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

[Thomas Huth]

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"...

> +    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 ...

 Thomas