Re: [PULL 00/30] ppc-for-5.2 queue 20200904

[Cornelia Huck <cohuck@redhat.com>]

On Mon, 7 Sep 2020 16:31:24 +0200
Laurent Vivier <lvivier@redhat.com> wrote:

> On 07/09/2020 16:05, Philippe Mathieu-Daudé wrote:
> > Hi Thiago,
> > 
> > On 9/7/20 3:29 PM, Laurent Vivier wrote:  
> >> On 07/09/2020 04:38, David Gibson wrote:  
> >>> On Sun, Sep 06, 2020 at 04:20:10PM +0100, Peter Maydell wrote:  

> >>>> The 'check-tcg' tests for the linux-user static build also
> >>>> failed on an s390x test:
> >>>>
> >>>>   CHECK   debian-s390x-cross
> >>>>   BUILD   s390x-linux-user guest-tests with docker qemu/debian-s390x-cross
> >>>>   RUN     tests for s390x
> >>>>   TEST    threadcount on s390x
> >>>> Unhandled trap: 0x10003  
> >>
> >> This is EXCP_HALTED (include/exec/cpu-all.h)
> >>
> >> The message error comes from cpu_loop() in linux-user/s390x/cpu_loop.c.
> >>
> >> The trap can only come from accel/tcg/cpu-exec.c
> >>
> >>     679 int cpu_exec(CPUState *cpu)
> >>     680 {
> >> ...
> >>     688     if (cpu_handle_halt(cpu)) {
> >>     689         return EXCP_HALTED;
> >>     690     }
> >>
> >> and
> >>
> >>     428 static inline bool cpu_handle_halt(CPUState *cpu)
> >>     429 {
> >>     430     if (cpu->halted) {
> >> ...
> >>     441         if (!cpu_has_work(cpu)) {
> >>     442             return true;
> >>     443         }
> >>
> >> and
> >>
> >>      58 static bool s390_cpu_has_work(CPUState *cs)
> >>      59 {
> >>      60     S390CPU *cpu = S390_CPU(cs);
> >>      61
> >>      62     /* STOPPED cpus can never wake up */
> >>      63     if (s390_cpu_get_state(cpu) != S390_CPU_STATE_LOAD &&
> >>      64         s390_cpu_get_state(cpu) != S390_CPU_STATE_OPERATING) {
> >>      65         return false;
> >>      66     }
> >>      67
> >>      68     if (!(cs->interrupt_request & CPU_INTERRUPT_HARD)) {
> >>      69         return false;
> >>      70     }
> >>      71
> >>      72     return s390_cpu_has_int(cpu);
> >>      73 }
> >>
> >> and in target/s390x/cpu.h:
> >>
> >>     772 #ifndef CONFIG_USER_ONLY
> >>     773 unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu);
> >>     774 #else
> >>     775 static inline unsigned int s390_cpu_set_state(uint8_t cpu_state,
> >> S390CPU *cpu)
> >>     776 {
> >>     777     return 0;
> >>     778 }
> >>     779 #endif /* CONFIG_USER_ONLY */
> >>     780 static inline uint8_t s390_cpu_get_state(S390CPU *cpu)
> >>     781 {
> >>     782     return cpu->env.cpu_state;
> >>     783 }
> >>
> >> As cpu_state is never set, perhaps in case of linux-user it should
> >> always return S390_CPU_STATE_OPERATING?

Possibly, we should not have any state handling for linux-user.

> >>
> >> Something like:
> >>
> >> diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
> >> index 035427521cec..8a8628fcdcc6 100644
> >> --- a/target/s390x/cpu.h
> >> +++ b/target/s390x/cpu.h
> >> @@ -771,16 +771,20 @@ int s390_assign_subch_ioeventfd(EventNotifier
> >> *notifier, uint32_t sch_id,
> >>                                  int vq, bool assign);
> >>  #ifndef CONFIG_USER_ONLY
> >>  unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu);
> >> +static inline uint8_t s390_cpu_get_state(S390CPU *cpu)
> >> +{
> >> +    return cpu->env.cpu_state;
> >> +}
> >>  #else
> >>  static inline unsigned int s390_cpu_set_state(uint8_t cpu_state,
> >> S390CPU *cpu)
> >>  {
> >>      return 0;
> >>  }
> >> -#endif /* CONFIG_USER_ONLY */
> >>  static inline uint8_t s390_cpu_get_state(S390CPU *cpu)
> >>  {
> >> -    return cpu->env.cpu_state;
> >> +    return S390_CPU_STATE_OPERATING;
> >>  }
> >> +#endif /* CONFIG_USER_ONLY */  
> > 
> > Since this is the effect of your "target/s390x: Use start-powered-off
> > CPUState property" patch, can you have a look please?
> >   
> 
> For information, the problem appears only with "--enable-debug-tcg" (I
> have also "--static --enable-linux-user --disable-system --disable-tools").

Ah, so that's why this did not show up in my testing.

> 
> CC: David Hildenbrand (s390 TCG CPU maintainer)
> 
> Thanks,
> Laurent