From 4fa6b9c5dc4134bdeac341d731a87783cc11ca10 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Tue, 17 Jun 2008 15:36:36 -0700 Subject: [PATCH] KVM: ioapic: fix lost interrupt when changing a device's irq The ioapic acknowledge path translates interrupt vectors to irqs. It currently uses a first match algorithm, stopping when it finds the first redirection table entry containing the vector. That fails however if the guest changes the irq to a different line, leaving the old redirection table entry in place (though masked). Result is interrupts not making it to the guest. Fix by always scanning the entire redirection table. Signed-off-by: Avi Kivity --- virt/kvm/ioapic.c | 31 +++++++++++-------------------- 1 file changed, 11 insertions(+), 20 deletions(-) diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index 98778cb69c..1dcf9f3d11 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -269,28 +269,9 @@ void kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level) } } -static int get_eoi_gsi(struct kvm_ioapic *ioapic, int vector) +static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int gsi) { - int i; - - for (i = 0; i < IOAPIC_NUM_PINS; i++) - if (ioapic->redirtbl[i].fields.vector == vector) - return i; - return -1; -} - -void kvm_ioapic_update_eoi(struct kvm *kvm, int vector) -{ - struct kvm_ioapic *ioapic = kvm->arch.vioapic; union ioapic_redir_entry *ent; - int gsi; - - gsi = get_eoi_gsi(ioapic, vector); - if (gsi == -1) { - printk(KERN_WARNING "Can't find redir item for %d EOI\n", - vector); - return; - } ent = &ioapic->redirtbl[gsi]; ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG); @@ -300,6 +281,16 @@ void kvm_ioapic_update_eoi(struct kvm *kvm, int vector) ioapic_deliver(ioapic, gsi); } +void kvm_ioapic_update_eoi(struct kvm *kvm, int vector) +{ + struct kvm_ioapic *ioapic = kvm->arch.vioapic; + int i; + + for (i = 0; i < IOAPIC_NUM_PINS; i++) + if (ioapic->redirtbl[i].fields.vector == vector) + __kvm_ioapic_update_eoi(ioapic, i); +} + static int ioapic_in_range(struct kvm_io_device *this, gpa_t addr) { struct kvm_ioapic *ioapic = (struct kvm_ioapic *)this->private; -- 2.39.5