Re: [PATCH v2 4/5] s390x: Move clear reset

[David Hildenbrand <david@redhat.com>]

On 22.11.19 18:15, Janosch Frank wrote:
> On 11/22/19 3:30 PM, David Hildenbrand wrote:
>> On 22.11.19 15:00, Janosch Frank wrote:
>>> Let's also move the clear reset function into the reset handler.
>>>
>>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>>> ---
>>>  target/s390x/cpu-qom.h |  1 +
>>>  target/s390x/cpu.c     | 50 ++++++++----------------------------------
>>>  2 files changed, 10 insertions(+), 41 deletions(-)
>>>
>>> diff --git a/target/s390x/cpu-qom.h b/target/s390x/cpu-qom.h
>>> index 6f0a12042e..dbe5346ec9 100644
>>> --- a/target/s390x/cpu-qom.h
>>> +++ b/target/s390x/cpu-qom.h
>>> @@ -37,6 +37,7 @@ typedef struct S390CPUDef S390CPUDef;
>>>  typedef enum cpu_reset_type {
>>>      S390_CPU_RESET_NORMAL,
>>>      S390_CPU_RESET_INITIAL,
>>> +    S390_CPU_RESET_CLEAR,
>>>  } cpu_reset_type;
>>>  
>>>  /**
>>> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
>>> index 1f423fb676..017181fe4a 100644
>>> --- a/target/s390x/cpu.c
>>> +++ b/target/s390x/cpu.c
>>> @@ -94,6 +94,9 @@ static void s390_cpu_reset(CPUState *s, cpu_reset_type type)
>>>      s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu);
>>>  
>>>      switch (type) {
>>> +    case S390_CPU_RESET_CLEAR:
>>> +        memset(env, 0, offsetof(CPUS390XState, start_initial_reset_fields));
>>
>> I think the preferred term in QEMU is "fall through".
>>
>>> +        /* Fallthrough */
>>>      case S390_CPU_RESET_INITIAL:
>>>          /* initial reset does not clear everything! */
>>>          memset(&env->start_initial_reset_fields, 0,
>>> @@ -121,46 +124,6 @@ static void s390_cpu_reset(CPUState *s, cpu_reset_type type)
>>>      }
>>>  }
>>>  
>>> -/* CPUClass:reset() */
>>> -static void s390_cpu_full_reset(CPUState *s)
>>> -{
>>> -    S390CPU *cpu = S390_CPU(s);
>>> -    S390CPUClass *scc = S390_CPU_GET_CLASS(cpu);
>>> -    CPUS390XState *env = &cpu->env;
>>> -
>>> -    scc->parent_reset(s);
>>> -    cpu->env.sigp_order = 0;
>>> -    s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu);
>>> -
>>> -    memset(env, 0, offsetof(CPUS390XState, end_reset_fields));
>>> -
>>> -    /* architectured initial values for CR 0 and 14 */
>>> -    env->cregs[0] = CR0_RESET;
>>> -    env->cregs[14] = CR14_RESET;
>>> -
>>> -#if defined(CONFIG_USER_ONLY)
>>> -    /* user mode should always be allowed to use the full FPU */
>>> -    env->cregs[0] |= CR0_AFP;
>>> -    if (s390_has_feat(S390_FEAT_VECTOR)) {
>>> -        env->cregs[0] |= CR0_VECTOR;
>>> -    }
>>> -#endif
>>
>> Huh, what happened to that change?
> 
> Btw., wouldn't we need that for both initial and clear reset?

user-only only does a cpu reset when starting up to initialize the cpu.
no other resets will be triggered.
-- 

Thanks,

David / dhildenb