diff options
| author | Juergen Gross <jgross@suse.com> | 2021-06-23 16:09:13 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-11 13:48:13 +0300 |
| commit | c75310b5e17d0369fec2ab28c748fccf1c2b626f (patch) | |
| tree | d2df97cee42633cc1d38bbbbebb7f8102b5af1f6 | |
| parent | 5f0185cd37347267ff06dd61cd0131b27f164ac5 (diff) | |
| download | linux-c75310b5e17d0369fec2ab28c748fccf1c2b626f.tar.xz | |
xen/events: reset active flag for lateeoi events later
commit 3de218ff39b9e3f0d453fe3154f12a174de44b25 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: b6622798bc50b62 ("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>
| -rw-r--r-- | drivers/xen/events/events_base.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index b370144682ed..a2f8130e18fe 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -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) |