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authorJike Song <jike.song@intel.com>2016-12-16 03:51:06 +0100
committerZhenyu Wang <zhenyuw@linux.intel.com>2016-12-26 02:45:29 +0100
commit364fb6b789ffce44c1b5429086c47b0df6c36aff (patch)
tree92a2937bb6db3d07dd245c7a7f84a3fa1127f8be /drivers/gpu
parentdrm/i915/gvt/kvmgt: check returned slot for gfn (diff)
downloadlinux-364fb6b789ffce44c1b5429086c47b0df6c36aff.tar.xz
linux-364fb6b789ffce44c1b5429086c47b0df6c36aff.zip
drm/i915/gvt/kvmgt: prevent double-release of vgpu
The release action might be triggered from either user's closing mdev or the detaching event of kvm and vfio_group, so this patch introduces an atomic to prevent double-release. Signed-off-by: Jike Song <jike.song@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/i915/gvt/gvt.h1
-rw-r--r--drivers/gpu/drm/i915/gvt/kvmgt.c24
2 files changed, 22 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index ad0e9364ee70..0af17016f33f 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -175,6 +175,7 @@ struct intel_vgpu {
struct notifier_block group_notifier;
struct kvm *kvm;
struct work_struct release_work;
+ atomic_t released;
} vdev;
#endif
};
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 8b3b071a535e..efb01435f13f 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -500,7 +500,16 @@ static int intel_vgpu_open(struct mdev_device *mdev)
goto undo_iommu;
}
- return kvmgt_guest_init(mdev);
+ ret = kvmgt_guest_init(mdev);
+ if (ret)
+ goto undo_group;
+
+ atomic_set(&vgpu->vdev.released, 0);
+ return ret;
+
+undo_group:
+ vfio_unregister_notifier(&mdev->dev, VFIO_GROUP_NOTIFY,
+ &vgpu->vdev.group_notifier);
undo_iommu:
vfio_unregister_notifier(&mdev->dev, VFIO_IOMMU_NOTIFY,
@@ -512,17 +521,26 @@ out:
static void __intel_vgpu_release(struct intel_vgpu *vgpu)
{
struct kvmgt_guest_info *info;
+ int ret;
if (!handle_valid(vgpu->handle))
return;
- vfio_unregister_notifier(&vgpu->vdev.mdev->dev, VFIO_IOMMU_NOTIFY,
+ if (atomic_cmpxchg(&vgpu->vdev.released, 0, 1))
+ return;
+
+ ret = vfio_unregister_notifier(&vgpu->vdev.mdev->dev, VFIO_IOMMU_NOTIFY,
&vgpu->vdev.iommu_notifier);
- vfio_unregister_notifier(&vgpu->vdev.mdev->dev, VFIO_GROUP_NOTIFY,
+ WARN(ret, "vfio_unregister_notifier for iommu failed: %d\n", ret);
+
+ ret = vfio_unregister_notifier(&vgpu->vdev.mdev->dev, VFIO_GROUP_NOTIFY,
&vgpu->vdev.group_notifier);
+ WARN(ret, "vfio_unregister_notifier for group failed: %d\n", ret);
info = (struct kvmgt_guest_info *)vgpu->handle;
kvmgt_guest_exit(info);
+
+ vgpu->vdev.kvm = NULL;
vgpu->handle = 0;
}