On Tue, Jan 31, 2023 at 09:26:56PM +0000, Marc Zyngier wrote: > On Tue, 31 Jan 2023 20:04:15 +0000, Oliver Upton <oliver.upton@xxxxxxxxx> wrote: > > Marc, I'm curious, how do you plan to glue hVHE + NV together (if at > > all)? We may need two separate options for this so the user could > > separately configure NV for their hVHE KVM instance. > > I really don't plan to support them together. But if we wanted to > support something, I'd rather express it as a composition of the > various options, as I suggested to Suzuki earlier. Something along the > lines of: > > kvm-arm.mode=hvhe,nested > > But the extra complexity is mind-boggling, frankly. And the result > will suck terribly. NV is already exit-heavy, compared to single-level > virtualisation. But now you double the cost of the exit by moving all > the load/put work into the entry-exit phase. Oh yeah, that wasn't a feature request, just wanted to pick your brain for a moment :) Hopefully nobody comes along asking for it in the future, heh. -- Thanks, Oliver
