On Sat, 28 Dec 2019 11:57:14 +0000 Russell King <rmk+kernel@xxxxxxxxxxxxxxx> wrote: > Booting 5.4 on LX2160A reveals that KVM is non-functional: > > kvm: Limiting the IPA size due to kernel Virtual Address limit > kvm [1]: IPA Size Limit: 43bits > kvm [1]: IDMAP intersecting with HYP VA, unable to continue > kvm [1]: error initializing Hyp mode: -22 > > Debugging shows: > > kvm [1]: IDMAP page: 81a26000 > kvm [1]: HYP VA range: 0:22ffffffff > > as RAM is located at: > > 80000000-fbdfffff : System RAM > 2080000000-237fffffff : System RAM > > Comparing this with the same kernel on Armada 8040 shows: > > kvm: Limiting the IPA size due to kernel Virtual Address limit > kvm [1]: IPA Size Limit: 43bits > kvm [1]: IDMAP page: 2a26000 > kvm [1]: HYP VA range: 4800000000:493fffffff > ... > kvm [1]: Hyp mode initialized successfully > > which indicates that hyp_va_msb is set, and is always set to the > opposite value of the idmap page to avoid the overlap. This does not > happen with the LX2160A. > > Further debugging shows vabits_actual = 39, kva_msb = 38 on LX2160A and > kva_msb = 33 on Armada 8040. Looking at the bit layout of the HYP VA, > there is still one bit available for hyp_va_msb. Set this bit > appropriately. This allows kvm to be functional on the LX2160A, but > without any HYP VA randomisation: > > kvm: Limiting the IPA size due to kernel Virtual Address limit > kvm [1]: IPA Size Limit: 43bits > kvm [1]: IDMAP page: 81a24000 > kvm [1]: HYP VA range: 4000000000:62ffffffff > ... > kvm [1]: Hyp mode initialized successfully > > Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> I've applied this to kvmarm-next with a couple of cleanups, and preserving the fallback when the tag is zero (only the mask gets applied, without any ROR or ADD). M. -- Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
