gdbstub: let the debugger resume from guest panicked state

While in general we forbid a "continue" from the guest panicked
state, it makes sense to have an exception for that when continuing
in the debugger.  Perhaps the guest entered that state due to a bug,
for example, and we want to continue no matter what.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Message-id: 1370272015-9659-3-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

gdbstub.c

@@ -371,6 +371,9 @@ static inline void gdb_continue(GDBState *s)
 #ifdef CONFIG_USER_ONLY
     s->running_state = 1;
 #else
+    if (runstate_check(RUN_STATE_GUEST_PANICKED)) {
+        runstate_set(RUN_STATE_DEBUG);
+    }
     if (!runstate_needs_reset()) {
         vm_start();
     }

vl.c

@@ -610,6 +610,7 @@ static const RunStateTransition runstate_transitions_def[] = {
 
     { RUN_STATE_GUEST_PANICKED, RUN_STATE_PAUSED },
     { RUN_STATE_GUEST_PANICKED, RUN_STATE_FINISH_MIGRATE },
+    { RUN_STATE_GUEST_PANICKED, RUN_STATE_DEBUG },
 
     { RUN_STATE_MAX, RUN_STATE_MAX },
 };