Re: [PATCH 2/7] xen/events: don't unmask an event channel when an eoi is pending

Jan Beulich
2021-02-08T10:23:24Z

On 06.02.2021 11:49, Juergen Gross wrote:
> @@ -1798,6 +1818,29 @@ static void mask_ack_dynirq(struct irq_data *data)
> ack_dynirq(data);
> }
>
> +static void lateeoi_ack_dynirq(struct irq_data *data)
> +{
> + struct irq_info *info = info_for_irq(data->irq);
> + evtchn_port_t evtchn = info ? info->evtchn : 0;
> +
> + if (VALID_EVTCHN(evtchn)) {
> + info->eoi_pending = true;
> + mask_evtchn(evtchn);
> + }
> +}
> +
> +static void lateeoi_mask_ack_dynirq(struct irq_data *data)
> +{
> + struct irq_info *info = info_for_irq(data->irq);
> + evtchn_port_t evtchn = info ? info->evtchn : 0;
> +
> + if (VALID_EVTCHN(evtchn)) {
> + info->masked = true;
> + info->eoi_pending = true;
> + mask_evtchn(evtchn);
> + }
> +}
> +
> static int retrigger_dynirq(struct irq_data *data)
> {
> evtchn_port_t evtchn = evtchn_from_irq(data->irq);
> @@ -2023,8 +2066,8 @@ static struct irq_chip xen_lateeoi_chip __read_mostly = {
> .irq_mask = disable_dynirq,
> .irq_unmask = enable_dynirq,
>
> - .irq_ack = mask_ack_dynirq,
> - .irq_mask_ack = mask_ack_dynirq,
> + .irq_ack = lateeoi_ack_dynirq,
> + .irq_mask_ack = lateeoi_mask_ack_dynirq,
>
> .irq_set_affinity = set_affinity_irq,
> .irq_retrigger = retrigger_dynirq,
>

Unlike the prior handler the two new ones don't call ack_dynirq()
anymore, and the description doesn't give a hint towards this
difference. As a consequence, clear_evtchn() also doesn't get
called anymore - patch 3 adds the calls, but claims an older
commit to have been at fault. _If_ ack_dynirq() indeed isn't to
be called here, shouldn't the clear_evtchn() calls get added
right here?

Jan