On 20.06.2018 12:08, 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 <da...@redhat.com>
> ---
> target/s390x/helper.h | 1 +
> target/s390x/insn-data.def | 3 +--
> target/s390x/misc_helper.c | 19 +++++++++++++++++++
> target/s390x/translate.c | 9 +++++++++
> 4 files changed, 30 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 d5f9f5e1d3..c9712b9476 100644
> --- a/target/s390x/misc_helper.c
> +++ b/target/s390x/misc_helper.c
> @@ -191,6 +191,25 @@ 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_tod();
> + S390TODClass *tdc = S390_TOD_GET_CLASS(td);
> + S390TOD tod = {
> + .high = 0,
> + .low = tod_low,
> + };
> + Error *err = NULL;
> +
> + qemu_mutex_lock_iothread();
> + tdc->set(td, &tod, &err);
> + qemu_mutex_unlock_iothread();
> + g_assert(!err);
I know it currently can't happen, but still, I think it would be nicer
to use CC3 to tell the guest that something went wrong with the clock,
instead of abort QEMU here.
Thomas
