From 908940c92fb916146a7ce24bc41a18125967c54a Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Wed, 3 Feb 2021 16:24:42 +0100 Subject: [PATCH 1/2] xen/events: reset affinity of 2-level event initially 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. 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 Signed-off-by: Juergen Gross --- drivers/xen/events/events_2l.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/xen/events/events_2l.c b/drivers/xen/events/events_2l.c index da87f3a1e351..23217940144a 100644 --- a/drivers/xen/events/events_2l.c +++ b/drivers/xen/events/events_2l.c @@ -47,6 +47,16 @@ static unsigned evtchn_2l_max_channels(void) return EVTCHN_2L_NR_CHANNELS; } +static int evtchn_2l_setup(evtchn_port_t evtchn) +{ + unsigned int cpu; + + for_each_online_cpu(cpu) + clear_bit(evtchn, BM(per_cpu(cpu_evtchn_mask, cpu))); + + return 0; +} + static void evtchn_2l_bind_to_cpu(evtchn_port_t evtchn, unsigned int cpu, unsigned int old_cpu) { @@ -355,9 +365,18 @@ 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, + .setup = evtchn_2l_setup, .bind_to_cpu = evtchn_2l_bind_to_cpu, .clear_pending = evtchn_2l_clear_pending, .set_pending = evtchn_2l_set_pending, @@ -367,6 +386,7 @@ 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) -- 2.26.2