From: Yi Liu <yi.l.liu@intel.com>
To: alex.williamson@redhat.com, jgg@nvidia.com, kevin.tian@intel.com
Cc: joro@8bytes.org, robin.murphy@arm.com, cohuck@redhat.com,
eric.auger@redhat.com, nicolinc@nvidia.com, kvm@vger.kernel.org,
mjrosato@linux.ibm.com, chao.p.peng@linux.intel.com,
yi.l.liu@intel.com, yi.y.sun@linux.intel.com, peterx@redhat.com,
jasowang@redhat.com, shameerali.kolothum.thodi@huawei.com,
lulu@redhat.com, suravee.suthikulpanit@amd.com,
intel-gvt-dev@lists.freedesktop.org,
intel-gfx@lists.freedesktop.org, linux-s390@vger.kernel.org,
xudong.hao@intel.com, yan.y.zhao@intel.com,
terrence.xu@intel.com, yanting.jiang@intel.com,
zhenzhong.duan@intel.com
Subject: [PATCH v10 17/22] vfio: Move vfio_device_group_unregister() to be the first operation in unregister
Date: Wed, 26 Apr 2023 08:03:16 -0700 [thread overview]
Message-ID: <20230426150321.454465-18-yi.l.liu@intel.com> (raw)
In-Reply-To: <20230426150321.454465-1-yi.l.liu@intel.com>
This can avoid endless vfio_device refcount increasement by userspace,
which would keep blocking the vfio_unregister_group_dev().
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
drivers/vfio/vfio_main.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index c0459872d79a..c3263cb2ea75 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -322,6 +322,12 @@ void vfio_unregister_group_dev(struct vfio_device *device)
bool interrupted = false;
long rc;
+ /*
+ * Prevent new device opened by userspace via the
+ * VFIO_GROUP_GET_DEVICE_FD in the group path.
+ */
+ vfio_device_group_unregister(device);
+
vfio_device_put_registration(device);
rc = try_wait_for_completion(&device->comp);
while (rc <= 0) {
@@ -345,8 +351,6 @@ void vfio_unregister_group_dev(struct vfio_device *device)
}
}
- vfio_device_group_unregister(device);
-
/* Balances device_add in register path */
device_del(&device->device);
--
2.34.1
next prev parent reply other threads:[~2023-04-26 15:04 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-26 15:02 [PATCH v10 00/22] Add vfio_device cdev for iommufd support Yi Liu
2023-04-26 15:03 ` [PATCH v10 01/22] vfio: Allocate per device file structure Yi Liu
2023-04-26 15:03 ` [PATCH v10 02/22] vfio: Refine vfio file kAPIs for KVM Yi Liu
2023-04-26 15:03 ` [PATCH v10 03/22] vfio: Accept vfio device file in the KVM facing kAPI Yi Liu
2023-04-26 15:03 ` [PATCH v10 04/22] kvm/vfio: Rename kvm_vfio_group to prepare for accepting vfio device fd Yi Liu
2023-04-26 15:03 ` [PATCH v10 05/22] kvm/vfio: Accept vfio device file from userspace Yi Liu
2023-05-11 7:11 ` Cédric Le Goater
2023-05-12 7:57 ` Liu, Yi L
2023-04-26 15:03 ` [PATCH v10 06/22] vfio: Pass struct vfio_device_file * to vfio_device_open/close() Yi Liu
2023-04-26 15:03 ` [PATCH v10 07/22] vfio: Block device access via device fd until device is opened Yi Liu
2023-04-26 15:03 ` [PATCH v10 08/22] vfio: Add cdev_device_open_cnt to vfio_group Yi Liu
2023-04-26 15:03 ` [PATCH v10 09/22] vfio: Make vfio_device_open() single open for device cdev path Yi Liu
2023-04-26 15:03 ` [PATCH v10 10/22] vfio-iommufd: Move noiommu compat probe out of vfio_iommufd_bind() Yi Liu
2023-04-26 15:03 ` [PATCH v10 11/22] vfio-iommufd: Split bind/attach into two steps Yi Liu
2023-04-26 15:03 ` [PATCH v10 12/22] vfio: Record devid in vfio_device_file Yi Liu
2023-04-26 15:03 ` [PATCH v10 13/22] vfio-iommufd: Add detach_ioas support for physical VFIO devices Yi Liu
2023-04-26 15:03 ` [PATCH v10 14/22] iommufd/device: Add iommufd_access_detach() API Yi Liu
2023-04-26 15:03 ` [PATCH v10 15/22] vfio-iommufd: Add detach_ioas support for emulated VFIO devices Yi Liu
2023-04-26 15:03 ` [PATCH v10 16/22] vfio: Name noiommu vfio_device with "noiommu-" prefix Yi Liu
2023-04-26 15:03 ` Yi Liu [this message]
2023-04-26 15:03 ` [PATCH v10 18/22] vfio: Add cdev for vfio_device Yi Liu
2023-04-26 15:03 ` [PATCH v10 19/22] vfio: Add VFIO_DEVICE_BIND_IOMMUFD Yi Liu
2023-04-26 15:03 ` [PATCH v10 20/22] vfio: Add VFIO_DEVICE_[AT|DE]TACH_IOMMUFD_PT Yi Liu
2023-04-26 15:03 ` [PATCH v10 21/22] vfio: Compile group optionally Yi Liu
2023-04-26 15:03 ` [PATCH v10 22/22] docs: vfio: Add vfio device cdev description Yi Liu
2023-04-28 9:29 ` [PATCH v10 00/22] Add vfio_device cdev for iommufd support Jiang, Yanting
2023-04-28 15:11 ` Shameerali Kolothum Thodi
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