s390x/tcg: cleanup service interrupt injection

There are still some leftovers from old virtio interrupts in there.
Most importantly, we don't have to queue service interrupts anymore.
Just like KVM, we can simply multiplex the SCLP service interrupts and
avoid the queue.

Also, now only valid parameters/cpu_addr will be stored on service
interrupts.
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20170928203708.9376-3-david@redhat.com>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>

target/s390x/cpu.c

@@ -107,7 +107,6 @@ static void s390_cpu_initial_reset(CPUState *s)
     env->gbea = 1;
 
     env->pfault_token = -1UL;
-    env->ext_index = -1;
     for (i = 0; i < ARRAY_SIZE(env->io_index); i++) {
         env->io_index[i] = -1;
     }
@@ -145,7 +144,6 @@ static void s390_cpu_full_reset(CPUState *s)
     env->gbea = 1;
 
     env->pfault_token = -1UL;
-    env->ext_index = -1;
     for (i = 0; i < ARRAY_SIZE(env->io_index); i++) {
         env->io_index[i] = -1;
     }

target/s390x/cpu.h

@@ -53,7 +53,6 @@
 
 #define MMU_USER_IDX 0
 
-#define MAX_EXT_QUEUE 16
 #define MAX_IO_QUEUE 16
 #define MAX_MCHK_QUEUE 16
 
@@ -67,12 +66,6 @@ typedef struct PSW {
     uint64_t addr;
 } PSW;
 
-typedef struct ExtQueue {
-    uint32_t code;
-    uint32_t param;
-    uint32_t param64;
-} ExtQueue;
-
 typedef struct IOIntQueue {
     uint16_t id;
     uint16_t nr;
@@ -128,12 +121,11 @@ struct CPUS390XState {
 
     uint64_t cregs[16]; /* control registers */
 
-    ExtQueue ext_queue[MAX_EXT_QUEUE];
     IOIntQueue io_queue[MAX_IO_QUEUE][8];
     MchkQueue mchk_queue[MAX_MCHK_QUEUE];
 
     int pending_int;
-    int ext_index;
+    uint32_t service_param;
     int io_index[8];
     int mchk_index;
 

target/s390x/excp_helper.c

@@ -241,7 +241,6 @@ static void do_ext_interrupt(CPUS390XState *env)
     S390CPU *cpu = s390_env_get_cpu(env);
     uint64_t mask, addr;
     LowCore *lowcore;
-    ExtQueue *q;
 
     if (!(env->psw.mask & PSW_MASK_EXT)) {
         cpu_abort(CPU(cpu), "Ext int w/o ext mask\n");
@@ -258,20 +257,15 @@ static void do_ext_interrupt(CPUS390XState *env)
         lowcore->cpu_addr = 0;
         env->pending_int &= ~INTERRUPT_EXT_CPU_TIMER;
     } else if (env->pending_int & INTERRUPT_EXT_SERVICE) {
-        g_assert(env->ext_index >= 0);
         /*
          * FIXME: floating IRQs should be considered by all CPUs and
          *        shuld not get cleared by CPU reset.
          */
-        q = &env->ext_queue[env->ext_index];
-        lowcore->ext_int_code = cpu_to_be16(q->code);
-        lowcore->ext_params = cpu_to_be32(q->param);
-        lowcore->ext_params2 = cpu_to_be64(q->param64);
-        lowcore->cpu_addr = cpu_to_be16(env->core_id | VIRTIO_SUBCODE_64);
-        env->ext_index--;
-        if (env->ext_index == -1) {
-            env->pending_int &= ~INTERRUPT_EXT_SERVICE;
-        }
+        lowcore->ext_int_code = cpu_to_be16(EXT_SERVICE);
+        lowcore->ext_params = cpu_to_be32(env->service_param);
+        lowcore->cpu_addr = 0;
+        env->service_param = 0;
+        env->pending_int &= ~INTERRUPT_EXT_SERVICE;
     } else {
         g_assert_not_reached();
     }

target/s390x/internal.h

@@ -360,8 +360,6 @@ void cpu_unmap_lowcore(LowCore *lowcore);
 
 /* interrupt.c */
 void trigger_pgm_exception(CPUS390XState *env, uint32_t code, uint32_t ilen);
-void cpu_inject_ext(S390CPU *cpu, uint32_t code, uint32_t param,
-                    uint64_t param64);
 void cpu_inject_clock_comparator(S390CPU *cpu);
 void cpu_inject_cpu_timer(S390CPU *cpu);
 

target/s390x/interrupt.c

@@ -54,22 +54,12 @@ void program_interrupt(CPUS390XState *env, uint32_t code, int ilen)
 }
 
 #if !defined(CONFIG_USER_ONLY)
-void cpu_inject_ext(S390CPU *cpu, uint32_t code, uint32_t param,
-                    uint64_t param64)
+static void cpu_inject_service(S390CPU *cpu, uint32_t param)
 {
     CPUS390XState *env = &cpu->env;
 
-    if (env->ext_index == MAX_EXT_QUEUE - 1) {
-        /* ugh - can't queue anymore. Let's drop. */
-        return;
-    }
-
-    env->ext_index++;
-    assert(env->ext_index < MAX_EXT_QUEUE);
-
-    env->ext_queue[env->ext_index].code = code;
-    env->ext_queue[env->ext_index].param = param;
-    env->ext_queue[env->ext_index].param64 = param64;
+    /* multiplexing is good enough for sclp - kvm does it internally as well*/
+    env->service_param |= param;
 
     env->pending_int |= INTERRUPT_EXT_SERVICE;
     cpu_interrupt(CPU(cpu), CPU_INTERRUPT_HARD);
@@ -145,7 +135,7 @@ void s390_sclp_extint(uint32_t parm)
     } else {
         S390CPU *dummy_cpu = s390_cpu_addr2state(0);
 
-        cpu_inject_ext(dummy_cpu, EXT_SERVICE, parm, 0);
+        cpu_inject_service(dummy_cpu, parm);
     }
 }