s390x/kvm: Log unmanageable program interruptions

The kernel only drops to userspace if an endless program interrupt loop
has been detected. Let's print an error message in this case to inform
the user about the crash and stop the affected CPU with a panic event,
just like it is already done for the external interruption loop detection.
Signed-off-by: NThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: NJens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>

target-s390x/kvm.c

@@ -83,6 +83,7 @@
 #define DIAG_KVM_BREAKPOINT             0x501
 
 #define ICPT_INSTRUCTION                0x04
+#define ICPT_PROGRAM                    0x08
 #define ICPT_EXT_INT                    0x14
 #define ICPT_WAITPSW                    0x1c
 #define ICPT_SOFT_INTERCEPT             0x24
@@ -966,6 +967,11 @@ static int handle_intercept(S390CPU *cpu)
         case ICPT_INSTRUCTION:
             r = handle_instruction(cpu, run);
             break;
+        case ICPT_PROGRAM:
+            unmanageable_intercept(cpu, "program interrupt",
+                                   offsetof(LowCore, program_new_psw));
+            r = EXCP_HALTED;
+            break;
         case ICPT_EXT_INT:
             unmanageable_intercept(cpu, "external interrupt",
                                    offsetof(LowCore, external_new_psw));