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path: root/drivers/vfio/group.c
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Diffstat (limited to 'drivers/vfio/group.c')
-rw-r--r--drivers/vfio/group.c53
1 files changed, 43 insertions, 10 deletions
diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
index bb24b2f0271e..27d5ba7cf9dc 100644
--- a/drivers/vfio/group.c
+++ b/drivers/vfio/group.c
@@ -133,11 +133,14 @@ static int vfio_group_ioctl_set_container(struct vfio_group *group,
iommufd = iommufd_ctx_from_file(f.file);
if (!IS_ERR(iommufd)) {
- u32 ioas_id;
+ if (IS_ENABLED(CONFIG_VFIO_NOIOMMU) &&
+ group->type == VFIO_NO_IOMMU)
+ ret = iommufd_vfio_compat_set_no_iommu(iommufd);
+ else
+ ret = iommufd_vfio_compat_ioas_create(iommufd);
- ret = iommufd_vfio_compat_ioas_id(iommufd, &ioas_id);
if (ret) {
- iommufd_ctx_put(group->iommufd);
+ iommufd_ctx_put(iommufd);
goto out_unlock;
}
@@ -154,6 +157,18 @@ out_unlock:
return ret;
}
+static void vfio_device_group_get_kvm_safe(struct vfio_device *device)
+{
+ spin_lock(&device->group->kvm_ref_lock);
+ if (!device->group->kvm)
+ goto unlock;
+
+ _vfio_device_get_kvm_safe(device, device->group->kvm);
+
+unlock:
+ spin_unlock(&device->group->kvm_ref_lock);
+}
+
static int vfio_device_group_open(struct vfio_device *device)
{
int ret;
@@ -164,13 +179,23 @@ static int vfio_device_group_open(struct vfio_device *device)
goto out_unlock;
}
+ mutex_lock(&device->dev_set->lock);
+
/*
- * Here we pass the KVM pointer with the group under the lock. If the
- * device driver will use it, it must obtain a reference and release it
- * during close_device.
+ * Before the first device open, get the KVM pointer currently
+ * associated with the group (if there is one) and obtain a reference
+ * now that will be held until the open_count reaches 0 again. Save
+ * the pointer in the device for use by drivers.
*/
- ret = vfio_device_open(device, device->group->iommufd,
- device->group->kvm);
+ if (device->open_count == 0)
+ vfio_device_group_get_kvm_safe(device);
+
+ ret = vfio_device_open(device, device->group->iommufd);
+
+ if (device->open_count == 0)
+ vfio_device_put_kvm(device);
+
+ mutex_unlock(&device->dev_set->lock);
out_unlock:
mutex_unlock(&device->group->group_lock);
@@ -180,7 +205,14 @@ out_unlock:
void vfio_device_group_close(struct vfio_device *device)
{
mutex_lock(&device->group->group_lock);
+ mutex_lock(&device->dev_set->lock);
+
vfio_device_close(device, device->group->iommufd);
+
+ if (device->open_count == 0)
+ vfio_device_put_kvm(device);
+
+ mutex_unlock(&device->dev_set->lock);
mutex_unlock(&device->group->group_lock);
}
@@ -450,6 +482,7 @@ static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group,
refcount_set(&group->drivers, 1);
mutex_init(&group->group_lock);
+ spin_lock_init(&group->kvm_ref_lock);
INIT_LIST_HEAD(&group->device_list);
mutex_init(&group->device_lock);
group->iommu_group = iommu_group;
@@ -803,9 +836,9 @@ void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
if (!vfio_file_is_group(file))
return;
- mutex_lock(&group->group_lock);
+ spin_lock(&group->kvm_ref_lock);
group->kvm = kvm;
- mutex_unlock(&group->group_lock);
+ spin_unlock(&group->kvm_ref_lock);
}
EXPORT_SYMBOL_GPL(vfio_file_set_kvm);