reproduce:
        # https://github.com/sean-jc/linux/commit/d7309d0e5d4d02c0fbb83488623bcfbe71f0be38
        git remote add sean-jc https://github.com/sean-jc/linux
        git fetch --no-tags sean-jc rev/map_gmem
        git checkout d7309d0e5d4d02c0fbb83488623bcfbe71f0be38
        # choose either of the following two methods to reproduce the issue
        # 1. reproduce by kismet
           # install kmax per https://github.com/paulgazz/kmax/blob/master/README.md
           kismet --linux-ksrc=linux --selectees CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES --selectors CONFIG_KVM_SW_PROTECTED_VM -a=x86_64
        # 2. reproduce by make
           cd linux
           # download the config file from the "config:" link in the report, and save it as .config
           make ARCH=x86_64 olddefconfig