On 15/02/16 17:26, Will Deacon wrote: > 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). That's fine, I'll drop that one - we can revisit it and fold it into Suzuki's series. Thanks, M. -- Jazz is not dead. It just smells funny... -- 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
