From 5550af4df179e52753d3a43a788a113ad8cd95cd Mon Sep 17 00:00:00 2001 From: Sheng Yang Date: Wed, 15 Oct 2008 20:15:06 +0800 Subject: [PATCH] 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 --- arch/ia64/include/asm/kvm_host.h | 3 +++ arch/ia64/kvm/kvm-ia64.c | 8 +++++--- arch/x86/include/asm/kvm_host.h | 3 +++ arch/x86/kvm/i8254.c | 11 +++++++++-- arch/x86/kvm/i8254.h | 1 + arch/x86/kvm/x86.c | 6 +++++- include/linux/kvm_host.h | 7 ++++++- virt/kvm/irq_comm.c | 42 +++++++++++++++++++++++++++++++++++++--- virt/kvm/kvm_main.c | 12 ++++++++---- 9 files changed, 79 insertions(+), 14 deletions(-) diff --git a/arch/ia64/include/asm/kvm_host.h b/arch/ia64/include/asm/kvm_host.h index 85db124..04c0b88 100644 --- a/arch/ia64/include/asm/kvm_host.h +++ b/arch/ia64/include/asm/kvm_host.h @@ -417,6 +417,9 @@ struct kvm_arch { struct list_head assigned_dev_head; struct dmar_domain *intel_iommu_domain; struct hlist_head irq_ack_notifier_list; + + unsigned long irq_sources_bitmap; + unsigned long irq_states[KVM_IOAPIC_NUM_PINS]; }; union cpuid3_t { diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index a312c9e..8a2b13f 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -778,6 +778,9 @@ static void kvm_init_vm(struct kvm *kvm) kvm_build_io_pmt(kvm); INIT_LIST_HEAD(&kvm->arch.assigned_dev_head); + + /* Reserve bit 0 of irq_sources_bitmap for userspace irq source */ + set_bit(KVM_USERSPACE_IRQ_SOURCE_ID, &kvm->arch.irq_sources_bitmap); } struct kvm *kvm_arch_create_vm(void) @@ -941,9 +944,8 @@ long kvm_arch_vm_ioctl(struct file *filp, goto out; if (irqchip_in_kernel(kvm)) { mutex_lock(&kvm->lock); - kvm_ioapic_set_irq(kvm->arch.vioapic, - irq_event.irq, - irq_event.level); + kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, + irq_event.irq, irq_event.level); mutex_unlock(&kvm->lock); r = 0; } diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 65679d0..8346be8 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -364,6 +364,9 @@ struct kvm_arch{ struct page *ept_identity_pagetable; bool ept_identity_pagetable_done; + + unsigned long irq_sources_bitmap; + unsigned long irq_states[KVM_IOAPIC_NUM_PINS]; }; struct kvm_vm_stat { diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c index 11c6725..8772dc9 100644 --- a/arch/x86/kvm/i8254.c +++ b/arch/x86/kvm/i8254.c @@ -545,6 +545,12 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm) if (!pit) return NULL; + mutex_lock(&kvm->lock); + pit->irq_source_id = kvm_request_irq_source_id(kvm); + mutex_unlock(&kvm->lock); + if (pit->irq_source_id < 0) + return NULL; + mutex_init(&pit->pit_state.lock); mutex_lock(&pit->pit_state.lock); spin_lock_init(&pit->pit_state.inject_lock); @@ -587,6 +593,7 @@ void kvm_free_pit(struct kvm *kvm) mutex_lock(&kvm->arch.vpit->pit_state.lock); timer = &kvm->arch.vpit->pit_state.pit_timer.timer; hrtimer_cancel(timer); + kvm_free_irq_source_id(kvm, kvm->arch.vpit->irq_source_id); mutex_unlock(&kvm->arch.vpit->pit_state.lock); kfree(kvm->arch.vpit); } @@ -595,8 +602,8 @@ void kvm_free_pit(struct kvm *kvm) static void __inject_pit_timer_intr(struct kvm *kvm) { mutex_lock(&kvm->lock); - kvm_set_irq(kvm, 0, 1); - kvm_set_irq(kvm, 0, 0); + kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1); + kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0); mutex_unlock(&kvm->lock); } diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h index e436d49..4178022 100644 --- a/arch/x86/kvm/i8254.h +++ b/arch/x86/kvm/i8254.h @@ -44,6 +44,7 @@ struct kvm_pit { struct kvm_io_device speaker_dev; struct kvm *kvm; struct kvm_kpit_state pit_state; + int irq_source_id; }; #define KVM_PIT_BASE_ADDRESS 0x40 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 4f0677d..f1f8ff2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1742,7 +1742,8 @@ long kvm_arch_vm_ioctl(struct file *filp, goto out; if (irqchip_in_kernel(kvm)) { mutex_lock(&kvm->lock); - kvm_set_irq(kvm, irq_event.irq, irq_event.level); + kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, + irq_event.irq, irq_event.level); mutex_unlock(&kvm->lock); r = 0; } @@ -4013,6 +4014,9 @@ struct kvm *kvm_arch_create_vm(void) INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); INIT_LIST_HEAD(&kvm->arch.assigned_dev_head); + /* Reserve bit 0 of irq_sources_bitmap for userspace irq source */ + set_bit(KVM_USERSPACE_IRQ_SOURCE_ID, &kvm->arch.irq_sources_bitmap); + return kvm; } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 3833c48..bb92be2 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -37,6 +37,8 @@ #define KVM_REQ_UNHALT 6 #define KVM_REQ_MMU_SYNC 7 +#define KVM_USERSPACE_IRQ_SOURCE_ID 0 + struct kvm_vcpu; extern struct kmem_cache *kvm_vcpu_cache; @@ -306,15 +308,18 @@ struct kvm_assigned_dev_kernel { int host_irq; int guest_irq; int irq_requested; + int irq_source_id; struct pci_dev *dev; struct kvm *kvm; }; -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); void kvm_notify_acked_irq(struct kvm *kvm, unsigned gsi); 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); +int kvm_request_irq_source_id(struct kvm *kvm); +void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id); #ifdef CONFIG_DMAR int kvm_iommu_map_pages(struct kvm *kvm, gfn_t base_gfn, diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c index d0169f5..55ad76e 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 cf0ab8e..a87f45e 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 -- 1.8.2.3