On 9 June 2015 at 13:27, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: > On 09/06/15 12:24, Peter Maydell wrote: >> So either: >> * QEMU needs to tell the kernel the MPIDR for each vCPU >> * QEMU needs to ask the kernel the MPIDR for each vCPU >> >> Which is better? The latter is simpler and will work with >> existing kernels. The former would let us (for instance) >> use KVM when we're modelling (real world) boards which have >> particular cluster configurations (which might not match the >> kernel's current simplistic "always 16 CPUs at Aff0" setup). > > Given that it is userspace that provides the description of the > platform, it feels natural to let userspace set MPIDR accordingly. > > This will require some interesting rework in the kernel, but this > doesn't feel too bad. On the other hand QEMU needs to keep working with current kernels, so we need the "ask the kernel" code at least for the moment. Probably needs a capability for "kernel allows userspace to set MPIDR" so we can adapt. -- PMM _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
