Re: [PATCH v3 06/11] tcg: Introduce tb_mark_invalid() and tb_is_invalid()

[Sergey Fedorov <serge.fdrv@gmail.com>]

On 14/07/16 15:53, Alex Bennée wrote:
> Sergey Fedorov <sergey.fedorov@linaro.org> writes:
>
>> From: Sergey Fedorov <serge.fdrv@gmail.com>
>>
>> These functions will be used to make translation block invalidation safe
>> with concurrent lockless lookup in the global hash table.
>>
>> Most targets don't use 'cs_base'; so marking TB as invalid is as simple
>> as assigning -1 to 'cs_base'. SPARC target stores the next program
>> counter into 'cs_base', and -1 is a fine invalid value since PC must bet
>> a multiple of 4 in SPARC. The only odd target is i386, for which a
>> special flag is introduced in place of removed 'HF_SOFTMMU_MASK'.
>>
>> Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
>> Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
>> Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
>> ---
>>  include/exec/exec-all.h  | 10 ++++++++++
>>  target-alpha/cpu.h       | 14 ++++++++++++++
>>  target-arm/cpu.h         | 14 ++++++++++++++
>>  target-cris/cpu.h        | 14 ++++++++++++++
>>  target-i386/cpu.h        | 17 +++++++++++++++++
>>  target-lm32/cpu.h        | 14 ++++++++++++++
>>  target-m68k/cpu.h        | 14 ++++++++++++++
>>  target-microblaze/cpu.h  | 14 ++++++++++++++
>>  target-mips/cpu.h        | 14 ++++++++++++++
>>  target-moxie/cpu.h       | 14 ++++++++++++++
>>  target-openrisc/cpu.h    | 14 ++++++++++++++
>>  target-ppc/cpu.h         | 14 ++++++++++++++
>>  target-s390x/cpu.h       | 14 ++++++++++++++
>>  target-sh4/cpu.h         | 14 ++++++++++++++
>>  target-sparc/cpu.h       | 14 ++++++++++++++
>>  target-sparc/translate.c |  1 +
>>  target-tilegx/cpu.h      | 14 ++++++++++++++
>>  target-tricore/cpu.h     | 14 ++++++++++++++
>>  target-unicore32/cpu.h   | 14 ++++++++++++++
>>  target-xtensa/cpu.h      | 14 ++++++++++++++
>>  20 files changed, 266 insertions(+)
>>
>> diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
>> index db79ab65cebe..61cc3a1fb8f7 100644
>> --- a/include/exec/exec-all.h
>> +++ b/include/exec/exec-all.h
>> @@ -256,6 +256,16 @@ void tb_free(TranslationBlock *tb);
>>  void tb_flush(CPUState *cpu);
>>  void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr);
>>
>> +static inline void tb_mark_invalid(TranslationBlock *tb)
>> +{
>> +    cpu_get_invalid_tb_cpu_state(&tb->pc, &tb->cs_base, &tb->flags);
> Hmmm are we getting something here? Maybe cpu_tb_invalidate_cpu_state?

Just to be similar to cpu_get_tb_cpu_state().

>
>> +}
>> +
>> +static inline bool tb_is_invalid(TranslationBlock *tb)
>> +{
>> +    return cpu_tb_cpu_state_is_invalidated(tb->pc, tb->cs_base, tb->flags);
>> +}
> Also why are we passing three pointers to parts of TranslationBlock? Why
> not just pass tb directly and be done with it?

I'm not sure we want to include exec/exec-all.h in target-*/cpu.h

>
> I'm sure the compiler does something sensible but seems overly verbose
> to me.
>
>> +
>>  #if defined(USE_DIRECT_JUMP)
>>
>>  #if defined(CONFIG_TCG_INTERPRETER)
(snip)
> Otherwise:
>
> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

Kind regards,
Sergey