On Sat Nov 5, 2022 at 6:00 PM AEST, Christophe Leroy wrote: > > > Le 04/11/2022 à 18:27, Andrew Donnellan a écrit : > > powerpc unfortunately has too many places where we run stuff in real mode. > > > > With CONFIG_VMAP_STACK enabled, this means we need to be able to swap the > > stack pointer to use the linear mapping when we enter a real mode section, > > and back afterwards. > > > > Store the top bits of the stack pointer in both the linear map and the > > vmalloc space in the PACA, and add some helper macros/functions to swap > > between them. > > That may work when pagesize is 64k because stack is on a single page, > but I doubt is works with 4k pages, because vmalloc may allocate non > contiguous pages.
Yeah. This could be a first-stage though, and depend on 64k page size and stack size, or !KVM or whatever. When the real-mode code is solved, that could be relaxed. Thanks, Nick
