3.3 NetBSD VM を作ってみよう

1. まずsysutils/grub2-bhyveを入れる

   # cd /var/ports/bhykx/sysutils/grub2-bhyve
   # make install
   

2. テンプレート(netbsd7.conf)の作成

   # sed -Ee 's/^(network0_switch=).*$/\1"local"/' \
       /vm/.templates/netbsd.conf > /vm/.templates/netbsd7.conf
   # cat /vm/.templates/netbsd7.conf
   loader="grub"
   cpu=1
   memory=256M
   network0_type="virtio-net"
   network0_switch="local"
   disk0_type="virtio-blk"
   disk0_name="disk0.img"
   grub_install0="knetbsd -h -r cd0a /netbsd"
   grub_run0="knetbsd -h -r ld0a /netbsd"
   root@vm:~ # 
   

3. ISOイメージをダウンロード

   # vm iso \
       ftp://ftp.netbsd.org/pub/NetBSD/images/7.0.2/NetBSD-7.0.2-amd64.iso \
   #
   

4. ゲスト(netbsd)の作成

   # vm create -t netbsd7 netbsd
   # ll /vm/netbsd/
   total 1
   -rw-r--r--  1 root  wheel  34359738368 Dec  6 07:33 disk0.img
   -r--r--r--  1 root  wheel          178 Dec  6 07:33 tbedfc.conf
   # cat /vm/netbsd/netbsd.conf 
   loader="grub"
   cpu=1
   memory=256M
   network0_type="virtio-net"
   network0_switch="local"
   disk0_type="virtio-blk"
   disk0_name="disk0.img"
   grub_install0="knetbsd -h -r cd0a /netbsd"
   grub_run0="knetbsd -h -r ld0a /netbsd"
   uuid="d3a5e6af-bc18-11e6-8698-003048dcbe58"
   # mkdir /boot/grub
   # cp \
       /var/ports/usr/ports/sysutils/grub2-bhyve/work/grub2-bhyve-0.40/grub-core/tests/boot/* \
       /boot/grub/
   # vm install netbsd NetBSD-7.0.2-amd64.iso
   Starting netbsd
   * found guest in /vm/netbsd
   ! no unrestricted guest support in cpu. only single vcpu FreeBSD \
       guests supported
   root@vm:~ # 
   % egrep -RnH 'no unrestricted guest support in cpu' \
       /usr/local/lib/vm-bhyve/
   /usr/local/lib/vm-bhyve/vm-core:427: echo " ! no unrestricted \
       guest support in cpu. only single vcpu FreeBSD guests \
       supported"
   /usr/local/lib/vm-bhyve/vm-core.org:425: echo " ! no unrestricted \
       guest support in cpu. only single vcpu FreeBSD guests \
       supported"
   %
   

   • 問題の個所を見ると...

     if [ -n "${VM_NO_UG}" -a "${_loader}" != "bhyveload" ]; then
     echo " ! no unrestricted guest support in cpu. only single vcpu FreeBSD \
         guests supported"
         return 1
     fi
     

   • VM_NO_UGって何だ？

     % egrep -RnH 'VM_NO_UG=' /usr/local/lib/vm-bhyve/
     /usr/local/lib/vm-bhyve/vm-util:89: [ -z "${_result}" ] && \
         VM_NO_UG="1"
     /usr/local/lib/vm-bhyve/vm-core:423: echo \
         "VM_NO_UG=\"${VM_NO_UG}\""
     %
     

   • vm-utilを見るとutil::check_bhyve_supportで定義されていた

         # check ept for intel
         _mesg=$(grep -E '^[ ]+VT-x' /var/run/dmesg.boot | tail -n 1)
     
         if [ -n "${_mesg}" ]; then
     
             # look for ept
             _result=$(echo "${_mesg}" |grep "EPT")
     [ -z "${_result}" ] && util::err "it doesn't look like your cpu supports \
         bhyve (missing EPT)"
     
             # look for unrestricted guest
             _result=$(echo "${_mesg}" |grep ",UG")
             [ -z "${_result}" ] && VM_NO_UG="1"
         fi
     

   • これはdmesg.bootのVT-x行にUGが無いということ
     • Handbookに出てた
       • "21.7. FreeBSD as a Host with bhyve"

       The bhyve design requires a processor that supports Intel Extended Page \
           Tables (
       EPT) or AMD Rapid Virtualization Indexing (RVI) or Nested Page Tables \
           (NPT).
       Hosting Linux guests or FreeBSD guests with more than one vCPU requires VMX
       unrestricted mode support (UG). Most newer processors, specifically the \
           Intel
       Core i3/i5/i7 and Intel Xeon E3/E5/E7, support these features. UG support \
           was
       introduced with Intel's Westmere micro-architecture. For a complete list of \
           Intel
       processors that support EPT, refer to \
           http://ark.intel.com/search/advanced?s=t&
       ExtendedPageTables=true. RVI is found on the third generation and later of \
           the
       AMD Opteron (Barcelona) processors. The easiest way to tell if a processor
       supports bhyve is to run dmesg or look in /var/run/dmesg.boot for the \
           POPCNT
       processor feature flag on the Features2 line for AMD processors or EPT and \
           UG on
       the VT-x line for Intel processors.
       

   • ということで

     • UG(VMX unrestricted mode support)が付いてないCPUでは

       • 2 CPU以上のVMは走らない
       • FreeBSD以外のVMは走らない

       でした;-(

   • BHyVeをやる前には必ず

     % egrep '^ *VT-x:.*,UG' /var/run/dmesg.boot
     

     で確かめましょう．