On Fri, 25 May 2018 13:37:06 +0200
David Hildenbrand <da...@redhat.com> 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/misc_helper.c b/target/s390x/misc_helper.c
> index 2ef9de1cca..2f5cd6d22a 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);
Would it make sense to cache the class as well?
> + 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);
> +
> + return 0;
> +}
> +
