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

Janosch Frank posted 5 patches 6 years, 2 months ago
Maintainers: Halil Pasic <pasic@linux.ibm.com>, Cornelia Huck <cohuck@redhat.com>, Christian Borntraeger <borntraeger@de.ibm.com>, David Hildenbrand <david@redhat.com>, Richard Henderson <rth@twiddle.net>
There is a newer version of this series
[PATCH v2 4/5] s390x: Move clear reset
Posted by Janosch Frank 6 years, 2 months ago 
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));
+        /* 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
-
-    /* architectured initial value for Breaking-Event-Address register */
-    env->gbea = 1;
-
-    env->pfault_token = -1UL;
-
-    /* tininess for underflow is detected before rounding */
-    set_float_detect_tininess(float_tininess_before_rounding,
-                              &env->fpu_status);
-
-    /* Reset state inside the kernel that we cannot access yet from QEMU. */
-    if (kvm_enabled()) {
-        kvm_s390_reset_vcpu(cpu);
-    }
-}
-
 #if !defined(CONFIG_USER_ONLY)
 static void s390_cpu_machine_reset_cb(void *opaque)
 {
@@ -452,6 +415,11 @@ static Property s390x_cpu_properties[] = {
     DEFINE_PROP_END_OF_LIST()
 };
 
+static void s390_cpu_reset_clear(CPUState *s)
+{
+    return s390_cpu_reset(s, S390_CPU_RESET_CLEAR);
+}
+
 static void s390_cpu_class_init(ObjectClass *oc, void *data)
 {
     S390CPUClass *scc = S390_CPU_CLASS(oc);
@@ -468,7 +436,7 @@ static void s390_cpu_class_init(ObjectClass *oc, void *data)
     scc->load_normal = s390_cpu_load_normal;
 #endif
     scc->reset = s390_cpu_reset;
-    cc->reset = s390_cpu_full_reset;
+    cc->reset = s390_cpu_reset_clear;
     cc->class_by_name = s390_cpu_class_by_name,
     cc->has_work = s390_cpu_has_work;
 #ifdef CONFIG_TCG
-- 
2.20.1
Re: [PATCH v2 4/5] s390x: Move clear reset
Posted by David Hildenbrand 6 years, 2 months ago 
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?

Note that we now also do "env->bpbc = false" - is that ok?

-- 

Thanks,

David / dhildenb
Re: [PATCH v2 4/5] s390x: Move clear reset
Posted by Janosch Frank 6 years, 2 months ago 
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?

Seems like I missed it

> 
> Note that we now also do "env->bpbc = false" - is that ok?

That's ok, clear and initial reset do a memset to bpbc, but as reset
normal doesn't we need to set it explicitly.
Re: [PATCH v2 4/5] s390x: Move clear reset
Posted by Janosch Frank 6 years, 2 months ago 
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?

> 
> Note that we now also do "env->bpbc = false" - is that ok?
>
Re: [PATCH v2 4/5] s390x: Move clear reset
Posted by David Hildenbrand 6 years, 2 months ago 
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

Patchew 2.1-devel-b67e4c2

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