s390x: Enable s390x-softmmu target

This patch adds some code paths for running s390x guest OSs without the
need for KVM.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

cpu-exec.c

@@ -346,6 +346,8 @@ int cpu_exec(CPUState *env1)
                     do_interrupt(env);
 #elif defined(TARGET_M68K)
                     do_interrupt(0);
+#elif defined(TARGET_S390X)
+                    do_interrupt(env);
 #endif
                     env->exception_index = -1;
 #endif
@@ -560,6 +562,12 @@ int cpu_exec(CPUState *env1)
                         do_interrupt(1);
                         next_tb = 0;
                     }
+#elif defined(TARGET_S390X) && !defined(CONFIG_USER_ONLY)
+                    if ((interrupt_request & CPU_INTERRUPT_HARD) &&
+                        (env->psw.mask & PSW_MASK_EXT)) {
+                        do_interrupt(env);
+                        next_tb = 0;
+                    }
 #endif
                    /* Don't use the cached interupt_request value,
                       do_interrupt may have updated the EXITTB flag. */

target-s390x/exec.h

@@ -31,7 +31,16 @@ register struct CPUS390XState *env asm(AREG0);
 
 static inline int cpu_has_work(CPUState *env)
 {
-    return env->interrupt_request & CPU_INTERRUPT_HARD; // guess
+    return ((env->interrupt_request & CPU_INTERRUPT_HARD) &&
+            (env->psw.mask & PSW_MASK_EXT));
+}
+
+static inline void regs_to_env(void)
+{
+}
+
+static inline void env_to_regs(void)
+{
 }
 
 static inline void cpu_pc_from_tb(CPUState *env, TranslationBlock* tb)

target-s390x/helper.c

@@ -82,3 +82,7 @@ int cpu_s390x_handle_mmu_fault (CPUState *env, target_ulong address, int rw,
     return 0;
 }
 #endif /* CONFIG_USER_ONLY */
+
+void do_interrupt (CPUState *env)
+{
+}