[Qemu-ppc] [0/48] target-ppc: MMU implementation cleanup for hash MMUs

[David Gibson]

This large patch series makes a serious overhaul of the MMU
implementation for target-ppc.  Previously all the quite dissimilar
PowerPC MMU variants attempted to use a more-or-less common code path,
with dependencies on env->mmu_model scattered throughout.  The
resulting confused code was not worth the handful of saved lines.

This series starts the transition to a new model, where the different
MMU types are represented by appropriate QOM methods on the CPU
object.  For now, only the main translation path - previously
cpu_ppc_handle_mmu_fault() is made such a method, but more could be
added in future.  For now, 32-bit and 64-bit hash page table based
MMUs (the "classic" PPC MMUs) are given their own handle_mmu_fault
functions - the remaining MMU types retain the old code for now, I'm
hoping those more familiar with them will perform a similar conversion
in future though.

There's plenty more cleanup that could be done.  As well as the
obvious work to convert other MMU types, there's room for improvement
in: handling of SDR1 and other SPRs, handling of segment registers,
switching MMU code to user PowerPCCPU instead of CPUPPCState, remove
the duplicate mmu_model in PowerpCCPUClass and CPUPPCState, removing
remaining uses of mmu_model.  But if I tackled all those now, I might
never get this series ready.

Please apply.