Re: [qemu-s390x] [PATCH v3 7/9] s390x/tcg: implement SET CLOCK

[Thomas Huth]

On 25.06.2018 13:53, David Hildenbrand wrote:
> This allows a guest to change its TOD. We already take care of updating
> all CKC timers from within S390TODClass.
> 
> Use MO_ALIGN to load the operand manually - this will properly trigger a
> SPECIFICATION exception.
> 
> Signed-off-by: David Hildenbrand <address@hidden>
> ---
>  target/s390x/helper.h      |  1 +
>  target/s390x/insn-data.def |  3 +--
>  target/s390x/misc_helper.c | 16 ++++++++++++++++
>  target/s390x/translate.c   |  9 +++++++++
>  4 files changed, 27 insertions(+), 2 deletions(-)
> 
> diff --git a/target/s390x/helper.h b/target/s390x/helper.h
> index 59cba86a27..97c60ca7bc 100644
> --- a/target/s390x/helper.h
> +++ b/target/s390x/helper.h
> @@ -127,6 +127,7 @@ 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)
>  DEF_HELPER_FLAGS_1(stckc, TCG_CALL_NO_RWG, i64, env)
> diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def
> index 157619403d..5c6f33ed9c 100644
> --- a/target/s390x/insn-data.def
> +++ b/target/s390x/insn-data.def
> @@ -997,8 +997,7 @@
>  /* SET ADDRESS SPACE CONTROL FAST */
>      C(0xb279, SACF,    S,     Z,   0, a2, 0, 0, sacf, 0)
>  /* SET CLOCK */
> -    /* ??? Not implemented - is it necessary? */
> -    C(0xb204, SCK,     S,     Z,   0, 0, 0, 0, 0, 0)
> +    C(0xb204, SCK,     S,     Z,   la2, 0, 0, 0, sck, 0)
>  /* SET CLOCK COMPARATOR */
>      C(0xb206, SCKC,    S,     Z,   0, m2_64a, 0, 0, sckc, 0)
>  /* SET CLOCK PROGRAMMABLE FIELD */
> diff --git a/target/s390x/misc_helper.c b/target/s390x/misc_helper.c
> index 4872bdd774..a223970d1c 100644
> --- a/target/s390x/misc_helper.c
> +++ b/target/s390x/misc_helper.c
> @@ -189,6 +189,22 @@ void tcg_s390_tod_updated(CPUState *cs, run_on_cpu_data 
> opaque)
>      helper_sckc(env, env->ckc);
>  }
>  
> +/* Set Clock */
> +uint32_t HELPER(sck)(CPUS390XState *env, uint64_t tod_low)
> +{
> +    S390TODState *td = s390_get_todstate();
> +    S390TODClass *tdc = S390_TOD_GET_CLASS(td);
> +    S390TOD tod = {
> +        .high = 0,
> +        .low = tod_low,
> +    };
> +
> +    qemu_mutex_lock_iothread();
> +    tdc->set(td, &tod, &error_abort);
> +    qemu_mutex_unlock_iothread();
> +    return 0;
> +}
> +
>  /* Set Tod Programmable Field */
>  void HELPER(sckpf)(CPUS390XState *env, uint64_t r0)
>  {
> diff --git a/target/s390x/translate.c b/target/s390x/translate.c
> index fdfec7feba..57c03cbf58 100644
> --- a/target/s390x/translate.c
> +++ b/target/s390x/translate.c
> @@ -4016,6 +4016,15 @@ static DisasJumpType op_stcke(DisasContext *s, 
> DisasOps *o)
>      return DISAS_NEXT;
>  }
>  
> +static DisasJumpType op_sck(DisasContext *s, DisasOps *o)
> +{
> +    check_privileged(s);
> +    tcg_gen_qemu_ld_i64(o->in1, o->addr1, get_mem_index(s), MO_TEQ | 
> MO_ALIGN);
> +    gen_helper_sck(cc_op, cpu_env, o->in1);
> +    set_cc_static(s);
> +    return DISAS_NEXT;
> +}
> +
>  static DisasJumpType op_sckc(DisasContext *s, DisasOps *o)
>  {
>      check_privileged(s);
> 

Acked-by: Thomas Huth <address@hidden>