On Fri, 9 Apr 2021 11:44:19 +0800 Shenming Lu <lushenming@xxxxxxxxxx> wrote: > Some devices only allow selective DMA faulting. Similar to the selective > dirty page tracking, the vendor driver can call vfio_pin_pages() to > indicate the non-faultable scope, we add a new struct vfio_range to > record it, then when the IOPF handler receives any page request out > of the scope, we can directly return with an invalid response. Seems like this highlights a deficiency in the design, that the user can't specify mappings as iopf enabled or disabled. Also, if the vendor driver has pinned pages within the range, shouldn't that prevent them from faulting in the first place? Why do we need yet more tracking structures? Pages pinned by the vendor driver need to count against the user's locked memory limits regardless of iopf. Thanks, Alex
