Messages in this thread | | | Subject | Re: [PATCH v2 1/8] xen/events: reset affinity of 2-level event when tearing it down | From | Julien Grall <> | Date | Sun, 14 Feb 2021 21:17:57 +0000 |
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Hi Juergen,
On 11/02/2021 10:16, Juergen Gross wrote: > 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>
Cheers,
> --- > V2: > - reset affinity when tearing down the event (Julien Grall) > --- > 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(+) > > diff --git a/drivers/xen/events/events_2l.c b/drivers/xen/events/events_2l.c > index da87f3a1e351..a7f413c5c190 100644 > --- a/drivers/xen/events/events_2l.c > +++ b/drivers/xen/events/events_2l.c > @@ -47,6 +47,11 @@ 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(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_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 e850f79351cb..6c539db81f8f 100644 > --- 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(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; > channels_on_cpu_dec(info); > } > diff --git a/drivers/xen/events/events_internal.h b/drivers/xen/events/events_internal.h > index 0a97c0549db7..18a4090d0709 100644 > --- 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(evtchn_port_t evtchn) > 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) >
-- Julien Grall
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