ppc: Add dummy CIABR SPR

We should implement HW breakpoint/watchpoint, qemu supports them...
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

target-ppc/cpu.h

@@ -1393,6 +1393,7 @@ static inline int cpu_mmu_index (CPUPPCState *env, bool ifetch)
 #define SPR_PSPB              (0x09F)
 #define SPR_DAWR              (0x0B4)
 #define SPR_RPR               (0x0BA)
+#define SPR_CIABR             (0x0BB)
 #define SPR_DAWRX             (0x0BC)
 #define SPR_HFSCR             (0x0BE)
 #define SPR_VRSAVE            (0x100)

target-ppc/translate_init.c

@@ -7589,6 +7589,11 @@ static void gen_spr_book3s_207_dbg(CPUPPCState *env)
                         SPR_NOACCESS, SPR_NOACCESS,
                         &spr_read_generic, &spr_write_generic,
                         KVM_REG_PPC_DAWRX, 0x00000000);
+    spr_register_kvm_hv(env, SPR_CIABR, "CIABR",
+                        SPR_NOACCESS, SPR_NOACCESS,
+                        SPR_NOACCESS, SPR_NOACCESS,
+                        &spr_read_generic, &spr_write_generic,
+                        KVM_REG_PPC_CIABR, 0x00000000);
 }
 
 static void gen_spr_970_dbg(CPUPPCState *env)