cpu: Turn cpu_unassigned_access() into a CPUState hook

Use it for all targets, but be careful not to pass invalid CPUState.
cpu_single_env can be NULL, e.g. on Xen.

Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/target-alpha/cpu.c b/target-alpha/cpu.c
index 4e62eaf..2670805 100644
--- a/target-alpha/cpu.c
+++ b/target-alpha/cpu.c
@@ -263,6 +263,7 @@
     cc->class_by_name = alpha_cpu_class_by_name;
     cc->do_interrupt = alpha_cpu_do_interrupt;
     cc->dump_state = alpha_cpu_dump_state;
+    cpu_class_set_do_unassigned_access(cc, alpha_cpu_unassigned_access);
     device_class_set_vmsd(dc, &vmstate_alpha_cpu);
 }
 
diff --git a/target-alpha/cpu.h b/target-alpha/cpu.h
index 2156a1e..01f4ebb 100644
--- a/target-alpha/cpu.h
+++ b/target-alpha/cpu.h
@@ -457,9 +457,9 @@
 void cpu_alpha_store_fpcr (CPUAlphaState *env, uint64_t val);
 #ifndef CONFIG_USER_ONLY
 void swap_shadow_regs(CPUAlphaState *env);
-QEMU_NORETURN void cpu_unassigned_access(CPUAlphaState *env1,
-                                         hwaddr addr, int is_write,
-                                         int is_exec, int unused, int size);
+QEMU_NORETURN void alpha_cpu_unassigned_access(CPUState *cpu, hwaddr addr,
+                                               bool is_write, bool is_exec,
+                                               int unused, unsigned size);
 #endif
 
 /* Bits in TB->FLAGS that control how translation is processed.  */
diff --git a/target-alpha/mem_helper.c b/target-alpha/mem_helper.c
index 3d2cd61..7160a1c 100644
--- a/target-alpha/mem_helper.c
+++ b/target-alpha/mem_helper.c
@@ -109,11 +109,15 @@
     cpu_loop_exit(env);
 }
 
-void cpu_unassigned_access(CPUAlphaState *env, hwaddr addr,
-                           int is_write, int is_exec, int unused, int size)
+void alpha_cpu_unassigned_access(CPUState *cs, hwaddr addr,
+                                 bool is_write, bool is_exec, int unused,
+                                 unsigned size)
 {
+    AlphaCPU *cpu = ALPHA_CPU(cs);
+    CPUAlphaState *env = &cpu->env;
+
     env->trap_arg0 = addr;
-    env->trap_arg1 = is_write;
+    env->trap_arg1 = is_write ? 1 : 0;
     dynamic_excp(env, 0, EXCP_MCHK, 0);
 }