From: Greg Kroah-Hartman gregkh@linuxfoundation.org
From: Juergen Gross jgross@suse.com
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 --- 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)