[RFC 16/17] KVM: eventfd: add irq bypass consumer management

Eric Auger
2015-07-02T13:20:06Z

This patch adds the registration/unregistration of an
irq_bypass_consumer on irqfd assignment/deassignment.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
---
virt/kvm/eventfd.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index f3da161..425a47b 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -34,6 +34,7 @@
#include <linux/srcu.h>
#include <linux/slab.h>
#include <linux/seqlock.h>
+#include <linux/irqbypass.h>
#include <trace/events/kvm.h>

#include <kvm/iodev.h>
@@ -93,6 +94,7 @@ struct _irqfd {
struct list_head list;
poll_table pt;
struct work_struct shutdown;
+ struct irq_bypass_consumer *cons;
};

static struct workqueue_struct *irqfd_cleanup_wq;
@@ -429,7 +431,21 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
*/
fdput(f);

- /* irq_bypass_register_consumer(); */
+ irqfd->cons = kzalloc(sizeof(struct irq_bypass_consumer),
+ GFP_KERNEL);
+ if (!irqfd->cons) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+ irqfd->cons->token = (void *)irqfd->eventfd;
+ irqfd->cons->gsi = irqfd->gsi;
+ irqfd->cons->kvm = kvm;
+ irqfd->cons->add_producer = kvm_arch_add_producer;
+ irqfd->cons->del_producer = kvm_arch_del_producer;
+ irqfd->cons->stop_consumer = kvm_arch_stop_consumer;
+ irqfd->cons->resume_consumer = kvm_arch_resume_consumer;
+ ret = irq_bypass_register_consumer(irqfd->cons);
+ WARN_ON(ret);

return 0;

@@ -530,8 +546,6 @@ kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd *args)
struct _irqfd *irqfd, *tmp;
struct eventfd_ctx *eventfd;

- /* irq_bypass_unregister_consumer() */
-
eventfd = eventfd_ctx_fdget(args->fd);
if (IS_ERR(eventfd))
return PTR_ERR(eventfd);
@@ -550,6 +564,8 @@ kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd *args)
irqfd->irq_entry.type = 0;
write_seqcount_end(&irqfd->irq_entry_sc);
irqfd_deactivate(irqfd);
+ irq_bypass_unregister_consumer(irqfd->cons);
+ kfree(irqfd->cons);
}
}

--
1.9.1