathan Corbet <corbet@lwn.net>, Daniel Vetter <daniel@ffwll.ch>,
dri-devel@lists.freedesktop.org,
Eric Farman <farman@linux.ibm.com>,
Harald Freudenberger <freude@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Heiko Carstens <hca@linux.ibm.com>,
intel-gfx@lists.freedesktop.org,
intel-gvt-dev@lists.freedesktop.org,
Jani Nikula <jani.nikula@linux.intel.com>,
Jason Herne <jjherne@linux.ibm.com>,
Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
kvm@vger.kernel.org, Kirti Wankhede <kwankhede@nvidia.com>,
linux-doc@vger.kernel.org, linux-s390@vger.kernel.org,
Matthew Rosato <mjrosato@linux.ibm.com>,
Peter Oberparleiter <oberpar@linux.ibm.com>,
Halil Pasic <pasic@linux.ibm.com>,
Rodrigo Vivi <rodrigo.vivi@intel.com>,
Sven Schnelle <svens@linux.ibm.com>,
Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
Vineeth Vijayan <vneethv@linux.ibm.com>,
Zhenyu Wang <zhenyuw@linux.intel.com>,
Zhi Wang <zhi.a.wang@intel.com>
Cc: "Tian, Kevin" <kevin.tian@intel.com>,
"Liu, Yi L" <yi.l.liu@intel.com>, Christoph Hellwig <hch@lst.de>
Subject: [PATCH 9/9] vfio: Remove calls to vfio_group_add_container_user()
Date: Tue, 12 Apr 2022 12:53:36 -0300 [thread overview]
Message-ID: <9-v1-a8faf768d202+125dd-vfio_mdev_no_group_jgg@nvidia.com> (raw)
In-Reply-To: <0-v1-a8faf768d202+125dd-vfio_mdev_no_group_jgg@nvidia.com>
When the open_device() op is called the container_users is incremented and
held incremented until close_device(). Thus, so long as drivers call
functions within their open_device()/close_device() region they do not
need to worry about the container_users.
These functions can all only be called between
open_device()/close_device():
vfio_pin_pages()
vfio_unpin_pages()
vfio_dma_rw()
vfio_register_notifier()
vfio_unregister_notifier()
So eliminate the calls to vfio_group_add_container_user() and add a simple
WARN_ON to detect mis-use by drivers.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/vfio/vfio.c | 67 +++++++++------------------------------------
1 file changed, 13 insertions(+), 54 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 3d75505bf3cc26..ab0c3f5635905c 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -2121,9 +2121,8 @@ int vfio_pin_pages(struct vfio_device *vdev, unsigned long *user_pfn, int npage,
if (group->dev_counter > 1)
return -EINVAL;
- ret = vfio_group_add_container_user(group);
- if (ret)
- return ret;
+ if (WARN_ON(!READ_ONCE(vdev->open_count)))
+ return -EINVAL;
container = group->container;
driver = container->iommu_driver;
@@ -2134,8 +2133,6 @@ int vfio_pin_pages(struct vfio_device *vdev, unsigned long *user_pfn, int npage,
else
ret = -ENOTTY;
- vfio_group_try_dissolve_container(group);
-
return ret;
}
EXPORT_SYMBOL(vfio_pin_pages);
@@ -2162,9 +2159,8 @@ int vfio_unpin_pages(struct vfio_device *vdev, unsigned long *user_pfn,
if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
return -E2BIG;
- ret = vfio_group_add_container_user(vdev->group);
- if (ret)
- return ret;
+ if (WARN_ON(!READ_ONCE(vdev->open_count)))
+ return -EINVAL;
container = vdev->group->container;
driver = container->iommu_driver;
@@ -2174,8 +2170,6 @@ int vfio_unpin_pages(struct vfio_device *vdev, unsigned long *user_pfn,
else
ret = -ENOTTY;
- vfio_group_try_dissolve_container(vdev->group);
-
return ret;
}
EXPORT_SYMBOL(vfio_unpin_pages);
@@ -2207,9 +2201,8 @@ int vfio_dma_rw(struct vfio_device *vdev, dma_addr_t user_iova,
if (!data || len <= 0)
return -EINVAL;
- ret = vfio_group_add_container_user(vdev->group);
- if (ret)
- return ret;
+ if (WARN_ON(!READ_ONCE(vdev->open_count)))
+ return -EINVAL;
container = vdev->group->container;
driver = container->iommu_driver;
@@ -2219,9 +2212,6 @@ int vfio_dma_rw(struct vfio_device *vdev, dma_addr_t user_iova,
user_iova, data, len, write);
else
ret = -ENOTTY;
-
- vfio_group_try_dissolve_container(vdev->group);
-
return ret;
}
EXPORT_SYMBOL(vfio_dma_rw);
@@ -2234,10 +2224,6 @@ static int vfio_register_iommu_notifier(struct vfio_group *group,
struct vfio_iommu_driver *driver;
int ret;
- ret = vfio_group_add_container_user(group);
- if (ret)
- return -EINVAL;
-
container = group->container;
driver = container->iommu_driver;
if (likely(driver && driver->ops->register_notifier))
@@ -2245,9 +2231,6 @@ static int vfio_register_iommu_notifier(struct vfio_group *group,
events, nb);
else
ret = -ENOTTY;
-
- vfio_group_try_dissolve_container(group);
-
return ret;
}
@@ -2258,10 +2241,6 @@ static int vfio_unregister_iommu_notifier(struct vfio_group *group,
struct vfio_iommu_driver *driver;
int ret;
- ret = vfio_group_add_container_user(group);
- if (ret)
- return -EINVAL;
-
container = group->container;
driver = container->iommu_driver;
if (likely(driver && driver->ops->unregister_notifier))
@@ -2269,9 +2248,6 @@ static int vfio_unregister_iommu_notifier(struct vfio_group *group,
nb);
else
ret = -ENOTTY;
-
- vfio_group_try_dissolve_container(group);
-
return ret;
}
@@ -2300,10 +2276,6 @@ static int vfio_register_group_notifier(struct vfio_group *group,
if (*events)
return -EINVAL;
- ret = vfio_group_add_container_user(group);
- if (ret)
- return -EINVAL;
-
ret = blocking_notifier_chain_register(&group->notifier, nb);
/*
@@ -2313,25 +2285,6 @@ static int vfio_register_group_notifier(struct vfio_group *group,
if (!ret && set_kvm && group->kvm)
blocking_notifier_call_chain(&group->notifier,
VFIO_GROUP_NOTIFY_SET_KVM, group->kvm);
-
- vfio_group_try_dissolve_container(group);
-
- return ret;
-}
-
-static int vfio_unregister_group_notifier(struct vfio_group *group,
- struct notifier_block *nb)
-{
- int ret;
-
- ret = vfio_group_add_container_user(group);
- if (ret)
- return -EINVAL;
-
- ret = blocking_notifier_chain_unregister(&group->notifier, nb);
-
- vfio_group_try_dissolve_container(group);
-
return ret;
}
@@ -2344,6 +2297,9 @@ int vfio_register_notifier(struct vfio_device *dev, enum vfio_notify_type type,
if (!nb || !events || (*events == 0))
return -EINVAL;
+ if (WARN_ON(!READ_ONCE(dev->open_count)))
+ return -EINVAL;
+
switch (type) {
case VFIO_IOMMU_NOTIFY:
ret = vfio_register_iommu_notifier(group, events, nb);
@@ -2368,12 +2324,15 @@ int vfio_unregister_notifier(struct vfio_device *dev,
if (!nb)
return -EINVAL;
+ if (WARN_ON(!READ_ONCE(dev->open_count)))
+ return -EINVAL;
+
switch (type) {
case VFIO_IOMMU_NOTIFY:
ret = vfio_unregister_iommu_notifier(group, nb);
break;
case VFIO_GROUP_NOTIFY:
- ret = vfio_unregister_group_notifier(group, nb);
+ ret = blocking_notifier_chain_unregister(&group->notifier, nb);
break;
default:
ret = -EINVAL;
--
2.35.1
next prev parent reply other threads:[~2022-04-12 15:54 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-12 15:53 [PATCH 0/9] Make the rest of the VFIO driver interface use vfio_device Jason Gunthorpe
2022-04-12 15:53 ` [PATCH 1/9] vfio: Make vfio_(un)register_notifier accept a vfio_device Jason Gunthorpe
[not found] ` <20220413055524.GB32092@lst.de>
2022-04-13 11:39 ` Jason Gunthorpe
[not found] ` <20220413160601.GA29631@lst.de>
2022-04-13 16:18 ` Jason Gunthorpe
[not found] ` <20220413162946.GB31053@lst.de>
2022-04-13 17:37 ` Jason Gunthorpe
2022-04-13 19:17 ` Wang, Zhi A
2022-04-13 20:04 ` Jason Gunthorpe
2022-04-13 21:08 ` Wang, Zhi A
2022-04-13 23:12 ` Jason Gunthorpe
2022-04-14 2:04 ` Tian, Kevin
2022-04-14 2:15 ` Tian, Kevin
2022-04-14 19:25 ` Eric Farman
2022-04-18 15:28 ` Tony Krowiak
2022-04-18 15:44 ` Jason Gunthorpe
2022-04-18 15:52 ` Tony Krowiak
2022-04-18 15:29 ` Jason J. Herne
2022-04-12 15:53 ` [PATCH 2/9] vfio/ccw: Remove mdev from struct channel_program Jason Gunthorpe
2022-04-14 19:25 ` Eric Farman
2022-04-12 15:53 ` [PATCH 3/9] vfio/mdev: Pass in a struct vfio_device * to vfio_pin/unpin_pages() Jason Gunthorpe
[not found] ` <20220413055717.GC32092@lst.de>
2022-04-13 11:40 ` Jason Gunthorpe
2022-04-14 19:26 ` Eric Farman
2022-04-18 15:25 ` Jason J. Herne
2022-04-19 17:00 ` Jason Gunthorpe
2022-04-18 15:56 ` Tony Krowiak
2022-04-12 15:53 ` [PATCH 4/9] drm/i915/gvt: Change from vfio_group_(un)pin_pages to vfio_(un)pin_pages Jason Gunthorpe
[not found] ` <20220413060110.GF32092@lst.de>
2022-04-13 13:39 ` Jason Gunthorpe
2022-04-12 15:53 ` [PATCH 5/9] vfio: Pass in a struct vfio_device * to vfio_dma_rw() Jason Gunthorpe
[not found] ` <20220413060008.GE32092@lst.de>
2022-04-13 13:39 ` Jason Gunthorpe
2022-04-12 15:53 ` [PATCH 6/9] drm/i915/gvt: Add missing module_put() in error unwind Jason Gunthorpe
2022-04-12 15:53 ` [PATCH 7/9] drm/i915/gvt: Delete kvmgt_vdev::vfio_group Jason Gunthorpe
2022-04-12 15:53 ` [PATCH 8/9] vfio: Remove dead code Jason Gunthorpe
2022-04-12 15:53 ` Jason Gunthorpe [this message]
[not found] ` <20220413061105.GA32701@lst.de>
2022-04-13 14:03 ` [PATCH 9/9] vfio: Remove calls to vfio_group_add_container_user() Jason Gunthorpe
2022-04-14 13:51 ` Matthew Rosato
2022-04-14 14:22 ` Jason Gunthorpe
2022-04-15 2:32 ` Tian, Kevin
2022-04-15 12:07 ` Jason Gunthorpe
2022-04-15 23:45 ` Tian, Kevin
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