This is a note to let you know that I've just added the patch titled
xen/events: reset affinity of 2-level event when tearing it down
to the 5.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xen-events-reset-affinity-of-2-level-event-when-tearing-it-down.patch
and it can be found in the queue-5.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9e77d96b8e2724ed00380189f7b0ded61113b39f Mon Sep 17 00:00:00 2001
From: Juergen Gross <jgross@xxxxxxxx>
Date: Sat, 6 Mar 2021 17:18:31 +0100
Subject: xen/events: reset affinity of 2-level event when tearing it down
From: Juergen Gross <jgross@xxxxxxxx>
commit 9e77d96b8e2724ed00380189f7b0ded61113b39f upstream.
When creating a new event channel with 2-level events the affinity
needs to be reset initially in order to avoid using an old affinity
from earlier usage of the event channel port. So when tearing an event
channel down reset all affinity bits.
The same applies to the affinity when onlining a vcpu: all old
affinity settings for this vcpu must be reset. As percpu events get
initialized before the percpu event channel hook is called,
resetting of the affinities happens after offlining a vcpu (this is
working, as initial percpu memory is zeroed out).
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Julien Grall <julien@xxxxxxx>
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210306161833.4552-2-jgross@xxxxxxxx
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/xen/events/events_2l.c | 15 +++++++++++++++
drivers/xen/events/events_base.c | 1 +
drivers/xen/events/events_internal.h | 8 ++++++++
3 files changed, 24 insertions(+)
--- a/drivers/xen/events/events_2l.c
+++ b/drivers/xen/events/events_2l.c
@@ -47,6 +47,11 @@ static unsigned evtchn_2l_max_channels(v
return EVTCHN_2L_NR_CHANNELS;
}
+static void evtchn_2l_remove(evtchn_port_t evtchn, unsigned int cpu)
+{
+ clear_bit(evtchn, BM(per_cpu(cpu_evtchn_mask, cpu)));
+}
+
static void evtchn_2l_bind_to_cpu(evtchn_port_t evtchn, unsigned int cpu,
unsigned int old_cpu)
{
@@ -355,9 +360,18 @@ static void evtchn_2l_resume(void)
EVTCHN_2L_NR_CHANNELS/BITS_PER_EVTCHN_WORD);
}
+static int evtchn_2l_percpu_deinit(unsigned int cpu)
+{
+ memset(per_cpu(cpu_evtchn_mask, cpu), 0, sizeof(xen_ulong_t) *
+ EVTCHN_2L_NR_CHANNELS/BITS_PER_EVTCHN_WORD);
+
+ return 0;
+}
+
static const struct evtchn_ops evtchn_ops_2l = {
.max_channels = evtchn_2l_max_channels,
.nr_channels = evtchn_2l_max_channels,
+ .remove = evtchn_2l_remove,
.bind_to_cpu = evtchn_2l_bind_to_cpu,
.clear_pending = evtchn_2l_clear_pending,
.set_pending = evtchn_2l_set_pending,
@@ -367,6 +381,7 @@ static const struct evtchn_ops evtchn_op
.unmask = evtchn_2l_unmask,
.handle_events = evtchn_2l_handle_events,
.resume = evtchn_2l_resume,
+ .percpu_deinit = evtchn_2l_percpu_deinit,
};
void __init xen_evtchn_2l_init(void)
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -368,6 +368,7 @@ static int xen_irq_info_pirq_setup(unsig
static void xen_irq_info_cleanup(struct irq_info *info)
{
set_evtchn_to_irq(info->evtchn, -1);
+ xen_evtchn_port_remove(info->evtchn, info->cpu);
info->evtchn = 0;
channels_on_cpu_dec(info);
}
--- a/drivers/xen/events/events_internal.h
+++ b/drivers/xen/events/events_internal.h
@@ -14,6 +14,7 @@ struct evtchn_ops {
unsigned (*nr_channels)(void);
int (*setup)(evtchn_port_t port);
+ void (*remove)(evtchn_port_t port, unsigned int cpu);
void (*bind_to_cpu)(evtchn_port_t evtchn, unsigned int cpu,
unsigned int old_cpu);
@@ -54,6 +55,13 @@ static inline int xen_evtchn_port_setup(
return 0;
}
+static inline void xen_evtchn_port_remove(evtchn_port_t evtchn,
+ unsigned int cpu)
+{
+ if (evtchn_ops->remove)
+ evtchn_ops->remove(evtchn, cpu);
+}
+
static inline void xen_evtchn_port_bind_to_cpu(evtchn_port_t evtchn,
unsigned int cpu,
unsigned int old_cpu)
Patches currently in stable-queue which might be from jgross@xxxxxxxx are
queue-5.11/xen-events-don-t-unmask-an-event-channel-when-an-eoi-is-pending.patch
queue-5.11/xen-events-reset-affinity-of-2-level-event-when-tearing-it-down.patch
queue-5.11/xen-events-avoid-handling-the-same-event-on-two-cpus-at-the-same-time.patch
