wiki:Xen_Lab7

Version 14 (modified by rider, 15 years ago) (diff)

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  1. 【前言】
  2. 【Step 0: 流程】
  3. 【Step 1: 首先查看主機上的顯卡資訊】
  4. 【Step 2: 產生一台實驗用虛擬機器】
  5. 【Step 3: PCI Frontend Configuration 設定你的 DomU 】
  6. 【Step 4: PCI Backend Configuration 設定你的 Dom0 】
  7. 【Step 5: 硬體定址存取設定】
        1. Permissive Flag
        2. User-space Quirks
  8. 【Step 6: 啟動並登入你的虛擬機器 DomU 】
  9. 【Step 7: 設定你的 DomU 基本環境】

實作七：Xen PCI Passthrough 操作

【前言】

  • 小叮嚀
    • 為了使 Xen patched Kerenl 能支援 PCI Passthrough, 請務必確認以下Xen 相關的核心配置. 
      CONFIG_XEN_PCIDEV_FRONTEND=y
CONFIG_XEN_PCIDEV_BACKEND=y
CONFIG_XEN_PCIDEV_BACKEND_PASS is not set
CONFIG_XEN_PCIDEV_BACKEND_VPCI=y
CONFIG_XEN_PCIDEV_BACKEND_SLOT is not set
  • 小技巧
    • Binding at Boot-Time.
    • 直接將顯示卡所佔的 PCI_Address 在開機時就隱藏起來,使得一開始便能直接 bind 到該 PCI_Address.
    • 透過 lspci 指令來查詢顯示卡所佔的實體 PCI Address. 
      /boot/vmlinuz-2.6.22.9 root=UUID=d3fa560e-7071-46d8-a168-036f40960c7b ro console=tty0 pciback.hide=(0000:01:00.0)
    • 如果透過 lspci 指令查出顯示卡為 unknown 或是其他不明資訊, 請先更新 PCI ID database 試看看. 
      $ update-pciids

【Step 0: 流程】

  • 本範例將說明如何使用及設定 Xen PCI Passthrough GraphViz image

【Step 1: 首先查看主機上的顯卡資訊】

$ lspci -vv | more

01:00.0 VGA compatible controller: nVidia Corporation G92 [GeForce 9800 GT] (rev a2)
        Subsystem: ASUSTeK Computer Inc. Device 82a0
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0
        Interrupt: pin A routed to IRQ 16
        Region 0: Memory at fd000000 (32-bit, non-prefetchable) [size=16M]
        Region 1: Memory at d0000000 (64-bit, prefetchable) [size=256M]
        Region 3: Memory at fa000000 (64-bit, non-prefetchable) [size=32M]
        Region 5: I/O ports at dc80 [size=128]
        [virtual] Expansion ROM at fea00000 [disabled] [size=128K]
        Capabilities: <access denied>
        Kernel driver in use: nvidia
        Kernel modules: nvidia, nvidiafb

【Step 2: 產生一台實驗用虛擬機器】

  • 設定你想要怎樣規格的虛擬機器. 
    $ sudo vim /etc/xen-tools/xen-tools.conf

    dir = /home
install-method = debootstrap
size   = 4Gb      # Disk image size.
memory = 256Mb    # Memory size
swap   = 128Mb    # Swap size
fs     = ext3     # use the EXT3 filesystem for the disk image.
dist   = hardy    # Default distribution to install. ---> For CUDA Support (Ubuntu 8.0.4)
image  = sparse   # Specify sparse vs. full disk images.
gateway   = 192.168.100.254
netmask   = 255.255.255.0
broadcast = 192.168.100.255
kernel      = /boot/vmlinuz-`uname -r`
initrd      = /boot/initrd.img-`uname -r`
mirror = http://gb.archive.ubuntu.com/ubuntu/
ext3_options   = noatime,nodiratime,errors=remount-ro
ext2_options   = noatime,nodiratime,errors=remount-ro
xfs_options    = defaults
reiser_options = defaults

    $ sudo xen-create-image --hostname=xg01 --ip=192.168.100.X --mac=00:16:XX:XX:XX:XX --force

【Step 3: PCI Frontend Configuration 設定你的 DomU 】

$ sudo vim /etc/xen/xg01.cfg

kernel      = '/boot/vmlinuz-2.6.22.9'
ramdisk     = '/boot/initrd.img-2.6.22.9'
 
memory      = '256'
vcpus       = '4'

# 配置你的 PCIE 顯示卡
pci         = ['01:00.0']

root        = '/dev/sda2 ro'
disk        = [
                  'file:/home/domains/xg01/disk.img,sda2,w',
                  'file:/home/domains/xg01/swap.img,sda1,w',
              ]
name        = 'xg01'
 
#
#  Networking
#
vif         = [ 'ip=192.168.100.X ,mac=00:16:XX:XX:XX:XX' ]
 
#
#  Behaviour
#
on_poweroff = 'destroy'
on_reboot   = 'restart'
on_crash    = 'restart'

【Step 4: PCI Backend Configuration 設定你的 Dom0 】

  • 切換身份為 Super user. 
    $ sudo su -
  • 隱藏 dom0 的PCI 匯流排的位址, 並交由 pciback 模組來控制該匯流排存取權. 
    $ echo -n "0000:01:00.0" > /sys/bus/pci/drivers/nvidia/unbind
  • 將 dev_ids 轉到 pciback 成為新的 binding slot. 
    $ echo -n "0000:01:00.0" > /sys/bus/pci/drivers/pciback/new_slot
$ echo -n "0000:01:00.0" > /sys/bus/pci/drivers/pciback/bind

    $ cat /sys/bus/pci/drivers/pciback/slots

    0000:01:00.0
  • 警告: 請確認您的顯示卡資源沒有被其 Kernel module 所佔有及控制: 您顯示卡的 symlink 不應該存在著. 
    PATH: /sys/bus/pci/devices/0000:01:00.0/
driver -> ../../../../bus/pci/drivers/nvidia ---> 此連結不應存在. NVIDIA module 已無該裝置控制權.
driver -> ../../../../bus/pci/drivers/pciback ---> 控制權應該已經交賦予 pciback module.

【Step 5: 硬體定址存取設定】

Permissive Flag

$ sudo vim /etc/xen/xend-pci-permissive.sxp

(unconstrained_dev_ids
     #('0123:4567:89AB:CDEF')
     ('0000:01:00.0')
)

User-space Quirks

$ sudo vim /etc/xen/xend-pci-quirks.sxp

(pci_ids
   # Entries are formated as follows:  
   #     <vendor>:<device>[:<subvendor>:<subdevice>]

   ('10de:0605'   # NVIDIA 9800GT
   )
)

【Step 6: 啟動並登入你的虛擬機器 DomU 】

  • 說明: 先用 root 免密碼登入.
  • @ Dom0 
    $ sudo xm create -c xg01.cfg

【Step 7: 設定你的 DomU 基本環境】

  • 設定 locales (系統語系),避免亂碼現象發生.(如無此問題可以略過語系設定) 
    $ sudo vim /etc/profile

    # Locale
export LANGUAGE="en_US.UTF-8"
export LC_ALL="en_US.UTF-8"
export LANG="en_US.UTF-8"

    $ source /etc/profile
$ sudo dpkg-reconfigure locales
  • 更新 PCI ID Database.(當您發現系統無法偵測到你的顯示卡時) 
    $ sudo apt-get update
$ sudo apt-get install wget
$ sudo update-pciids
  • 查看顯卡資訊有無正常顯示. 
    $ lspci

    00:00.0 VGA compatible controller: nVidia Corporation G92 [GeForce 9800 GT] (rev a2)
  • 查看顯卡資源有無順利分配到 DomU. 
    $ dmesg | grep pci

    pcifront pci-0: Installing PCI frontend
pcifront pci-0: Creating PCI Frontend Bus 0000:00
pciback 0000:00:00.0: probing...
pciback: pcistub_init_devices_late

【討論 & 休息】