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>

1 files changed, 4 insertions, 0 deletions

diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index 79e83fc00dc7..56c6848d2df8 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -5,3 +5,7 @@ config HAVE_KVM
 
 config HAVE_KVM_IRQCHIP
        bool
+
+config HAVE_KVM_EVENTFD
+       bool
+       select EVENTFD