ppc: Add dummy SPR_IC for POWER8

It's supposed to be an instruction counter. For now make us not
crash when accessing it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

target-ppc/cpu.h

@@ -1685,6 +1685,7 @@ static inline int cpu_mmu_index (CPUPPCState *env, bool ifetch)
 #define SPR_MPC_MD_DBRAM1     (0x32A)
 #define SPR_RCPU_L2U_RA3      (0x32B)
 #define SPR_TAR               (0x32F)
+#define SPR_IC                (0x350)
 #define SPR_VTB               (0x351)
 #define SPR_MMCRC             (0x353)
 #define SPR_440_INV0          (0x370)

target-ppc/translate_init.c

@@ -7924,6 +7924,17 @@ static void gen_spr_power8_pspb(CPUPPCState *env)
                      KVM_REG_PPC_PSPB, 0);
 }
 
+static void gen_spr_power8_ic(CPUPPCState *env)
+{
+#if !defined(CONFIG_USER_ONLY)
+    spr_register_hv(env, SPR_IC, "IC",
+                    SPR_NOACCESS, SPR_NOACCESS,
+                    &spr_read_generic, SPR_NOACCESS,
+                    &spr_read_generic, &spr_write_generic,
+                    0);
+#endif
+}
+
 static void init_proc_book3s_64(CPUPPCState *env, int version)
 {
     gen_spr_ne_601(env);
@@ -7976,6 +7987,7 @@ static void init_proc_book3s_64(CPUPPCState *env, int version)
         gen_spr_power8_tm(env);
         gen_spr_power8_pspb(env);
         gen_spr_vtb(env);
+        gen_spr_power8_ic(env);
     }
     if (version < BOOK3S_CPU_POWER8) {
         gen_spr_book3s_dbg(env);