From 9957c86d659a4d5a2bed25ccbd3bfc9c3f25e658 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Mon, 30 Jun 2014 20:51:11 +1000 Subject: KVM: Move all accesses to kvm::irq_routing into irqchip.c Now that struct _irqfd does not keep a reference to storage pointed to by the irq_routing field of struct kvm, we can move the statement that updates it out from under the irqfds.lock and put it in kvm_set_irq_routing() instead. That means we then have to take a srcu_read_lock on kvm->irq_srcu around the irqfd_update call in kvm_irqfd_assign(), since holding the kvm->irqfds.lock no longer ensures that that the routing can't change. Combined with changing kvm_irq_map_gsi() and kvm_irq_map_chip_pin() to take a struct kvm * argument instead of the pointer to the routing table, this allows us to to move all references to kvm->irq_routing into irqchip.c. That in turn allows us to move the definition of the kvm_irq_routing_table struct into irqchip.c as well. Signed-off-by: Paul Mackerras Tested-by: Eric Auger Tested-by: Cornelia Huck Signed-off-by: Paolo Bonzini --- virt/kvm/eventfd.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) (limited to 'virt/kvm/eventfd.c') diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index 15fa9488b2d0..f0075ffb0c35 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -278,14 +278,13 @@ irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh, } /* Must be called under irqfds.lock */ -static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd, - struct kvm_irq_routing_table *irq_rt) +static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd) { struct kvm_kernel_irq_routing_entry *e; struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS]; int i, n_entries; - n_entries = kvm_irq_map_gsi(entries, irq_rt, irqfd->gsi); + n_entries = kvm_irq_map_gsi(kvm, entries, irqfd->gsi); write_seqcount_begin(&irqfd->irq_entry_sc); @@ -304,12 +303,12 @@ static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd, static int kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args) { - struct kvm_irq_routing_table *irq_rt; struct _irqfd *irqfd, *tmp; struct fd f; struct eventfd_ctx *eventfd = NULL, *resamplefd = NULL; int ret; unsigned int events; + int idx; irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL); if (!irqfd) @@ -403,9 +402,9 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args) goto fail; } - irq_rt = rcu_dereference_protected(kvm->irq_routing, - lockdep_is_held(&kvm->irqfds.lock)); - irqfd_update(kvm, irqfd, irq_rt); + idx = srcu_read_lock(&kvm->irq_srcu); + irqfd_update(kvm, irqfd); + srcu_read_unlock(&kvm->irq_srcu, idx); list_add_tail(&irqfd->list, &kvm->irqfds.items); @@ -539,20 +538,17 @@ kvm_irqfd_release(struct kvm *kvm) } /* - * Change irq_routing and irqfd. + * Take note of a change in irq routing. * Caller must invoke synchronize_srcu(&kvm->irq_srcu) afterwards. */ -void kvm_irq_routing_update(struct kvm *kvm, - struct kvm_irq_routing_table *irq_rt) +void kvm_irq_routing_update(struct kvm *kvm) { struct _irqfd *irqfd; spin_lock_irq(&kvm->irqfds.lock); - rcu_assign_pointer(kvm->irq_routing, irq_rt); - list_for_each_entry(irqfd, &kvm->irqfds.items, list) - irqfd_update(kvm, irqfd, irq_rt); + irqfd_update(kvm, irqfd); spin_unlock_irq(&kvm->irqfds.lock); } -- cgit v1.2.1