arm64: enable mmu

Implement asm_mmu_enable and flush_tlb_all, and then make a final
change to mmu.c in order to link it into arm64. The final change
is to map the code read-only. This is necessary because armv8
forces all writable code shared between EL1 and EL0 to be PXN.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
10 files changed