target-ppc: Reset SPRs on CPU reset

This resets SPR values to defaults on CPU reset. This should help
with little-endian guests reboot issues.
Signed-off-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: NAndreas Färber <afaerber@suse.de>

target-ppc/cpu.h

@@ -334,6 +334,7 @@ struct ppc_spr_t {
     void (*hea_write)(void *opaque, int spr_num, int gpr_num);
 #endif
     const char *name;
+    target_ulong default_value;
 #ifdef CONFIG_KVM
     /* We (ab)use the fact that all the SPRs will have ids for the
      * ONE_REG interface will have KVM_REG_PPC to use 0 as meaning,

target-ppc/translate_init.c

@@ -631,7 +631,7 @@ static inline void _spr_register(CPUPPCState *env, int num,
 #if defined(CONFIG_KVM)
     spr->one_reg_id = one_reg_id,
 #endif
-    env->spr[num] = initial_value;
+    env->spr[num] = spr->default_value = initial_value;
 }
 
 /* Generic PowerPC SPRs */
@@ -8381,6 +8381,7 @@ static void ppc_cpu_reset(CPUState *s)
     PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
     CPUPPCState *env = &cpu->env;
     target_ulong msr;
+    int i;
 
     pcc->parent_reset(s);
 
@@ -8434,6 +8435,15 @@ static void ppc_cpu_reset(CPUState *s)
     env->dtl_size = 0;
 #endif /* TARGET_PPC64 */
 
+    for (i = 0; i < ARRAY_SIZE(env->spr_cb); i++) {
+        ppc_spr_t *spr = &env->spr_cb[i];
+
+        if (!spr->name) {
+            continue;
+        }
+        env->spr[i] = spr->default_value;
+    }
+
     /* Flush all TLBs */
     tlb_flush(s, 1);
 }