26 Sep
2023
26 Sep
'23
8:14 a.m.
From: Liu, Yi L yi.l.liu@intel.com Sent: Thursday, September 21, 2023 3:51 PM
+static void iommufd_user_managed_hwpt_abort(struct iommufd_object *obj) +{
- struct iommufd_hw_pagetable *hwpt =
container_of(obj, struct iommufd_hw_pagetable, obj);- /* The parent->mutex must be held until finalize is called. */
- lockdep_assert_held(&hwpt->parent->mutex);
- iommufd_hw_pagetable_destroy(obj);
+}
Can you elaborate what exactly is protected by parent->mutex?
My gut-feeling that the child just grabs a refcnt on the parent object. It doesn't change any other data of the parent.
+/**
- iommufd_user_managed_hwpt_alloc() - Get a user-managed
hw_pagetable
- @ictx: iommufd context
- @pt_obj: Parent object to an HWPT to associate the domain with
- @idev: Device to get an iommu_domain for
- @flags: Flags from userspace
- @hwpt_type: Requested type of hw_pagetable
- @user_data: user_data pointer
- @dummy: never used
- Allocate a new iommu_domain (must be IOMMU_DOMAIN_NESTED) and
return it as
- a user-managed hw_pagetable.
Add some text to highlight the requirement being a parent, e.g. not an auto domain, must be capable of being a parent, etc.
- case IOMMUFD_OBJ_HW_PAGETABLE:
parent = container_of(pt_obj, struct iommufd_hw_pagetable,obj);
/* No user-managed HWPT on top of an user-managed one*/
if (parent->user_managed) {rc = -EINVAL;goto out_put_pt;}
move to alloc_fn().