GCC Version:
  gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-44)

CC       builtin-balloon.o
In file included from include/kvm/pci.h:7:0,
                 from include/kvm/vfio.h:6,
                 from include/kvm/kvm-config.h:5,
                 from include/kvm/kvm.h:6,
                 from builtin-balloon.c:9:
include/linux/virtio_pci.h:326:2: error: implicit declaration of function ‘__KERNEL_DIV_ROUND_UP’ [-Werror=implicit-function-declaration]
  __le64 supported_caps[MAX_CAP_ID];
  ^
include/linux/virtio_pci.h:326:9: error: variably modified ‘supported_caps’ at file scope
  __le64 supported_caps[MAX_CAP_ID];
         ^
cc1: all warnings being treated as errors
make: *** [builtin-balloon.o] Error 1

Signed-off-by: hbuxiaofei <hbuxiaofei@gmail.com>
---
 include/linux/virtio_pci.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/virtio_pci.h b/include/linux/virtio_pci.h
index e732e34..fb2f66a 100644
--- a/include/linux/virtio_pci.h
+++ b/include/linux/virtio_pci.h
@@ -39,6 +39,7 @@
 #ifndef _LINUX_VIRTIO_PCI_H
 #define _LINUX_VIRTIO_PCI_H
 
+#include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/const.h>
 
-- 
2.43.7