On Thu, Jun 13, 2019 at 12:05:37PM -0700, Andy Lutomirski wrote: > On Thu, Jun 13, 2019 at 9:51 AM Sean Christopherson > <sean.j.christopherson@xxxxxxxxx> wrote: > > If we ditch the workqueue then we probably don't even need to gift the > > page, e.g. I think we allocate the EPC page prior to taking mmap_sem, and > > then simply do gup+kmap around EADD. We'd just need to be careful about > > not allocating EPC pages for ioctls that are guaranteed to fail. > > > > > > Why gup + kmap? Can't you just do STAC; EADD; CLAC? (Using the > appropriate C helpers, of course.) That should work as well, we already have exception fixup on ENCLS. I obviously haven't given much thought to what all we can do once the workqueue goes bye bye :-)
