Failed to run ubuntu_sysdig_smoke_test on B-KVM kernel

This is a two-folded issue:
  1. DKMS module failed to build
  2. Unable to modprobe sysdig-probe

Steps:
  1. Deploy a KVM instance with Bionic, install linux-kvm on it.
  2. Install sysdig-dkms

Result:
    Setting up sysdig-dkms (0.19.1-1build2) ...
    Loading new sysdig-0.19.1 DKMS files...
    Building for 4.15.0-1004-kvm
    Building initial module for 4.15.0-1004-kvm
    Error! Bad return status for module build on kernel: 4.15.0-1004-kvm (x86_64)

The dkms make log:
    DKMS make.log for sysdig-0.19.1 for kernel 4.15.0-1004-kvm (x86_64)
    Tue Apr 17 09:11:09 UTC 2018
    make: Entering directory '/usr/src/linux-headers-4.15.0-1004-kvm'
    Makefile:974: *** "Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel". Stop.
    make: Leaving directory '/usr/src/linux-headers-4.15.0-1004-kvm'

Install libelf-dev can solve the module build issue. But note that we don't ask the test to install this package, and it runs smoothly on the other releases.

Furthermore, even with the libelf-dev, sysdig-dkms module install, command "sudo modprobe sysdig-probe" will return:

[ 1667.146657] sysdig_probe: Unknown symbol tracepoint_probe_unregister (err 0)
[ 1667.146766] sysdig_probe: Unknown symbol for_each_kernel_tracepoint (err 0)
[ 1667.146774] sysdig_probe: Unknown symbol tracepoint_probe_register (err 0)

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-1004-kvm 4.15.0-1004.4
ProcVersionSignature: User Name 4.15.0-1004.4-kvm 4.15.15
Uname: Linux 4.15.0-1004-kvm x86_64
ApportVersion: 2.20.9-0ubuntu5
Architecture: amd64
Date: Tue Apr 17 09:11:17 2018
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=C.UTF-8
 SHELL=/bin/bash
SourcePackage: linux-kvm
UpgradeStatus: No upgrade log present (probably fresh install)