From 5550af4df179e52753d3a43a788a113ad8cd95cd Mon Sep 17 00:00:00 2001 From: Sheng Yang Date: Wed, 15 Oct 2008 20:15:06 +0800 Subject: KVM: Fix guest shared interrupt with in-kernel irqchip Every call of kvm_set_irq() should offer an irq_source_id, which is allocated by kvm_request_irq_source_id(). Based on irq_source_id, we identify the irq source and implement logical OR for shared level interrupts. The allocated irq_source_id can be freed by kvm_free_irq_source_id(). Currently, we support at most sizeof(unsigned long) different irq sources. [Amit: - rebase to kvm.git HEAD - move definition of KVM_USERSPACE_IRQ_SOURCE_ID to common file - move kvm_request_irq_source_id to the update_irq ioctl] [Xiantao: - Add kvm/ia64 stuff and make it work for kvm/ia64 guests] Signed-off-by: Sheng Yang Signed-off-by: Amit Shah Signed-off-by: Xiantao Zhang Signed-off-by: Avi Kivity --- virt/kvm/irq_comm.c | 42 +++++++++++++++++++++++++++++++++++++++--- virt/kvm/kvm_main.c | 12 ++++++++---- 2 files changed, 47 insertions(+), 7 deletions(-) (limited to 'virt/kvm') diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c index d0169f5e6047..55ad76ee2d09 100644 --- a/virt/kvm/irq_comm.c +++ b/virt/kvm/irq_comm.c @@ -25,15 +25,23 @@ #include "ioapic.h" /* This should be called with the kvm->lock mutex held */ -void kvm_set_irq(struct kvm *kvm, int irq, int level) +void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level) { + unsigned long *irq_state = (unsigned long *)&kvm->arch.irq_states[irq]; + + /* Logical OR for level trig interrupt */ + if (level) + set_bit(irq_source_id, irq_state); + else + clear_bit(irq_source_id, irq_state); + /* Not possible to detect if the guest uses the PIC or the * IOAPIC. So set the bit in both. The guest will ignore * writes to the unused one. */ - kvm_ioapic_set_irq(kvm->arch.vioapic, irq, level); + kvm_ioapic_set_irq(kvm->arch.vioapic, irq, !!(*irq_state)); #ifdef CONFIG_X86 - kvm_pic_set_irq(pic_irqchip(kvm), irq, level); + kvm_pic_set_irq(pic_irqchip(kvm), irq, !!(*irq_state)); #endif } @@ -58,3 +66,31 @@ void kvm_unregister_irq_ack_notifier(struct kvm *kvm, { hlist_del(&kian->link); } + +/* The caller must hold kvm->lock mutex */ +int kvm_request_irq_source_id(struct kvm *kvm) +{ + unsigned long *bitmap = &kvm->arch.irq_sources_bitmap; + int irq_source_id = find_first_zero_bit(bitmap, + sizeof(kvm->arch.irq_sources_bitmap)); + if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) { + printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n"); + irq_source_id = -EFAULT; + } else + set_bit(irq_source_id, bitmap); + return irq_source_id; +} + +void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id) +{ + int i; + + if (irq_source_id <= 0 || + irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) { + printk(KERN_ERR "kvm: IRQ source ID out of range!\n"); + return; + } + for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++) + clear_bit(irq_source_id, &kvm->arch.irq_states[i]); + clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap); +} diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index cf0ab8ed3845..a87f45edfae8 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -105,14 +105,12 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work) */ mutex_lock(&assigned_dev->kvm->lock); kvm_set_irq(assigned_dev->kvm, + assigned_dev->irq_source_id, assigned_dev->guest_irq, 1); mutex_unlock(&assigned_dev->kvm->lock); kvm_put_kvm(assigned_dev->kvm); } -/* FIXME: Implement the OR logic needed to make shared interrupts on - * this line behave properly - */ static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id) { struct kvm_assigned_dev_kernel *assigned_dev = @@ -134,7 +132,7 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian) dev = container_of(kian, struct kvm_assigned_dev_kernel, ack_notifier); - kvm_set_irq(dev->kvm, dev->guest_irq, 0); + kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0); enable_irq(dev->host_irq); } @@ -146,6 +144,7 @@ static void kvm_free_assigned_device(struct kvm *kvm, free_irq(assigned_dev->host_irq, (void *)assigned_dev); kvm_unregister_irq_ack_notifier(kvm, &assigned_dev->ack_notifier); + kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id); if (cancel_work_sync(&assigned_dev->interrupt_work)) /* We had pending work. That means we will have to take @@ -215,6 +214,11 @@ static int kvm_vm_ioctl_assign_irq(struct kvm *kvm, match->ack_notifier.gsi = assigned_irq->guest_irq; match->ack_notifier.irq_acked = kvm_assigned_dev_ack_irq; kvm_register_irq_ack_notifier(kvm, &match->ack_notifier); + r = kvm_request_irq_source_id(kvm); + if (r < 0) + goto out_release; + else + match->irq_source_id = r; /* Even though this is PCI, we don't want to use shared * interrupts. Sharing host devices with guest-assigned devices -- cgit v1.2.3