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 <sheng@linux.intel.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

2 files changed, 8 insertions, 3 deletions

diff --git a/arch/ia64/include/asm/kvm_host.h b/arch/ia64/include/asm/kvm_host.h
index 85db124d37f6..04c0b88f7b3a 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 a312c9e9b9ef..8a2b13ff0aff 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;
                 }