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xen/events: use a common cpu hotplug hook for event channels

Today only fifo event channels have a cpu hotplug callback. In order
to prepare for more percpu (de)init work move that callback into
events_base.c and add percpu_init() and percpu_deinit() hooks to
struct evtchn_ops.

This is part of XSA-332.

Cc: stable@vger.kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wl@xen.org>
zero-sugar-mainline-defconfig
Juergen Gross 2020-09-13 14:23:02 +02:00
parent c44b849cee
commit 7beb290caa
3 changed files with 47 additions and 21 deletions

View File

@ -34,6 +34,7 @@
#include <linux/irqnr.h>
#include <linux/pci.h>
#include <linux/spinlock.h>
#include <linux/cpuhotplug.h>
#ifdef CONFIG_X86
#include <asm/desc.h>
@ -1830,6 +1831,26 @@ static inline void xen_alloc_callback_vector(void) {}
static bool fifo_events = true;
module_param(fifo_events, bool, 0);
static int xen_evtchn_cpu_prepare(unsigned int cpu)
{
int ret = 0;
if (evtchn_ops->percpu_init)
ret = evtchn_ops->percpu_init(cpu);
return ret;
}
static int xen_evtchn_cpu_dead(unsigned int cpu)
{
int ret = 0;
if (evtchn_ops->percpu_deinit)
ret = evtchn_ops->percpu_deinit(cpu);
return ret;
}
void __init xen_init_IRQ(void)
{
int ret = -EINVAL;
@ -1840,6 +1861,10 @@ void __init xen_init_IRQ(void)
if (ret < 0)
xen_evtchn_2l_init();
cpuhp_setup_state_nocalls(CPUHP_XEN_EVTCHN_PREPARE,
"xen/evtchn:prepare",
xen_evtchn_cpu_prepare, xen_evtchn_cpu_dead);
evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
sizeof(*evtchn_to_irq), GFP_KERNEL);
BUG_ON(!evtchn_to_irq);

View File

@ -385,21 +385,6 @@ static void evtchn_fifo_resume(void)
event_array_pages = 0;
}
static const struct evtchn_ops evtchn_ops_fifo = {
.max_channels = evtchn_fifo_max_channels,
.nr_channels = evtchn_fifo_nr_channels,
.setup = evtchn_fifo_setup,
.bind_to_cpu = evtchn_fifo_bind_to_cpu,
.clear_pending = evtchn_fifo_clear_pending,
.set_pending = evtchn_fifo_set_pending,
.is_pending = evtchn_fifo_is_pending,
.test_and_set_mask = evtchn_fifo_test_and_set_mask,
.mask = evtchn_fifo_mask,
.unmask = evtchn_fifo_unmask,
.handle_events = evtchn_fifo_handle_events,
.resume = evtchn_fifo_resume,
};
static int evtchn_fifo_alloc_control_block(unsigned cpu)
{
void *control_block = NULL;
@ -422,19 +407,36 @@ static int evtchn_fifo_alloc_control_block(unsigned cpu)
return ret;
}
static int xen_evtchn_cpu_prepare(unsigned int cpu)
static int evtchn_fifo_percpu_init(unsigned int cpu)
{
if (!per_cpu(cpu_control_block, cpu))
return evtchn_fifo_alloc_control_block(cpu);
return 0;
}
static int xen_evtchn_cpu_dead(unsigned int cpu)
static int evtchn_fifo_percpu_deinit(unsigned int cpu)
{
__evtchn_fifo_handle_events(cpu, true);
return 0;
}
static const struct evtchn_ops evtchn_ops_fifo = {
.max_channels = evtchn_fifo_max_channels,
.nr_channels = evtchn_fifo_nr_channels,
.setup = evtchn_fifo_setup,
.bind_to_cpu = evtchn_fifo_bind_to_cpu,
.clear_pending = evtchn_fifo_clear_pending,
.set_pending = evtchn_fifo_set_pending,
.is_pending = evtchn_fifo_is_pending,
.test_and_set_mask = evtchn_fifo_test_and_set_mask,
.mask = evtchn_fifo_mask,
.unmask = evtchn_fifo_unmask,
.handle_events = evtchn_fifo_handle_events,
.resume = evtchn_fifo_resume,
.percpu_init = evtchn_fifo_percpu_init,
.percpu_deinit = evtchn_fifo_percpu_deinit,
};
int __init xen_evtchn_fifo_init(void)
{
int cpu = smp_processor_id();
@ -448,9 +450,5 @@ int __init xen_evtchn_fifo_init(void)
evtchn_ops = &evtchn_ops_fifo;
cpuhp_setup_state_nocalls(CPUHP_XEN_EVTCHN_PREPARE,
"xen/evtchn:prepare",
xen_evtchn_cpu_prepare, xen_evtchn_cpu_dead);
return ret;
}

View File

@ -69,6 +69,9 @@ struct evtchn_ops {
void (*handle_events)(unsigned cpu);
void (*resume)(void);
int (*percpu_init)(unsigned int cpu);
int (*percpu_deinit)(unsigned int cpu);
};
extern const struct evtchn_ops *evtchn_ops;