Daniil Tatianin <d-tatia...@yandex-team.ru> writes:
> This can be used to force-synchronize the time in guest after a long
> stop-cont pause, which can be useful for serverless-type workload.
>
> Signed-off-by: Daniil Tatianin <d-tatia...@yandex-team.ru>
> ---
> hw/rtc/mc146818rtc.c | 15 +++++++++++++++
> include/hw/rtc/mc146818rtc.h | 1 +
> qapi/misc-target.json | 16 ++++++++++++++++
> 3 files changed, 32 insertions(+)
>
> diff --git a/hw/rtc/mc146818rtc.c b/hw/rtc/mc146818rtc.c
> index f4c1869232..6980a78d5f 100644
> --- a/hw/rtc/mc146818rtc.c
> +++ b/hw/rtc/mc146818rtc.c
> @@ -116,6 +116,21 @@ void qmp_rtc_reset_reinjection(Error **errp)
> }
> }
>
> +void qmp_rtc_notify(Error **errp)
> +{
> + MC146818RtcState *s;
> +
> + /*
> + * See:
> + * https://www.kernel.org/doc/Documentation/virtual/kvm/timekeeping.txt
> + */
> + QLIST_FOREACH(s, &rtc_devices, link) {
> + s->cmos_data[RTC_REG_B] |= REG_B_UIE;
> + s->cmos_data[RTC_REG_C] |= REG_C_IRQF | REG_C_UF;
> + qemu_irq_raise(s->irq);
> + }
> +}
> +
Note for later: qmp_rtc_notify() works on all realized mc146818rtc
devices. Other kinds of RTC devices are silently ignored. Just like
qmp_rtc_reset_reinjection().
> static bool rtc_policy_slew_deliver_irq(MC146818RtcState *s)
> {
> kvm_reset_irq_delivered();
> diff --git a/include/hw/rtc/mc146818rtc.h b/include/hw/rtc/mc146818rtc.h
> index 97cec0b3e8..5229dffbbd 100644
> --- a/include/hw/rtc/mc146818rtc.h
> +++ b/include/hw/rtc/mc146818rtc.h
> @@ -56,5 +56,6 @@ MC146818RtcState *mc146818_rtc_init(ISABus *bus, int
> base_year,
> void mc146818rtc_set_cmos_data(MC146818RtcState *s, int addr, int val);
> int mc146818rtc_get_cmos_data(MC146818RtcState *s, int addr);
> void qmp_rtc_reset_reinjection(Error **errp);
> +void qmp_rtc_notify(Error **errp);
>
> #endif /* HW_RTC_MC146818RTC_H */
> diff --git a/qapi/misc-target.json b/qapi/misc-target.json
> index 4e0a6492a9..20457b0acc 100644
> --- a/qapi/misc-target.json
> +++ b/qapi/misc-target.json
> @@ -19,6 +19,22 @@
##
# @rtc-reset-reinjection:
#
# This command will reset the RTC interrupt reinjection backlog. Can
# be used if another mechanism to synchronize guest time is in effect,
# for example QEMU guest agent's guest-set-time command.
#
# Since: 2.1
#
# Example:
#
# -> { "execute": "rtc-reset-reinjection" }
# <- { "return": {} }
##
> { 'command': 'rtc-reset-reinjection',
> 'if': 'TARGET_I386' }
>
> +##
> +# @rtc-notify:
> +#
> +# Generate an RTC interrupt.
Our QMP command to generate NMIs is called inject-nmi. Call this one
inject-rtc-irq for consistency? rtc-inject-irq?
> +#
> +# Since: 9.1
> +#
> +# Example:
> +#
> +# -> { "execute": "rtc-notify" }
> +# <- { "return": {} }
> +#
> +##
> +{ 'command': 'rtc-notify',
> + 'if': 'TARGET_I386' }
> +
As noted above, both commands silently ignore RTCs other than
mc146818rtc.
They're only available with TARGET_I386.
As long as all machines available with TARGET_I386 can only ever contain
mc146818rtc RTCs, ignoring other RTCs is a non-problem in practice.
Feels a bit fragile to me. Thoughts?
> ##
> # @SevState:
> #
