| Message ID | 20201015210318.117386-1-lvivier@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ppc/spapr: re-assert IRQs during event-scan if there are pending | expand |
On Thu, 15 Oct 2020 23:03:18 +0200 Laurent Vivier <lvivier@redhat.com> wrote: > If we hotplug a CPU during the first second of the kernel boot, > the IRQ can be sent to the kernel while the RTAS event handler > is not installed. The event is queued, but the kernel doesn't > collect it and ignores the new CPU. > > As the code relies on edge-triggered IRQ, we can re-assert it > during the event-scan RTAS call if there are still pending > events (as it is already done in check-exception). > > Signed-off-by: Laurent Vivier <lvivier@redhat.com> > --- Any BugId to share ? > hw/ppc/spapr_events.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c > index 1069d0197b4f..1add53547ec3 100644 > --- a/hw/ppc/spapr_events.c > +++ b/hw/ppc/spapr_events.c > @@ -1000,10 +1000,22 @@ static void event_scan(PowerPCCPU *cpu, SpaprMachineState *spapr, > target_ulong args, > uint32_t nret, target_ulong rets) > { > + int i; > if (nargs != 4 || nret != 1) { > rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR); > return; > } > + > + for (i = 0; i < EVENT_CLASS_MAX; i++) { > + if (rtas_event_log_contains(EVENT_CLASS_MASK(i))) { > + const SpaprEventSource *source = > + spapr_event_sources_get_source(spapr->event_sources, i); > + > + g_assert(source->enabled); > + qemu_irq_pulse(spapr_qirq(spapr, source->irq)); > + } > + } > + This looks good but any reason for not putting this in a function called by both event_scan() and check_exception() ? Anyway, this can be done as a follow-up: Reviewed-by: Greg Kurz <groug@kaod.org> > rtas_st(rets, 0, RTAS_OUT_NO_ERRORS_FOUND); > } >
On Thu, Oct 15, 2020 at 11:03:18PM +0200, Laurent Vivier wrote: > If we hotplug a CPU during the first second of the kernel boot, > the IRQ can be sent to the kernel while the RTAS event handler > is not installed. The event is queued, but the kernel doesn't > collect it and ignores the new CPU. > > As the code relies on edge-triggered IRQ, we can re-assert it > during the event-scan RTAS call if there are still pending > events (as it is already done in check-exception). > > Signed-off-by: Laurent Vivier <lvivier@redhat.com> Applied to ppc-for-5.2. > --- > hw/ppc/spapr_events.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c > index 1069d0197b4f..1add53547ec3 100644 > --- a/hw/ppc/spapr_events.c > +++ b/hw/ppc/spapr_events.c > @@ -1000,10 +1000,22 @@ static void event_scan(PowerPCCPU *cpu, SpaprMachineState *spapr, > target_ulong args, > uint32_t nret, target_ulong rets) > { > + int i; > if (nargs != 4 || nret != 1) { > rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR); > return; > } > + > + for (i = 0; i < EVENT_CLASS_MAX; i++) { > + if (rtas_event_log_contains(EVENT_CLASS_MASK(i))) { > + const SpaprEventSource *source = > + spapr_event_sources_get_source(spapr->event_sources, i); > + > + g_assert(source->enabled); > + qemu_irq_pulse(spapr_qirq(spapr, source->irq)); > + } > + } > + > rtas_st(rets, 0, RTAS_OUT_NO_ERRORS_FOUND); > } >
diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c index 1069d0197b4f..1add53547ec3 100644 --- a/hw/ppc/spapr_events.c +++ b/hw/ppc/spapr_events.c @@ -1000,10 +1000,22 @@ static void event_scan(PowerPCCPU *cpu, SpaprMachineState *spapr, target_ulong args, uint32_t nret, target_ulong rets) { + int i; if (nargs != 4 || nret != 1) { rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR); return; } + + for (i = 0; i < EVENT_CLASS_MAX; i++) { + if (rtas_event_log_contains(EVENT_CLASS_MASK(i))) { + const SpaprEventSource *source = + spapr_event_sources_get_source(spapr->event_sources, i); + + g_assert(source->enabled); + qemu_irq_pulse(spapr_qirq(spapr, source->irq)); + } + } + rtas_st(rets, 0, RTAS_OUT_NO_ERRORS_FOUND); }
If we hotplug a CPU during the first second of the kernel boot, the IRQ can be sent to the kernel while the RTAS event handler is not installed. The event is queued, but the kernel doesn't collect it and ignores the new CPU. As the code relies on edge-triggered IRQ, we can re-assert it during the event-scan RTAS call if there are still pending events (as it is already done in check-exception). Signed-off-by: Laurent Vivier <lvivier@redhat.com> --- hw/ppc/spapr_events.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)