> > > be just me, but if you agree please update so that it doesn't give remote > > > idea that it is not valid on VHE enabled hardware. > > > > > > I was trying to run this on the hardware and was trying to understand the > > > details on how to do that. > > > > I see what you're saying, but !CONFIG_ARM64_VHE isn't accurate either. The > > option makes sense if: > > 1) all cores booted in EL2 > > == is_hyp_mode_available() > > 2) ID_AA64MMFR1_EL1.VH=0 or !CONFIG_ARM64_VHE > > == !is_kernel_in_hyp_mode() > > > > The former feels implied for KVM, the latter could be 'Valid if the kernel > > is running in EL1'? WDYT? > > I reckon we can avoid the restriction if we instead add an early stub > like with have for KASLR. That way we could parse the command line > early, and if necessary re-initialize EL2 and drop to EL1 before the > main kernel has to make any decisions about how to initialize things. > That would allow us to have a more general kvm-arm.mode option where a > single kernel Image could support: > > * "protected" mode on nVHE or VHE HW > * "nvhe" mode on nVHE or VHE HW > * "vhe" mode on VHE HW > > ... defaulting to VHE/nVHE modes depending on HW support. > > That would also be somewhat future-proof if we have to add other > variants of protected mode in future, as we could extend the mode option > with parameters for each mode. Agreed that 'mode' is a more future-proof flag and I would very much love to have an option to force nVHE on VHE HW. I however expect that the early stub would not be a trivial addition and would not want to get into that in this series. Could we agree on 'protected' as the only supported value for the time being? David
