kvm: allow arbitrarily sized mmio ioeventfd

We use a 2 byte ioeventfd for virtio memory,
add support for this.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Amos Kong <akong@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/kvm.h b/kvm.h
index 330f17b..9bdbdb0 100644
--- a/kvm.h
+++ b/kvm.h
@@ -210,7 +210,8 @@
 #endif
 
 #endif
-int kvm_set_ioeventfd_mmio_long(int fd, uint32_t adr, uint32_t val, bool assign);
+int kvm_set_ioeventfd_mmio(int fd, uint32_t adr, uint32_t val, bool assign,
+                           uint32_t size);
 
 int kvm_set_ioeventfd_pio_word(int fd, uint16_t adr, uint16_t val, bool assign);
 #endif