Re: [qemu-s390x] [PATCH for-4.0 2/2] target/s390x: Implement STCK et al for CONFIG_USER_ONLY

[Richard Henderson]

On 12/3/18 12:19 AM, Thomas Huth wrote:
> On 2018-11-30 20:22, Richard Henderson wrote:
>> This is a non-privileged instruction that was only implemented
>> for system mode.  However, the stck instruction is used by glibc,
>> so this was causing SIGILL for programs run under debian stretch.
>>
>> Signed-off-by: Richard Henderson <address@hidden>
>> ---
>>  target/s390x/helper.h      |  2 +-
>>  target/s390x/misc_helper.c | 13 ++++++++++++-
>>  target/s390x/translate.c   |  2 ++
>>  target/s390x/insn-data.def | 11 ++++++-----
>>  4 files changed, 21 insertions(+), 7 deletions(-)
>>
>> diff --git a/target/s390x/helper.h b/target/s390x/helper.h
>> index 018e9dd414..6260b50496 100644
>> --- a/target/s390x/helper.h
>> +++ b/target/s390x/helper.h
>> @@ -121,13 +121,13 @@ DEF_HELPER_4(cu41, i32, env, i32, i32, i32)
>>  DEF_HELPER_4(cu42, i32, env, i32, i32, i32)
>>  DEF_HELPER_5(msa, i32, env, i32, i32, i32, i32)
>>  DEF_HELPER_FLAGS_1(stpt, TCG_CALL_NO_RWG, i64, env)
>> +DEF_HELPER_FLAGS_1(stck, TCG_CALL_NO_RWG_SE, i64, env)
>>  
>>  #ifndef CONFIG_USER_ONLY
>>  DEF_HELPER_3(servc, i32, env, i64, i64)
>>  DEF_HELPER_4(diag, void, env, i32, i32, i32)
>>  DEF_HELPER_3(load_psw, noreturn, env, i64, i64)
>>  DEF_HELPER_FLAGS_2(spx, TCG_CALL_NO_RWG, void, env, i64)
>> -DEF_HELPER_FLAGS_1(stck, TCG_CALL_NO_RWG_SE, i64, env)
>>  DEF_HELPER_FLAGS_2(sck, TCG_CALL_NO_RWG, i32, env, i64)
>>  DEF_HELPER_FLAGS_2(sckc, TCG_CALL_NO_RWG, void, env, i64)
>>  DEF_HELPER_FLAGS_2(sckpf, TCG_CALL_NO_RWG, void, env, i64)
>> diff --git a/target/s390x/misc_helper.c b/target/s390x/misc_helper.c
>> index 3f91579570..c2940afecb 100644
>> --- a/target/s390x/misc_helper.c
>> +++ b/target/s390x/misc_helper.c
>> @@ -76,8 +76,19 @@ uint64_t HELPER(stpt)(CPUS390XState *env)
>>  #endif
>>  }
>>  
>> -#ifndef CONFIG_USER_ONLY
>> +#ifdef CONFIG_USER_ONLY
>> +/* Store Clock */
>> +uint64_t HELPER(stck)(CPUS390XState *env)
>> +{
>> +    struct timespec ts;
>> +    uint64_t ms;
> 
> May I suggest "us" for microseconds? "ms" makes me thing of
> "milliseconds"...

Oops, think-o.

>> +    clock_gettime(CLOCK_REALTIME, &ts);
>> +    ms = (ts.tv_nsec / 1000) + (ts.tv_sec * 100000ull);
>> +
>> +    return TOD_UNIX_EPOCH + ms;
>> +}
> 
> Don't you need to shift the value around a little bit for getting the
> right format of the TOD clock? The microseconds are not starting with
> the lowest bit, the TOD clock has a higher resolution. See also the
> time2tod() macro in include/hw/s390x/tod.h ...

That's for STCKE, which does use this routine and shift the result around.


r~