lkml.org 
[lkml]   [2012]   [Sep]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v10 1/2] kvm: Provide pre-locked setup to irq ack notifier
Date
This enables better integration into irqfd setup where we can adjust
our lock ordering to hold irq_lock, making these callable and avoiding
irq source ID races.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---

include/linux/kvm_host.h | 4 ++++
virt/kvm/irq_comm.c | 18 ++++++++++++++++--
2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index b70b48b..84f6950 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -628,8 +628,12 @@ int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level);
int kvm_set_msi(struct kvm_kernel_irq_routing_entry *irq_entry, struct kvm *kvm,
int irq_source_id, int level);
void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin);
+void __kvm_register_irq_ack_notifier(struct kvm *kvm,
+ struct kvm_irq_ack_notifier *kian);
void kvm_register_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian);
+void __kvm_unregister_irq_ack_notifier(struct kvm *kvm,
+ struct kvm_irq_ack_notifier *kian);
void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian);
int kvm_request_irq_source_id(struct kvm *kvm);
diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index 83402d7..dd0cbf6 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -191,19 +191,33 @@ void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
rcu_read_unlock();
}

+/* hold kvm->irq_lock */
+void __kvm_register_irq_ack_notifier(struct kvm *kvm,
+ struct kvm_irq_ack_notifier *kian)
+{
+ hlist_add_head_rcu(&kian->link, &kvm->irq_ack_notifier_list);
+}
+
void kvm_register_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian)
{
mutex_lock(&kvm->irq_lock);
- hlist_add_head_rcu(&kian->link, &kvm->irq_ack_notifier_list);
+ __kvm_register_irq_ack_notifier(kvm, kian);
mutex_unlock(&kvm->irq_lock);
}

+/* hold kvm->irq_lock and wait for rcu grace period */
+void __kvm_unregister_irq_ack_notifier(struct kvm *kvm,
+ struct kvm_irq_ack_notifier *kian)
+{
+ hlist_del_init_rcu(&kian->link);
+}
+
void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian)
{
mutex_lock(&kvm->irq_lock);
- hlist_del_init_rcu(&kian->link);
+ __kvm_unregister_irq_ack_notifier(kvm, kian);
mutex_unlock(&kvm->irq_lock);
synchronize_rcu();
}


\
 
 \ /
  Last update: 2012-09-18 05:41    [W:0.097 / U:0.164 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site