s390x/tcg: implement SIGP SENSE RUNNING STATUS

Preparation for TCG, for KVM is this is completely handled in the
kernel.

Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170928203708.9376-20-david@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

target/s390x/cpu.h

@@ -590,6 +590,7 @@ struct sysib_322 {
 #define SIGP_SET_PREFIX        0x0d
 #define SIGP_STORE_STATUS_ADDR 0x0e
 #define SIGP_SET_ARCH          0x12
+#define SIGP_SENSE_RUNNING     0x15
 #define SIGP_STORE_ADTL_STATUS 0x17
 
 /* SIGP condition codes */
@@ -600,6 +601,7 @@ struct sysib_322 {
 
 /* SIGP status bits */
 #define SIGP_STAT_EQUIPMENT_CHECK   0x80000000UL
+#define SIGP_STAT_NOT_RUNNING       0x00000400UL
 #define SIGP_STAT_INCORRECT_STATE   0x00000200UL
 #define SIGP_STAT_INVALID_PARAMETER 0x00000100UL
 #define SIGP_STAT_EXT_CALL_PENDING  0x00000080UL

target/s390x/sigp.c

@@ -234,6 +234,28 @@ static void sigp_set_prefix(CPUState *cs, run_on_cpu_data arg)
     si->cc = SIGP_CC_ORDER_CODE_ACCEPTED;
 }
 
+static void sigp_sense_running(S390CPU *dst_cpu, SigpInfo *si)
+{
+    if (!tcg_enabled()) {
+        /* handled in KVM */
+        set_sigp_status(si, SIGP_STAT_INVALID_ORDER);
+        return;
+    }
+
+    /* sensing without locks is racy, but it's the same for real hw */
+    if (!s390_has_feat(S390_FEAT_SENSE_RUNNING_STATUS)) {
+        set_sigp_status(si, SIGP_STAT_INVALID_ORDER);
+        return;
+    }
+
+    /* If halted (which includes also STOPPED), it is not running */
+    if (CPU(dst_cpu)->halted) {
+        si->cc = SIGP_CC_ORDER_CODE_ACCEPTED;
+    } else {
+        set_sigp_status(si, SIGP_STAT_NOT_RUNNING);
+    }
+}
+
 static int handle_sigp_single_dst(S390CPU *dst_cpu, uint8_t order,
                                   uint64_t param, uint64_t *status_reg)
 {
@@ -282,6 +304,9 @@ static int handle_sigp_single_dst(S390CPU *dst_cpu, uint8_t order,
     case SIGP_CPU_RESET:
         run_on_cpu(CPU(dst_cpu), sigp_cpu_reset, RUN_ON_CPU_HOST_PTR(&si));
         break;
+    case SIGP_SENSE_RUNNING:
+        sigp_sense_running(dst_cpu, &si);
+        break;
     default:
         set_sigp_status(&si, SIGP_STAT_INVALID_ORDER);
     }