KVM: irqfd
KVM provides a complete virtual system environment for guests, including
support for injecting interrupts modeled after the real exception/interrupt
facilities present on the native platform (such as the IDT on x86).
Virtual interrupts can come from a variety of sources (emulated devices,
pass-through devices, etc) but all must be injected to the guest via
the KVM infrastructure. This patch adds a new mechanism to inject a specific
interrupt to a guest using a decoupled eventfd mechnanism: Any legal signal
on the irqfd (using eventfd semantics from either userspace or kernel) will
translate into an injected interrupt in the guest at the next available
interrupt window.
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2884baf..dee321e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -986,6 +986,7 @@
spin_lock_init(&kvm->mmu_lock);
spin_lock_init(&kvm->requests_lock);
kvm_io_bus_init(&kvm->pio_bus);
+ kvm_irqfd_init(kvm);
mutex_init(&kvm->lock);
kvm_io_bus_init(&kvm->mmio_bus);
init_rwsem(&kvm->slots_lock);
@@ -1071,6 +1072,8 @@
{
struct kvm *kvm = filp->private_data;
+ kvm_irqfd_release(kvm);
+
kvm_put_kvm(kvm);
return 0;
}
@@ -2222,6 +2225,15 @@
}
#endif
#endif /* KVM_CAP_IRQ_ROUTING */
+ case KVM_IRQFD: {
+ struct kvm_irqfd data;
+
+ r = -EFAULT;
+ if (copy_from_user(&data, argp, sizeof data))
+ goto out;
+ r = kvm_irqfd(kvm, data.fd, data.gsi, data.flags);
+ break;
+ }
default:
r = kvm_arch_vm_ioctl(filp, ioctl, arg);
}