s390x/tcg: rework checking for deliverable interrupts

Currently, enabling/disabling of interrupts is not really supported.

Let's improve interrupt handling code by explicitly checking for
deliverable interrupts only. This is the first step. Checking for
external interrupt subclasses will be done next.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20170928203708.9376-5-david@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

target/s390x/cpu.c

@@ -56,10 +56,12 @@ static void s390_cpu_set_pc(CPUState *cs, vaddr value)
 static bool s390_cpu_has_work(CPUState *cs)
 {
     S390CPU *cpu = S390_CPU(cs);
-    CPUS390XState *env = &cpu->env;
 
-    return (cs->interrupt_request & CPU_INTERRUPT_HARD) &&
-           (env->psw.mask & PSW_MASK_EXT);
+    if (!(cs->interrupt_request & CPU_INTERRUPT_HARD)) {
+        return false;
+    }
+
+    return s390_cpu_has_int(cpu);
 }
 
 #if !defined(CONFIG_USER_ONLY)

target/s390x/excp_helper.c

@@ -435,24 +435,16 @@ void s390_cpu_do_interrupt(CPUState *cs)
 
     s390_cpu_set_state(CPU_STATE_OPERATING, cpu);
     /* handle machine checks */
-    if ((env->psw.mask & PSW_MASK_MCHECK) &&
-        (cs->exception_index == -1)) {
-        if (env->pending_int & INTERRUPT_MCHK) {
-            cs->exception_index = EXCP_MCHK;
-        }
+    if (cs->exception_index == -1 && s390_cpu_has_mcck_int(cpu)) {
+        cs->exception_index = EXCP_MCHK;
     }
     /* handle external interrupts */
-    if ((env->psw.mask & PSW_MASK_EXT) &&
-        cs->exception_index == -1 &&
-        (env->pending_int & INTERRUPT_EXT)) {
+    if (cs->exception_index == -1 && s390_cpu_has_ext_int(cpu)) {
         cs->exception_index = EXCP_EXT;
     }
     /* handle I/O interrupts */
-    if ((env->psw.mask & PSW_MASK_IO) &&
-        (cs->exception_index == -1)) {
-        if (env->pending_int & INTERRUPT_IO) {
-            cs->exception_index = EXCP_IO;
-        }
+    if (cs->exception_index == -1 && s390_cpu_has_io_int(cpu)) {
+        cs->exception_index = EXCP_IO;
     }
 
     switch (cs->exception_index) {
@@ -474,6 +466,7 @@ void s390_cpu_do_interrupt(CPUState *cs)
     }
     cs->exception_index = -1;
 
+    /* we might still have pending interrupts, but not deliverable */
     if (!env->pending_int) {
         cs->interrupt_request &= ~CPU_INTERRUPT_HARD;
     }
@@ -490,7 +483,7 @@ bool s390_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
                the parent EXECUTE insn.  */
             return false;
         }
-        if (env->psw.mask & PSW_MASK_EXT) {
+        if (s390_cpu_has_int(cpu)) {
             s390_cpu_do_interrupt(cs);
             return true;
         }

target/s390x/internal.h

@@ -364,6 +364,10 @@ void cpu_inject_clock_comparator(S390CPU *cpu);
 void cpu_inject_cpu_timer(S390CPU *cpu);
 void cpu_inject_emergency_signal(S390CPU *cpu, uint16_t src_cpu_addr);
 int cpu_inject_external_call(S390CPU *cpu, uint16_t src_cpu_addr);
+bool s390_cpu_has_io_int(S390CPU *cpu);
+bool s390_cpu_has_ext_int(S390CPU *cpu);
+bool s390_cpu_has_mcck_int(S390CPU *cpu);
+bool s390_cpu_has_int(S390CPU *cpu);
 
 
 /* ioinst.c */

target/s390x/interrupt.c

@@ -190,4 +190,50 @@ void s390_crw_mchk(void)
     }
 }
 
+bool s390_cpu_has_mcck_int(S390CPU *cpu)
+{
+    CPUS390XState *env = &cpu->env;
+
+    if (!(env->psw.mask & PSW_MASK_MCHECK)) {
+        return false;
+    }
+
+    return env->pending_int & INTERRUPT_MCHK;
+}
+
+bool s390_cpu_has_ext_int(S390CPU *cpu)
+{
+    CPUS390XState *env = &cpu->env;
+
+    if (!(env->psw.mask & PSW_MASK_EXT)) {
+        return false;
+    }
+
+    return env->pending_int & INTERRUPT_EXT;
+}
+
+bool s390_cpu_has_io_int(S390CPU *cpu)
+{
+    CPUS390XState *env = &cpu->env;
+
+    if (!(env->psw.mask & PSW_MASK_IO)) {
+        return false;
+    }
+
+    return env->pending_int & INTERRUPT_IO;
+}
 #endif
+
+bool s390_cpu_has_int(S390CPU *cpu)
+{
+#ifndef CONFIG_USER_ONLY
+    if (!tcg_enabled()) {
+        return false;
+    }
+    return s390_cpu_has_mcck_int(cpu) ||
+           s390_cpu_has_ext_int(cpu) ||
+           s390_cpu_has_io_int(cpu);
+#else
+    return false;
+#endif
+}