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xen/events: reset active flag for lateeoi events later

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commit 3de218ff39 upstream.

In order to avoid a race condition for user events when changing
cpu affinity reset the active flag only when EOI-ing the event.

This is working fine as all user events are lateeoi events. Note that
lateeoi_ack_mask_dynirq() is not modified as there is no explicit call
to xen_irq_lateeoi() expected later.

Cc: stable@vger.kernel.org
Reported-by: Julien Grall <julien@xen.org>
Fixes: b6622798bc ("xen/events: avoid handling the same event on two cpus at the same time")
Tested-by: Julien Grall <julien@xen.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrvsky@oracle.com>
Link: https://lore.kernel.org/r/20210623130913.9405-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Juergen Gross 2021-06-23 15:09:13 +02:00 committed by Greg Kroah-Hartman
parent 6e2a98bc90
commit cda326e503
1 changed files with 19 additions and 4 deletions
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23
drivers/xen/events/events_base.c
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@ -524,6 +524,9 @@ static void xen_irq_lateeoi_locked(struct irq_info *info, bool spurious)
}
info->eoi_time = 0;
/* is_active hasn't been reset yet, do it now. */
smp_store_release(&info->is_active, 0);
do_unmask(info, EVT_MASK_REASON_EOI_PENDING);
}
@ -1780,10 +1783,22 @@ 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)) {
do_mask(info, EVT_MASK_REASON_EOI_PENDING);
ack_dynirq(data);
}
if (!VALID_EVTCHN(evtchn))
return;
do_mask(info, EVT_MASK_REASON_EOI_PENDING);
if (unlikely(irqd_is_setaffinity_pending(data)) &&
likely(!irqd_irq_disabled(data))) {
do_mask(info, EVT_MASK_REASON_TEMPORARY);
clear_evtchn(evtchn);
irq_move_masked_irq(data);
do_unmask(info, EVT_MASK_REASON_TEMPORARY);
} else
clear_evtchn(evtchn);
}
static void lateeoi_mask_ack_dynirq(struct irq_data *data)