From 1a577b72475d161b6677c05abe57301362023bb2 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Thu, 19 Jul 2012 13:45:20 +0300 Subject: KVM: fix race with level interrupts When more than 1 source id is in use for the same GSI, we have the following race related to handling irq_states race: CPU 0 clears bit 0. CPU 0 read irq_state as 0. CPU 1 sets level to 1. CPU 1 calls kvm_ioapic_set_irq(1). CPU 0 calls kvm_ioapic_set_irq(0). Now ioapic thinks the level is 0 but irq_state is not 0. Fix by performing all irq_states bitmap handling under pic/ioapic lock. This also removes the need for atomics with irq_states handling. Reported-by: Gleb Natapov Signed-off-by: Michael S. Tsirkin Signed-off-by: Marcelo Tosatti --- virt/kvm/ioapic.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'virt/kvm/ioapic.h') diff --git a/virt/kvm/ioapic.h b/virt/kvm/ioapic.h index 32872a09b63f..a30abfe6ed16 100644 --- a/virt/kvm/ioapic.h +++ b/virt/kvm/ioapic.h @@ -74,7 +74,9 @@ void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode); bool kvm_ioapic_handles_vector(struct kvm *kvm, int vector); int kvm_ioapic_init(struct kvm *kvm); void kvm_ioapic_destroy(struct kvm *kvm); -int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level); +int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id, + int level); +void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id); void kvm_ioapic_reset(struct kvm_ioapic *ioapic); int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src, struct kvm_lapic_irq *irq); -- cgit