Re: [PATCH v11 18/25] cpu: Move synchronize_from_tb() to tcg_ops

[Claudio Fontana]

On 12/11/20 6:47 PM, Claudio Fontana wrote:
> On 12/11/20 6:28 PM, Richard Henderson wrote:
>> On 12/11/20 11:10 AM, Claudio Fontana wrote:
>>> On 12/11/20 6:05 PM, Richard Henderson wrote:
>>>> On 12/11/20 2:31 AM, Claudio Fontana wrote:
>>>>> From: Eduardo Habkost <ehabkost@redhat.com>
>>>>>
>>>>> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
>>>>> [claudio: wrapped in CONFIG_TCG]
>>>>> Signed-off-by: Claudio Fontana <cfontana@suse.de>
>>>>> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>>>>> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
>>>>> ---
>>>>>  include/hw/core/cpu.h         |  8 --------
>>>>>  include/hw/core/tcg-cpu-ops.h | 12 ++++++++++++
>>>>>  accel/tcg/cpu-exec.c          |  4 ++--
>>>>>  target/arm/cpu.c              |  4 +++-
>>>>>  target/avr/cpu.c              |  2 +-
>>>>>  target/hppa/cpu.c             |  2 +-
>>>>>  target/i386/tcg/tcg-cpu.c     |  2 +-
>>>>>  target/microblaze/cpu.c       |  2 +-
>>>>>  target/mips/cpu.c             |  4 +++-
>>>>>  target/riscv/cpu.c            |  2 +-
>>>>>  target/rx/cpu.c               |  2 +-
>>>>>  target/sh4/cpu.c              |  2 +-
>>>>>  target/sparc/cpu.c            |  2 +-
>>>>>  target/tricore/cpu.c          |  2 +-
>>>>>  14 files changed, 29 insertions(+), 21 deletions(-)
>>>>>
>>>>> diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
>>>>> index ea648d52ad..83007d262c 100644
>>>>> --- a/include/hw/core/cpu.h
>>>>> +++ b/include/hw/core/cpu.h
>>>>> @@ -110,13 +110,6 @@ struct TranslationBlock;
>>>>>   *       If the target behaviour here is anything other than "set
>>>>>   *       the PC register to the value passed in" then the target must
>>>>>   *       also implement the synchronize_from_tb hook.
>>>>> - * @synchronize_from_tb: Callback for synchronizing state from a TCG
>>>>> - *       #TranslationBlock. This is called when we abandon execution
>>>>> - *       of a TB before starting it, and must set all parts of the CPU
>>>>> - *       state which the previous TB in the chain may not have updated.
>>>>> - *       This always includes at least the program counter; some targets
>>>>> - *       will need to do more. If this hook is not implemented then the
>>>>> - *       default is to call @set_pc(tb->pc).
>>>>>   * @tlb_fill: Callback for handling a softmmu tlb miss or user-only
>>>>>   *       address fault.  For system mode, if the access is valid, call
>>>>>   *       tlb_set_page and return true; if the access is invalid, and
>>>>> @@ -193,7 +186,6 @@ struct CPUClass {
>>>>>      void (*get_memory_mapping)(CPUState *cpu, MemoryMappingList *list,
>>>>>                                 Error **errp);
>>>>>      void (*set_pc)(CPUState *cpu, vaddr value);
>>>>> -    void (*synchronize_from_tb)(CPUState *cpu, struct TranslationBlock 
>>>>> *tb);
>>>>>      bool (*tlb_fill)(CPUState *cpu, vaddr address, int size,
>>>>>                       MMUAccessType access_type, int mmu_idx,
>>>>>                       bool probe, uintptr_t retaddr);
>>>>> diff --git a/include/hw/core/tcg-cpu-ops.h b/include/hw/core/tcg-cpu-ops.h
>>>>> index 4475ef0996..e1d50b3c8b 100644
>>>>> --- a/include/hw/core/tcg-cpu-ops.h
>>>>> +++ b/include/hw/core/tcg-cpu-ops.h
>>>>> @@ -10,6 +10,8 @@
>>>>>  #ifndef TCG_CPU_OPS_H
>>>>>  #define TCG_CPU_OPS_H
>>>>>  
>>>>> +#include "hw/core/cpu.h"
>>>>
>>>> This include is circular.
>>>
>>> Yes, it's protected though, it was asked that way.
>>
>> Well, in my strong opinion, someone asked incorrectly.  It's "harmless" 
>> because
>> of the protection ifdefs, but it's Wrong because it has the potential to 
>> hide bugs.
>>
>> What is it that you thought you needed from core/cpu.h anyway?
>>
>>>> Are you sure that splitting out hw/core/tcg-cpu-ops.h from hw/core/cpu.h in
>>>> patch 15 is even useful?
>>>
>>> it avoids a huge #ifdef CONFIG_TCG
>>
>> So?  The question should be: is it useful on its own, and I think the answer 
>> to
>> that is clearly not.  Thus it should not pretend to be a standalone header 
>> file.
>>
>>
>> r~
>>
> 
> The whole point of the exercise is to sort out what is tcg specific and only 
> compile it under CONFIG_TCG.
> 
> Having everything inside cpu.h wrapped in a 100 line #ifdef is not 
> particularly readable or discoverable,
> so I think it is actually useful for understanding purposes to have it 
> separate,
> but that said, I don't feel strongly on this, as I intend to improve this in 
> later series.
> 


Should I return this file to the original state (without the extra #includes 
that pretend it to be a standalone header file,
and call it

tcg-cpu-ops.h.inc

?

Ciao,

Claudio