> On Oct 16, 2019, at 6:59 PM, Jerry Snitselaar <jsnitsel@xxxxxxxxxx> wrote: > > I guess the mode level 6 check is really for other potential callers > increase_address_space, none exist at the moment, and the condition > of the while loop in alloc_pte should fail if the mode level is 6. Because there is no locking around iommu_map_page(), if there are several concurrent callers of it for the same domain, could it be that it silently corrupt data due to invalid access?