On 2021-02-06 10:49, Juergen Gross wrote:
An event channel should be kept masked when an eoi is pending for it. When being migrated to another cpu it might be unmasked, though.
In order to avoid this keep two different flags for each event channel to be able to distinguish "normal" masking/unmasking from eoi related masking/unmasking. The event channel should only be able to generate an interrupt if both flags are cleared.
Cc: stable@vger.kernel.org Fixes: 54c9de89895e0a36047 ("xen/events: add a new late EOI evtchn framework") Reported-by: Julien Grall julien@xen.org Signed-off-by: Juergen Gross jgross@suse.com
...> +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);- }
+}
Doesn't this (and the one below) need a call to clear_evtchn() to actually ack the pending event? Otherwise I can't see what clears the pending bit.
I tested out this patch but processes using the userspace evtchn device did not work very well without the clear_evtchn() call.
Ross
+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);- }
+}