xen/events: reset affinity of 2-level event when tearing it down

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@vger.kernel.org
Reported-by: Julien Grall <julien@xen.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Link: https://lore.kernel.org/r/20210306161833.4552-2-jgross@suse.com
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/xen/events/events_2l.c b/drivers/xen/events/events_2l.c
index c31c08a708be59b2c954277160ab6573ee2f24ff..fa9c528d3598654a558a4de171d1baf508e10fd7 100644 (file)
--- a/drivers/xen/events/events_2l.c
+++ b/drivers/xen/events/events_2l.c
@@ -46,6 +46,11 @@ static unsigned evtchn_2l_max_channels(void)
        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(struct irq_info *info, unsigned cpu)
 {
        clear_bit(info->evtchn, BM(per_cpu(cpu_evtchn_mask, info->cpu)));
@@ -353,9 +358,18 @@ 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,
@@ -365,6 +379,7 @@ static const struct evtchn_ops evtchn_ops_2l = {
        .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)

diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 5308bc1e0189dac33ffd8e62685b6c1ba09ebf98..206fe9e30d3c85d70f0dc2e24ab7d8d630bca79a 100644 (file)
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -286,6 +286,7 @@ static int xen_irq_info_pirq_setup(unsigned irq,
 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;
 }
 

diff --git a/drivers/xen/events/events_internal.h b/drivers/xen/events/events_internal.h
index b9b4f59198930dbc185680ed2438c989ba85d770..f5fba722432fbee4b710541e68e61347aac150f5 100644 (file)
--- a/drivers/xen/events/events_internal.h
+++ b/drivers/xen/events/events_internal.h
@@ -67,6 +67,7 @@ struct evtchn_ops {
        unsigned (*nr_channels)(void);
 
        int (*setup)(struct irq_info *info);
+       void (*remove)(evtchn_port_t port, unsigned int cpu);
        void (*bind_to_cpu)(struct irq_info *info, unsigned cpu);
 
        void (*clear_pending)(unsigned port);
@@ -109,6 +110,13 @@ static inline int xen_evtchn_port_setup(struct irq_info *info)
        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(struct irq_info *info,
                                               unsigned cpu)
 {