s390x/cpu: expose the guest crash information

This patch is the s390 implementation of guest crash information,
similar to commit d187e08dc4 ("i386/cpu: add crash-information QOM
property") and the related commits. We will detect several crash
reasons, with the "disabled wait" being the most important one, since
this is used by all s390 guests as a "panic like" notification.

Demonstrate these ways with examples as follows.

  1. crash-information QOM property;

  Run qemu with -qmp unix:qmp-sock,server, then use utility "qmp-shell"
  to execute "qom-get" command, and might get the result like,

  (QEMU) (QEMU) qom-get path=/machine/unattached/device[0] \
      property=crash-information
  {"return": {"core": 0, "reason": "disabled-wait", "psw-mask": 562956395872256, \
      "type": "s390", "psw-addr": 1102832}}

  2. GUEST_PANICKED event reporting;

  Run qemu with a socket option, and telnet or nc to that,
  -chardev socket,id=qmp,port=4444,host=localhost,server \
  -mon chardev=qmp,mode=control,pretty=on \
  Negotiating the mode by { "execute": "qmp_capabilities" }, and the crash
  information will be reported on a guest crash event like,

  {
    "timestamp": {
        "seconds": 1518004739,
        "microseconds": 552563
    },
    "event": "GUEST_PANICKED",
    "data": {
        "action": "pause",
        "info": {
            "core": 0,
            "psw-addr": 1102832,
            "reason": "disabled-wait",
            "psw-mask": 562956395872256,
            "type": "s390"
        }
    }
  }

  3. log;

  Run qemu with the parameters: -D <logfile> -d guest_errors, to
  specify the logfile and log item. The results might be,

  Guest crashed on cpu 0: disabled-wait
  PSW: 0x0002000180000000 0x000000000010d3f0

Co-authored-by: Jing Liu <liujbjl@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20180209122543.25755-1-borntraeger@de.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[CH: tweaked qapi comment]
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

1 files changed, 7 insertions, 8 deletions

diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index e13c8907df..83e4eaf45d 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -1541,15 +1541,14 @@ static int handle_instruction(S390CPU *cpu, struct kvm_run *run)
     return r;
 }
 
-static void unmanageable_intercept(S390CPU *cpu, const char *str, int pswoffset)
+static void unmanageable_intercept(S390CPU *cpu, S390CrashReason reason,
+                                   int pswoffset)
 {
     CPUState *cs = CPU(cpu);
 
-    error_report("Unmanageable %s! CPU%i new PSW: 0x%016lx:%016lx",
-                 str, cs->cpu_index, ldq_phys(cs->as, cpu->env.psa + pswoffset),
-                 ldq_phys(cs->as, cpu->env.psa + pswoffset + 8));
     s390_cpu_halt(cpu);
-    qemu_system_guest_panicked(NULL);
+    cpu->env.crash_reason = reason;
+    qemu_system_guest_panicked(cpu_get_crash_info(cs));
 }
 
 /* try to detect pgm check loops */
@@ -1579,7 +1578,7 @@ static int handle_oper_loop(S390CPU *cpu, struct kvm_run *run)
         !(oldpsw.mask & PSW_MASK_PSTATE) &&
         (newpsw.mask & PSW_MASK_ASC) == (oldpsw.mask & PSW_MASK_ASC) &&
         (newpsw.mask & PSW_MASK_DAT) == (oldpsw.mask & PSW_MASK_DAT)) {
-        unmanageable_intercept(cpu, "operation exception loop",
+        unmanageable_intercept(cpu, S390_CRASH_REASON_OPINT_LOOP,
                                offsetof(LowCore, program_new_psw));
         return EXCP_HALTED;
     }
@@ -1600,12 +1599,12 @@ static int handle_intercept(S390CPU *cpu)
             r = handle_instruction(cpu, run);
             break;
         case ICPT_PROGRAM:
-            unmanageable_intercept(cpu, "program interrupt",
+            unmanageable_intercept(cpu, S390_CRASH_REASON_PGMINT_LOOP,
                                    offsetof(LowCore, program_new_psw));
             r = EXCP_HALTED;
             break;
         case ICPT_EXT_INT:
-            unmanageable_intercept(cpu, "external interrupt",
+            unmanageable_intercept(cpu, S390_CRASH_REASON_EXTINT_LOOP,
                                    offsetof(LowCore, external_new_psw));
             r = EXCP_HALTED;
             break;