Re: [PATCH v5 30/33] target-arm/cpu: don't reset TLB structures, use cputlb to do it

["Alex Bennée" <alex.bennee@linaro.org>]

Richard Henderson <rth@twiddle.net> writes:

> On 10/27/2016 08:10 AM, Alex Bennée wrote:
>> cputlb owns the TLB entries and knows how to safely update them in
>> MTTCG.
>>
>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>> ---
>>  target-arm/cpu.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/target-arm/cpu.c b/target-arm/cpu.c
>> index 1b9540e..ff8c594 100644
>> --- a/target-arm/cpu.c
>> +++ b/target-arm/cpu.c
>> @@ -121,7 +121,13 @@ static void arm_cpu_reset(CPUState *s)
>>
>>      acc->parent_reset(s);
>>
>> +#ifdef CONFIG_SOFTMMU
>> +    memset(env, 0, offsetof(CPUARMState, tlb_table));
>> +    tlb_flush(s, 0);
>> +#else
>>      memset(env, 0, offsetof(CPUARMState, features));
>> +#endif
>> +
>
> Why special case this for softmmu?

I didn't want to move cpu->features to the other side of CPU_COMMON in
cpu.h as there is an explicit statement about being reset. Adding
another variable just to be an endpoint of a memset also seemed
sub-optimal.

> And don't we (or if not, shouldn't we)
> handle the tlb_flush generically for reset?

Probably. tlb_flush seems to be one of those things liberally sprinkled
in the arch code for all sorts of things but certainly cpu_reset is one
we could make the call from generic code.

>
>
> r~


--
Alex Bennée