Add API to assign/deassign irqfd to kvm.
Add stub so that users do not have to use
ifdefs.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 kvm-all.c |   19 +++++++++++++++++++
 kvm.h     |   10 ++++++++++
 2 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/kvm-all.c b/kvm-all.c
index efdf40c..b3fdf29 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1122,4 +1122,23 @@ int kvm_set_ioeventfd(uint16_t addr, uint16_t data, int fd, bool assigned)
 }
 #endif
 
+#if defined(KVM_IRQFD)
+int kvm_set_irqfd(int gsi, int fd, bool assigned)
+{
+    struct kvm_irqfd irqfd = {
+        .fd = fd,
+        .gsi = gsi,
+        .flags = assigned ? 0 : KVM_IRQFD_FLAG_DEASSIGN,
+    };
+    int r;
+    if (!kvm_irqchip_in_kernel())
+        return -ENOSYS;
+
+    r = kvm_vm_ioctl(kvm_state, KVM_IRQFD, &irqfd);
+    if (r < 0)
+        return r;
+    return 0;
+}
+#endif
+
 #include "qemu-kvm.c"
diff --git a/kvm.h b/kvm.h
index e98b5c8..ad8d122 100644
--- a/kvm.h
+++ b/kvm.h
@@ -167,4 +167,14 @@ int kvm_set_ioeventfd(uint16_t data, uint16_t addr, int fd, bool assigned)
 }
 #endif
 
+#if defined(KVM_IRQFD) && defined(CONFIG_KVM)
+int kvm_set_irqfd(int gsi, int fd, bool assigned);
+#else
+static inline
+int kvm_set_irqfd(int gsi, int fd, bool assigned)
+{
+    return -ENOSYS;
+}
+#endif
+
 #endif
-- 
1.6.6.144.g5c3af