Hi Jason, On 4/29/21 10:04 PM, Jason Gunthorpe wrote: > On Thu, Apr 29, 2021 at 03:26:55PM +0200, Auger Eric wrote: >> From the pseudo code, >> >> gpa_ioasid_id = ioctl(ioasid_fd, CREATE_IOASID, ..) >> ioctl(ioasid_fd, SET_IOASID_PAGE_TABLES, ..) >> >> I fail to understand whether the SET_IOASID_PAGE_TABLES would apply to >> the whole IOASIDs within /dev/ioasid or to a specific one. > > Sorry, nearly every IOCTL would be scoped to a specific IOASID as one > of the arguments. OK thank you for the clarification. > >> Also in subsequent emails when you talk about IOASID, is it the >> ioasid_id, just to double check the terminology. > > I am refering to IOASID as 'handle of the page table object inside the > /dev/ioasid fd'. If that is equal to some HW value or not I think > remains as decision point. OK > > Basically the fd has an xarray of 'struct [something] *' and the > IOASID is index to that FD's private xarray. This is necessary to > create proper security as even if we have global PASID numbers or > something they still need to be isolated to only the FD that has > been authorized access. > >>> nested_ioasid = ioctl(ioasid_fd, CREATE_NESTED_IOASID, gpa_ioasid_id); >>> ioctl(ioasid_fd, SET_NESTED_IOASID_PAGE_TABLES, nested_ioasid, ..) >> is the nested_ioasid the allocated PASID id or is it a complete >> different object id. > > It is the IOASID handle above. ok as per the following emails and below comment IOASID and PASID are different.The first would be a logic ID wgile the second the HW ID. Thanks Eric > >>> >>> // IOMMU will match on the device RID, no PASID: >>> ioctl(vfio_device, ATTACH_IOASID, nested_ioasid); >>> >>> // IOMMU will match on the device RID and PASID: >>> ioctl(vfio_device, ATTACH_IOASID_PASID, pasid, nested_ioasid); >> here I see you pass a different pasid, so I guess they are different, in >> which case you would need to have an allocator function for this pasid, >> right? > > Yes, the underlying HW ID (PASID or substream id or whatver) is > something slightly different > > Jason >
