On Thu, Feb 11, 2016 at 06:40:04PM +0000, Marc Zyngier wrote: > Having both VHE and non-VHE capable CPUs in the same system > is likely to be a recipe for disaster. > > If the boot CPU has VHE, but a secondary is not, we won't be > able to downgrade and run the kernel at EL1. Add CPU hotplug > to the mix, and this produces a terrifying mess. > > Let's solve the problem once and for all. If you mix VHE and > non-VHE CPUs in the same system, you deserve to loose, and this > patch makes sure you don't get a chance. > > This is implemented by storing the kernel execution level in > a global variable. Secondaries will park themselves in a > WFI loop if they observe a mismatch. Also, the primary CPU > will detect that the secondary CPU has died on a mismatched > execution level. Panic will follow. This should really be based on Suzuki's series for handling generic mismatches: http://lists.infradead.org/pipermail/linux-arm-kernel/2016-January/401727.html To avoid growing a dependency on something that's unlikely to make it for 4.6, I'd be inclined to drop your homegrown checks altogether amd help Suzuki with his series as a separate activity (i.e. it needn't be a blocker imo). Will -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
