On Mon, 2021-08-23 at 16:25 +0300, Mike Rapoport wrote: > From: Mike Rapoport <rppt@xxxxxxxxxxxxx> > > Allocate page table using __GFP_PTE_MAPPED so that they will have 4K > PTEs > in the direct map. This allows to switch _PAGE_RW bit each time a > page > table page needs to be made writable or read-only. > > The writability of the page tables is toggled only in the lowest > level page > table modifiction functions and immediately switched off. > > The page tables created early in the boot (including the direct map > page > table) are not write protected. > > Co-developed-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx> > Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx> > Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> > --- I have a second version of the PKS tables series that I think gets all of them. Also, I didn't see any flush anywhere when toggling. I guess the spurious kernel fault handler is doing the work? It might be better to just do a local flush of the address.
