On Thu, 25 Feb 2021 18:29:14 -0300
Daniel Henrique Barboza <danielhb...@gmail.com> wrote:
> The pSeries machine is using QEMUTimer internals to return the timeout
> in seconds for a timer object, in hw/ppc/spapr.c, function
> spapr_drc_unplug_timeout_remaining_sec().
>
> Create a helper in qemu-timer.c to retrieve the deadline for a QEMUTimer
> object, in ms, to avoid exposing timer internals to the PPC code.
>
> CC: Paolo Bonzini <pbonz...@redhat.com>
> Signed-off-by: Daniel Henrique Barboza <danielhb...@gmail.com>
> ---
>
> This patch is applicable on top of David's ppc-for-6.0.
>
> hw/ppc/spapr_drc.c | 5 ++---
> include/qemu/timer.h | 8 ++++++++
> util/qemu-timer.c | 13 +++++++++++++
> 3 files changed, 23 insertions(+), 3 deletions(-)
>
> diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
> index 8c4997d795..98b626acf9 100644
> --- a/hw/ppc/spapr_drc.c
> +++ b/hw/ppc/spapr_drc.c
> @@ -421,9 +421,8 @@ void spapr_drc_unplug_request(SpaprDrc *drc)
>
> int spapr_drc_unplug_timeout_remaining_sec(SpaprDrc *drc)
> {
> - if (drc->unplug_requested && timer_pending(drc->unplug_timeout_timer)) {
> - return
> (qemu_timeout_ns_to_ms(drc->unplug_timeout_timer->expire_time) -
> - qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL)) / 1000;
> + if (drc->unplug_requested) {
> + return timer_deadline_ms(drc->unplug_timeout_timer) / 1000;
> }
Nice improvement. This also removes a dependency on QEMU_CLOCK_VIRTUAL
that we shouldn't need since we've already passed it to timer_new_ms()
during realize.
It seems that spapr_drc_start_unplug_timeout_timer() ...
static void spapr_drc_start_unplug_timeout_timer(SpaprDrc *drc)
{
SpaprDrcClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
if (drck->unplug_timeout_seconds != 0) {
timer_mod(drc->unplug_timeout_timer,
qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
drck->unplug_timeout_seconds * 1000);
}
}
... could be simplified as well with a timer_mod_deadline_ms() helper,
but this can go to another patch.
>
> return 0;
> diff --git a/include/qemu/timer.h b/include/qemu/timer.h
> index 1678238384..5e76e3f8c2 100644
> --- a/include/qemu/timer.h
> +++ b/include/qemu/timer.h
> @@ -795,6 +795,14 @@ static inline int64_t get_max_clock_jump(void)
> return 60 * NANOSECONDS_PER_SECOND;
> }
>
> +/**
> + * timer_deadline_ms:
> + *
> + * Returns the remaining miliseconds for @timer to expire, or zero
> + * if the timer is no longer pending.
> + */
> +int64_t timer_deadline_ms(QEMUTimer *timer);
> +
> /*
> * Low level clock functions
> */
> diff --git a/util/qemu-timer.c b/util/qemu-timer.c
> index 81c28af517..3a03a63daa 100644
> --- a/util/qemu-timer.c
> +++ b/util/qemu-timer.c
> @@ -243,6 +243,19 @@ int64_t timerlist_deadline_ns(QEMUTimerList *timer_list)
> return delta;
> }
>
> +/*
> + * Returns the time remaining for the deadline, in ms.
> + */
> +int64_t timer_deadline_ms(QEMUTimer *timer)
> +{
> + if (timer_pending(timer)) {
> + return qemu_timeout_ns_to_ms(timer->expire_time) -
> + qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
This is assuming that the timer belongs to the QEMU_CLOCK_VIRTUAL
clock, which looks awkward for a presumably generic function.
Correct clock type can be accessed through ->timer_list :
qemu_clock_get_ms(timer->timer_list->clock->type)
> + }
> +
> + return 0;
> +}
> +
> /* Calculate the soonest deadline across all timerlists attached
> * to the clock. This is used for the icount timeout so we
> * ignore whether or not the clock should be used in deadline
