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    1: Introduction
    2: ============
    3: 
    4: [![[Xen
    5: screenshot]](http://www.netbsd.org/gallery/in-Action/hubertf-xens.png)](../../gallery/in-Action/hubertf-xen.png)
    6: 
    7: Xen is a virtual machine monitor or hypervisor for x86 hardware
    8: (i686-class or higher), which supports running multiple guest
    9: operating systems on a single physical machine.  With Xen, one uses
   10: the Xen kernel to control the CPU, memory and console, a dom0
   11: operating system which mediates access to other hardware (e.g., disks,
   12: network, USB), and one or more domU operating systems which operate in
   13: an unprivileged virtualized environment.  IO requests from the domU
   14: systems are forwarded by the hypervisor (Xen) to the dom0 to be
   15: fulfilled.
   16: 
   17: Xen supports two styles of guests.  The original is Para-Virtualized
   18: (PV) which means that the guest OS does not attempt to access hardware
   19: directly, but instead makes hypercalls to the hypervisor.  This is
   20: analogous to a user-space program making system calls.  (The dom0
   21: operating system uses PV calls for some functions, such as updating
   22: memory mapping page tables, but has direct hardware access for disk
   23: and network.)   PV guests must be specifically coded for Xen.
   24: 
   25: The more recent style is HVM, which means that the guest does not have
   26: code for Xen and need not be aware that it is running under Xen.
   27: Attempts to access hardware registers are trapped and emulated.  This
   28: style is less efficient but can run unmodified guests.
   29: 
   30: At boot, the dom0 kernel is loaded as module with Xen as the kernel.
   31: The dom0 can start one or more domUs.  (Booting is explained in detail
   32: in the dom0 section.)
   33: 
   34: NetBSD supports Xen in that it can serve as dom0, be used as a domU,
   35: and that Xen kernels and tools are available in pkgsrc.  This HOWTO
   36: attempts to address both the case of running a NetBSD dom0 on hardware
   37: and running NetBSD as a domU in a VPS.
   38: 
   39: Prerequisites
   40: -------------
   41: 
   42: Installing NetBSD/Xen is not extremely difficult, but it is more
   43: complex than a normal installation of NetBSD.
   44: In general, this HOWTO is occasionally overly restrictive about how
   45: things must be done, guiding the reader to stay on the established
   46: path when there are no known good reasons to stray.
   47: 
   48: This HOWTO presumes a basic familiarity with the Xen system
   49: architecture.  This HOWTO presumes familiarity with installing NetBSD
   50: on i386/amd64 hardware and installing software from pkgsrc.
   51: 
   52: See also the [Xen website](http://www.xen.org/).
   53: 
   54: Versions of Xen and NetBSD
   55: ==========================
   56: 
   57: Most of the installation concepts and instructions are independent of
   58: Xen version.  This section gives advice on which version to choose.
   59: Versions not in pkgsrc and older unsupported versions of NetBSD are
   60: inentionally ignored.
   61: 
   62: Xen
   63: ---
   64: 
   65: In NetBSD, xen is provided in pkgsrc, via matching pairs of packages
   66: xenkernel and xentools.  We will refer only to the kernel versions,
   67: but note that both packages must be installed together and must have
   68: matching versions.
   69: 
   70: xenkernel3 and xenkernel33 provide Xen 3.1 and 3.3.  These no longer
   71: receive security patches and should not be used.
   72: 
   73: xenkernel41 provides Xen 4.1.  This is no longer maintained by Xen,
   74: but as of 2014-12 receives backported security patches.  It is a
   75: reasonable although trailing-edge choice.
   76: 
   77: xenkernel42 provides Xen 4.2.  This is maintained by Xen, but old as
   78: of 2014-12.
   79: 
   80: Ideally newer versions of Xen will be added to pkgsrc.
   81: 
   82: NetBSD
   83: ------
   84: 
   85: The netbsd-5, netbsd-6, netbsd-7, and -current branches are all
   86: reasonable choices, with more or less the same considerations for
   87: non-Xen use.  Therefore, netbsd-6 is recommended as the stable version
   88: of the most recent release.
   89: 
   90: As of NetBSD 6, a NetBSD domU will support multiple vcpus.  There is
   91: no SMP support for NetBSD as dom0.  (The dom0 itself doesn't really
   92: need SMP; the lack of support is really a problem when using a dom0 as
   93: a normal computer.)
   94: 
   95: Recommendation
   96: --------------
   97: 
   98: Therefore, this HOWTO recommends running xenkernel42 (and xentools42)
   99: and NetBSD 6 stable branch.
  100: 
  101: NetBSD as a dom0
  102: ================
  103: 
  104: NetBSD can be used as a dom0 and works very well.  The following
  105: sections address installation, updating NetBSD, and updating Xen.
  106: 
  107: Styles of dom0 operation
  108: ------------------------
  109: 
  110: There are two basic ways to use Xen.  The traditional method is for
  111: the dom0 to do absolutely nothing other than providing support to some
  112: number of domUs.  Such a system was probably installed for the sole
  113: purpose of hosting domUs, and sits in a server room on a UPS.
  114: 
  115: The other way is to put Xen under a normal-usage computer, so that the
  116: dom0 is what the computer would have been without Xen, perhaps a
  117: desktop or laptop.  Then, one can run domUs at will.  Purists will
  118: deride this as less secure than the previous approach, and for a
  119: computer whose purpose is to run domUs, they are right.  But Xen and a
  120: dom0 (without domUs) is not meaingfully less secure than the same
  121: things running without Xen.  One can boot Xen or boot regular NetBSD
  122: alternately with little problems, simply refraining from starting the
  123: Xen daemons when not running Xen.
  124: 
  125: Note that NetBSD as dom0 does not support multiple CPUs.  This will
  126: limit the performance of the Xen/dom0 workstation approach.
  127: 
  128: Installation of NetBSD and Xen
  129: ------------------------------
  130: 
  131: Note that it doesn't make sense to talk about installing a dom0 OS
  132: without also installing Xen itself.
  133: 
  134: First do a NetBSD/i386 or NetBSD/amd64
  135: [installation](../../docs/guide/en/chap-inst.html) of the 5.1 release
  136: (or newer) as you usually do on x86 hardware. The binary releases are
  137: available from [](ftp://ftp.NetBSD.org/pub/NetBSD/). Binary snapshots
  138: for current and the stable branches are available on daily autobuilds.
  139: If you plan to use the `grub` boot loader, when partitioning the disk
  140: you have to make the root partition smaller than 512Mb, and formatted as
  141: FFSv1 with 8k block/1k fragments. If the partition is larger than this,
  142: uses FFSv2 or has different block/fragment sizes, grub may fail to load
  143: some files. Also keep in mind that you'll probably want to provide
  144: virtual disks to other domains, so reserve some partitions for these
  145: virtual disks. Alternatively, you can create large files in the file
  146: system, map them to vnd(4) devices and export theses vnd devices to
  147: other domains.
  148: 
  149: Next step is to install the Xen packages via pkgsrc or from binary
  150: packages. See [the pkgsrc
  151: documentation](http://www.NetBSD.org/docs/pkgsrc/) if you are unfamiliar
  152: with pkgsrc and/or handling of binary packages. Xen 3.1, 3.3, 4.1 and
  153: 4.2 are available. 3.1 supports PCI pass-through while other versions do
  154: not. You'll need either `sysutils/xentools3` and `sysutils/xenkernel3`
  155: for Xen 3.1, `sysutils/xentools33` and `sysutils/xenkernel33` for Xen
  156: 3.3, `sysutils/xentools41` and `sysutils/xenkernel41` for Xen 4.1. or
  157: `sysutils/xentools42` and `sysutils/xenkernel42` for Xen 4.2. You'll
  158: also need `sysutils/grub` if you plan do use the grub boot loader. If
  159: using Xen 3.1, you may also want to install `sysutils/xentools3-hvm`
  160: which contains the utilities to run unmodified guests OSes using the
  161: *HVM* support (for later versions this is included in
  162: `sysutils/xentools`). Note that your CPU needs to support this. Intel
  163: CPUs must have the 'VT' instruction, AMD CPUs the 'SVM' instruction. You
  164: can easily find out if your CPU support HVM by using NetBSD's cpuctl
  165: command:
  166: 
  167:     # cpuctl identify 0
  168:     cpu0: Intel Core 2 (Merom) (686-class), id 0x6f6
  169:     cpu0: features 0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR>
  170:     cpu0: features 0xbfebfbff<PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX>
  171:     cpu0: features 0xbfebfbff<FXSR,SSE,SSE2,SS,HTT,TM,SBF>
  172:     cpu0: features2 0x4e33d<SSE3,DTES64,MONITOR,DS-CPL,,TM2,SSSE3,CX16,xTPR,PDCM,DCA>
  173:     cpu0: features3 0x20100800<SYSCALL/SYSRET,XD,EM64T>
  174:     cpu0: "Intel(R) Xeon(R) CPU            5130  @ 2.00GHz"
  175:     cpu0: I-cache 32KB 64B/line 8-way, D-cache 32KB 64B/line 8-way
  176:     cpu0: L2 cache 4MB 64B/line 16-way
  177:     cpu0: ITLB 128 4KB entries 4-way
  178:     cpu0: DTLB 256 4KB entries 4-way, 32 4MB entries 4-way
  179:     cpu0: Initial APIC ID 0
  180:     cpu0: Cluster/Package ID 0
  181:     cpu0: Core ID 0
  182:     cpu0: family 06 model 0f extfamily 00 extmodel 00
  183: 
  184: Depending on your CPU, the feature you are looking for is called HVM,
  185: SVM or VMX.
  186: 
  187: Next you need to copy the selected Xen kernel itself. pkgsrc installed
  188: them under `/usr/pkg/xen*-kernel/`. The file you're looking for is
  189: `xen.gz`. Copy it to your root file system. `xen-debug.gz` is a kernel
  190: with more consistency checks and more details printed on the serial
  191: console. It is useful for debugging crashing guests if you use a serial
  192: console. It is not useful with a VGA console.
  193: 
  194: You'll then need a NetBSD/Xen kernel for *domain0* on your root file
  195: system. The XEN3PAE\_DOM0 kernel or XEN3\_DOM0 provided as part of the
  196: i386 or amd64 binaries is suitable for this, but you may want to
  197: customize it. Keep your native kernel around, as it can be useful for
  198: recovery. *Note:* the *domain0* kernel must support KERNFS and `/kern`
  199: must be mounted because *xend* needs access to `/kern/xen/privcmd`.
  200: 
  201: Next you need to get a bootloader to load the `xen.gz` kernel, and the
  202: NetBSD *domain0* kernel as a module. This can be `grub` or NetBSD's boot
  203: loader. Below is a detailled example for grub, see the boot.cfg(5)
  204: manual page for an example using the latter.
  205: 
  206: This is also where you'll specify the memory allocated to *domain0*, the
  207: console to use, etc ...
  208: 
  209: Here is a commented `/grub/menu.lst` file:
  210: 
  211:     #Grub config file for NetBSD/xen. Copy as /grub/menu.lst and run
  212:     # grub-install /dev/rwd0d (assuming your boot device is wd0).
  213:     #
  214:     # The default entry to load will be the first one
  215:     default=0
  216: 
  217:     # boot the default entry after 10s if the user didn't hit keyboard
  218:     timeout=10
  219: 
  220:     # Configure serial port to use as console. Ignore if you'll use VGA only
  221:     serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1
  222: 
  223:     # Let the user select which console to use (serial or VGA), default
  224:     # to serial after 10s
  225:     terminal --timeout=10 serial console
  226: 
  227:     # An entry for NetBSD/xen, using /netbsd as the domain0 kernel, and serial
  228:     # console. Domain0 will have 64MB RAM allocated.
  229:     # Assume NetBSD is installed in the first MBR partition.
  230:     title Xen 3 / NetBSD (hda0, serial)
  231:       root(hd0,0)
  232:       kernel (hd0,a)/xen.gz dom0_mem=65536 com1=115200,8n1
  233:       module (hd0,a)/netbsd bootdev=wd0a ro console=ttyS0
  234: 
  235:     # Same as above, but using VGA console
  236:     # We can use console=tty0 (Linux syntax) or console=pc (NetBSD syntax)
  237:     title Xen 3 / NetBSD (hda0, vga)
  238:       root(hd0,0)
  239:       kernel (hd0,a)/xen.gz dom0_mem=65536
  240:       module (hd0,a)/netbsd bootdev=wd0a ro console=tty0
  241: 
  242:     # NetBSD/xen using a backup domain0 kernel (in case you installed a
  243:     # nonworking kernel as /netbsd
  244:     title Xen 3 / NetBSD (hda0, backup, serial)
  245:       root(hd0,0)
  246:       kernel (hd0,a)/xen.gz dom0_mem=65536 com1=115200,8n1
  247:       module (hd0,a)/netbsd.backup bootdev=wd0a ro console=ttyS0
  248:     title Xen 3 / NetBSD (hda0, backup, VGA)
  249:       root(hd0,0)
  250:       kernel (hd0,a)/xen.gz dom0_mem=65536
  251:       module (hd0,a)/netbsd.backup bootdev=wd0a ro console=tty0
  252: 
  253:     #Load a regular NetBSD/i386 kernel. Can be useful if you end up with a
  254:     #nonworking /xen.gz
  255:     title NetBSD 5.1
  256:       root (hd0,a)
  257:       kernel --type=netbsd /netbsd-GENERIC
  258: 
  259:     #Load the NetBSD bootloader, letting it load the NetBSD/i386 kernel.
  260:     #May be better than the above, as grub can't pass all required infos
  261:     #to the NetBSD/i386 kernel (e.g. console, root device, ...)
  262:     title NetBSD chain
  263:       root        (hd0,0)
  264:       chainloader +1
  265: 
  266:     ## end of grub config file.
  267:           
  268: 
  269: Install grub with the following command:
  270: 
  271:     # grub --no-floppy
  272: 
  273:     grub> root (hd0,a)
  274:      Filesystem type is ffs, partition type 0xa9
  275: 
  276:     grub> setup (hd0)
  277:      Checking if "/boot/grub/stage1" exists... no
  278:      Checking if "/grub/stage1" exists... yes
  279:      Checking if "/grub/stage2" exists... yes
  280:      Checking if "/grub/ffs_stage1_5" exists... yes
  281:      Running "embed /grub/ffs_stage1_5 (hd0)"...  14 sectors are embedded.
  282:     succeeded
  283:      Running "install /grub/stage1 (hd0) (hd0)1+14 p (hd0,0,a)/grub/stage2 /grub/menu.lst"...
  284:      succeeded
  285:     Done.
  286:           
  287: 
  288: Updating NetBSD in a dom0
  289: -------------------------
  290: 
  291: This is just like updating NetBSD on bare hardware, assuming the new
  292: version supports the version of Xen you are running.  Generally, one
  293: replaces the kernel and reboots, and then overlays userland binaries
  294: and adjusts /etc.
  295: 
  296: Note that one must update both the non-Xen kernel typically used for
  297: rescue purposes and the DOM0 kernel used with Xen.
  298: 
  299: Updating Xen versions
  300: ---------------------
  301: 
  302: TODO: write
  303: 
  304: Creating unprivileged domains (domU)
  305: ====================================
  306: 
  307: Creating domUs is almost entirely independent of operating system.  We
  308: first explain NetBSD, and then differences for Linux and Solaris.
  309: 
  310: Creating an unprivileged NetBSD domain (domU)
  311: ---------------------------------------------
  312: 
  313: Once you have *domain0* running, you need to start the xen tool daemon
  314: (`/usr/pkg/share/examples/rc.d/xend start`) and the xen backend daemon
  315: (`/usr/pkg/share/examples/rc.d/xenbackendd start` for Xen3\*,
  316: `/usr/pkg/share/examples/rc.d/xencommons start` for Xen4.\*). Make sure
  317: that `/dev/xencons` and `/dev/xenevt` exist before starting `xend`. You
  318: can create them with this command:
  319: 
  320:     # cd /dev && sh MAKEDEV xen
  321: 
  322: xend will write logs to `/var/log/xend.log` and
  323: `/var/log/xend-debug.log`. You can then control xen with the xm tool.
  324: 'xm list' will show something like:
  325: 
  326:     # xm list
  327:     Name              Id  Mem(MB)  CPU  State  Time(s)  Console
  328:     Domain-0           0       64    0  r----     58.1
  329: 
  330: 'xm create' allows you to create a new domain. It uses a config file in
  331: PKG\_SYSCONFDIR for its parameters. By default, this file will be in
  332: `/usr/pkg/etc/xen/`. On creation, a kernel has to be specified, which
  333: will be executed in the new domain (this kernel is in the *domain0* file
  334: system, not on the new domain virtual disk; but please note, you should
  335: install the same kernel into *domainU* as `/netbsd` in order to make
  336: your system tools, like MAN.SAVECORE.8, work). A suitable kernel is
  337: provided as part of the i386 and amd64 binary sets: XEN3\_DOMU.
  338: 
  339: Here is an /usr/pkg/etc/xen/nbsd example config file:
  340: 
  341:     #  -*- mode: python; -*-
  342:     #============================================================================
  343:     # Python defaults setup for 'xm create'.
  344:     # Edit this file to reflect the configuration of your system.
  345:     #============================================================================
  346: 
  347:     #----------------------------------------------------------------------------
  348:     # Kernel image file. This kernel will be loaded in the new domain.
  349:     kernel = "/home/bouyer/netbsd-XEN3_DOMU"
  350:     #kernel = "/home/bouyer/netbsd-INSTALL_XEN3_DOMU"
  351: 
  352:     # Memory allocation (in megabytes) for the new domain.
  353:     memory = 128
  354: 
  355:     # A handy name for your new domain. This will appear in 'xm list',
  356:     # and you can use this as parameters for xm in place of the domain
  357:     # number. All domains must have different names.
  358:     #
  359:     name = "nbsd"
  360: 
  361:     # The number of virtual CPUs this domain has.
  362:     #
  363:     vcpus = 1
  364: 
  365:     #----------------------------------------------------------------------------
  366:     # Define network interfaces for the new domain.
  367: 
  368:     # Number of network interfaces (must be at least 1). Default is 1.
  369:     nics = 1
  370: 
  371:     # Define MAC and/or bridge for the network interfaces.
  372:     #
  373:     # The MAC address specified in ``mac'' is the one used for the interface
  374:     # in the new domain. The interface in domain0 will use this address XOR'd
  375:     # with 00:00:00:01:00:00 (i.e. aa:00:00:51:02:f0 in our example). Random
  376:     # MACs are assigned if not given.
  377:     #
  378:     # ``bridge'' is a required parameter, which will be passed to the
  379:     # vif-script called by xend(8) when a new domain is created to configure
  380:     # the new xvif interface in domain0.
  381:     #
  382:     # In this example, the xvif is added to bridge0, which should have been
  383:     # set up prior to the new domain being created -- either in the
  384:     # ``network'' script or using a /etc/ifconfig.bridge0 file.
  385:     #
  386:     vif = [ 'mac=aa:00:00:50:02:f0, bridge=bridge0' ]
  387: 
  388:     #----------------------------------------------------------------------------
  389:     # Define the disk devices you want the domain to have access to, and
  390:     # what you want them accessible as.
  391:     #
  392:     # Each disk entry is of the form:
  393:     #
  394:     #   phy:DEV,VDEV,MODE
  395:     #
  396:     # where DEV is the device, VDEV is the device name the domain will see,
  397:     # and MODE is r for read-only, w for read-write.  You can also create
  398:     # file-backed domains using disk entries of the form:
  399:     #
  400:     #   file:PATH,VDEV,MODE
  401:     #
  402:     # where PATH is the path to the file used as the virtual disk, and VDEV
  403:     # and MODE have the same meaning as for ``phy'' devices.
  404:     #
  405:     # VDEV doesn't really matter for a NetBSD guest OS (it's just used as an index),
  406:     # but it does for Linux.
  407:     # Worse, the device has to exist in /dev/ of domain0, because xm will
  408:     # try to stat() it. This means that in order to load a Linux guest OS
  409:     # from a NetBSD domain0, you'll have to create /dev/hda1, /dev/hda2, ...
  410:     # on domain0, with the major/minor from Linux :(
  411:     # Alternatively it's possible to specify the device number in hex,
  412:     # e.g. 0x301 for /dev/hda1, 0x302 for /dev/hda2, etc ...
  413: 
  414:     disk = [ 'phy:/dev/wd0e,0x1,w' ]
  415:     #disk = [ 'file:/var/xen/nbsd-disk,0x01,w' ]
  416:     #disk = [ 'file:/var/xen/nbsd-disk,0x301,w' ]
  417: 
  418:     #----------------------------------------------------------------------------
  419:     # Set the kernel command line for the new domain.
  420: 
  421:     # Set root device. This one does matter for NetBSD
  422:     root = "xbd0"
  423:     # extra parameters passed to the kernel
  424:     # this is where you can set boot flags like -s, -a, etc ...
  425:     #extra = ""
  426: 
  427:     #----------------------------------------------------------------------------
  428:     # Set according to whether you want the domain restarted when it exits.
  429:     # The default is False.
  430:     #autorestart = True
  431: 
  432:     # end of nbsd config file ====================================================
  433: 
  434: When a new domain is created, xen calls the
  435: `/usr/pkg/etc/xen/vif-bridge` script for each virtual network interface
  436: created in *domain0*. This can be used to automatically configure the
  437: xvif?.? interfaces in *domain0*. In our example, these will be bridged
  438: with the bridge0 device in *domain0*, but the bridge has to exist first.
  439: To do this, create the file `/etc/ifconfig.bridge0` and make it look
  440: like this:
  441: 
  442:     create
  443:     !brconfig $int add ex0 up
  444: 
  445: (replace `ex0` with the name of your physical interface). Then bridge0
  446: will be created on boot. See the MAN.BRIDGE.4 man page for details.
  447: 
  448: So, here is a suitable `/usr/pkg/etc/xen/vif-bridge` for xvif?.? (a
  449: working vif-bridge is also provided with xentools20) configuring:
  450: 
  451:     #!/bin/sh
  452:     #============================================================================
  453:     # $NetBSD: howto.mdwn,v 1.16 2014/12/24 00:06:01 gdt Exp $
  454:     #
  455:     # /usr/pkg/etc/xen/vif-bridge
  456:     #
  457:     # Script for configuring a vif in bridged mode with a dom0 interface.
  458:     # The xend(8) daemon calls a vif script when bringing a vif up or down.
  459:     # The script name to use is defined in /usr/pkg/etc/xen/xend-config.sxp
  460:     # in the ``vif-script'' field.
  461:     #
  462:     # Usage: vif-bridge up|down [var=value ...]
  463:     #
  464:     # Actions:
  465:     #    up     Adds the vif interface to the bridge.
  466:     #    down   Removes the vif interface from the bridge.
  467:     #
  468:     # Variables:
  469:     #    domain name of the domain the interface is on (required).
  470:     #    vifq   vif interface name (required).
  471:     #    mac    vif MAC address (required).
  472:     #    bridge bridge to add the vif to (required).
  473:     #
  474:     # Example invocation:
  475:     #
  476:     # vif-bridge up domain=VM1 vif=xvif1.0 mac="ee:14:01:d0:ec:af" bridge=bridge0
  477:     #
  478:     #============================================================================
  479: 
  480:     # Exit if anything goes wrong
  481:     set -e
  482: 
  483:     echo "vif-bridge $*"
  484: 
  485:     # Operation name.
  486:     OP=$1; shift
  487: 
  488:     # Pull variables in args into environment
  489:     for arg ; do export "${arg}" ; done
  490: 
  491:     # Required parameters. Fail if not set.
  492:     domain=${domain:?}
  493:     vif=${vif:?}
  494:     mac=${mac:?}
  495:     bridge=${bridge:?}
  496: 
  497:     # Optional parameters. Set defaults.
  498:     ip=${ip:-''}   # default to null (do nothing)
  499: 
  500:     # Are we going up or down?
  501:     case $OP in
  502:     up) brcmd='add' ;;
  503:     down)   brcmd='delete' ;;
  504:     *)
  505:         echo 'Invalid command: ' $OP
  506:         echo 'Valid commands are: up, down'
  507:         exit 1
  508:         ;;
  509:     esac
  510: 
  511:     # Don't do anything if the bridge is "null".
  512:     if [ "${bridge}" = "null" ] ; then
  513:         exit
  514:     fi
  515: 
  516:     # Don't do anything if the bridge doesn't exist.
  517:     if ! ifconfig -l | grep "${bridge}" >/dev/null; then
  518:         exit
  519:     fi
  520: 
  521:     # Add/remove vif to/from bridge.
  522:     ifconfig x${vif} $OP
  523:     brconfig ${bridge} ${brcmd} x${vif}
  524: 
  525: Now, running
  526: 
  527:     xm create -c /usr/pkg/etc/xen/nbsd
  528: 
  529: should create a domain and load a NetBSD kernel in it. (Note: `-c`
  530: causes xm to connect to the domain's console once created.) The kernel
  531: will try to find its root file system on xbd0 (i.e., wd0e) which hasn't
  532: been created yet. wd0e will be seen as a disk device in the new domain,
  533: so it will be 'sub-partitioned'. We could attach a ccd to wd0e in
  534: *domain0* and partition it, newfs and extract the NetBSD/i386 or amd64
  535: tarballs there, but there's an easier way: load the
  536: `netbsd-INSTALL_XEN3_DOMU` kernel provided in the NetBSD binary sets.
  537: Like other install kernels, it contains a ramdisk with sysinst, so you
  538: can install NetBSD using sysinst on your new domain.
  539: 
  540: If you want to install NetBSD/Xen with a CDROM image, the following line
  541: should be used in the `/usr/pkg/etc/xen/nbsd` file:
  542: 
  543:     disk = [ 'phy:/dev/wd0e,0x1,w', 'phy:/dev/cd0a,0x2,r' ]
  544: 
  545: After booting the domain, the option to install via CDROM may be
  546: selected. The CDROM device should be changed to `xbd1d`.
  547: 
  548: Once done installing, `halt -p` the new domain (don't reboot or halt, it
  549: would reload the INSTALL\_XEN3\_DOMU kernel even if you changed the
  550: config file), switch the config file back to the XEN3\_DOMU kernel, and
  551: start the new domain again. Now it should be able to use `root on xbd0a`
  552: and you should have a second, functional NetBSD system on your xen
  553: installation.
  554: 
  555: When the new domain is booting you'll see some warnings about *wscons*
  556: and the pseudo-terminals. These can be fixed by editing the files
  557: `/etc/ttys` and `/etc/wscons.conf`. You must disable all terminals in
  558: `/etc/ttys`, except *console*, like this:
  559: 
  560:     console "/usr/libexec/getty Pc"         vt100   on secure
  561:     ttyE0   "/usr/libexec/getty Pc"         vt220   off secure
  562:     ttyE1   "/usr/libexec/getty Pc"         vt220   off secure
  563:     ttyE2   "/usr/libexec/getty Pc"         vt220   off secure
  564:     ttyE3   "/usr/libexec/getty Pc"         vt220   off secure
  565: 
  566: Finally, all screens must be commented out from `/etc/wscons.conf`.
  567: 
  568: It is also desirable to add
  569: 
  570:     powerd=YES
  571: 
  572: in rc.conf. This way, the domain will be properly shut down if
  573: `xm shutdown -R` or `xm shutdown -H` is used on the domain0.
  574: 
  575: Your domain should be now ready to work, enjoy.
  576: 
  577: Creating an unprivileged Linux domain (domU)
  578: --------------------------------------------
  579: 
  580: Creating unprivileged Linux domains isn't much different from
  581: unprivileged NetBSD domains, but there are some details to know.
  582: 
  583: First, the second parameter passed to the disk declaration (the '0x1' in
  584: the example below)
  585: 
  586:     disk = [ 'phy:/dev/wd0e,0x1,w' ]
  587: 
  588: does matter to Linux. It wants a Linux device number here (e.g. 0x300
  589: for hda). Linux builds device numbers as: (major \<\< 8 + minor). So,
  590: hda1 which has major 3 and minor 1 on a Linux system will have device
  591: number 0x301. Alternatively, devices names can be used (hda, hdb, ...)
  592: as xentools has a table to map these names to devices numbers. To export
  593: a partition to a Linux guest we can use:
  594: 
  595:     disk = [ 'phy:/dev/wd0e,0x300,w' ]
  596:     root = "/dev/hda1 ro"
  597: 
  598: and it will appear as /dev/hda on the Linux system, and be used as root
  599: partition.
  600: 
  601: To install the Linux system on the partition to be exported to the guest
  602: domain, the following method can be used: install sysutils/e2fsprogs
  603: from pkgsrc. Use mke2fs to format the partition that will be the root
  604: partition of your Linux domain, and mount it. Then copy the files from a
  605: working Linux system, make adjustments in `/etc` (fstab, network
  606: config). It should also be possible to extract binary packages such as
  607: .rpm or .deb directly to the mounted partition using the appropriate
  608: tool, possibly running under NetBSD's Linux emulation. Once the
  609: filesystem has been populated, umount it. If desirable, the filesystem
  610: can be converted to ext3 using tune2fs -j. It should now be possible to
  611: boot the Linux guest domain, using one of the vmlinuz-\*-xenU kernels
  612: available in the Xen binary distribution.
  613: 
  614: To get the linux console right, you need to add:
  615: 
  616:     extra = "xencons=tty1"
  617: 
  618: to your configuration since not all linux distributions auto-attach a
  619: tty to the xen console.
  620: 
  621: Creating an unprivileged Solaris domain (domU)
  622: ----------------------------------------------
  623: 
  624: Download an Opensolaris [release](http://opensolaris.org/os/downloads/)
  625: or [development snapshot](http://genunix.org/) DVD image. Attach the DVD
  626: image to a MAN.VND.4 device. Copy the kernel and ramdisk filesystem
  627: image to your dom0 filesystem.
  628: 
  629:     dom0# mkdir /root/solaris
  630:     dom0# vnconfig vnd0 osol-1002-124-x86.iso
  631:     dom0# mount /dev/vnd0a /mnt
  632: 
  633:     ## for a 64-bit guest
  634:     dom0# cp /mnt/boot/amd64/x86.microroot /root/solaris
  635:     dom0# cp /mnt/platform/i86xpv/kernel/amd64/unix /root/solaris
  636: 
  637:     ## for a 32-bit guest
  638:     dom0# cp /mnt/boot/x86.microroot /root/solaris
  639:     dom0# cp /mnt/platform/i86xpv/kernel/unix /root/solaris
  640: 
  641:     dom0# umount /mnt
  642:           
  643: 
  644: Keep the MAN.VND.4 configured. For some reason the boot process stalls
  645: unless the DVD image is attached to the guest as a "phy" device. Create
  646: an initial configuration file with the following contents. Substitute
  647: */dev/wd0k* with an empty partition at least 8 GB large.
  648: 
  649:     memory = 640
  650:     name = 'solaris'
  651:     disk = [ 'phy:/dev/wd0k,0,w' ]
  652:     disk += [ 'phy:/dev/vnd0d,6:cdrom,r' ]
  653:     vif = [ 'bridge=bridge0' ]
  654:     kernel = '/root/solaris/unix'
  655:     ramdisk = '/root/solaris/x86.microroot'
  656:     # for a 64-bit guest
  657:     extra = '/platform/i86xpv/kernel/amd64/unix - nowin -B install_media=cdrom'
  658:     # for a 32-bit guest
  659:     #extra = '/platform/i86xpv/kernel/unix - nowin -B install_media=cdrom'
  660:           
  661: 
  662: Start the guest.
  663: 
  664:     dom0# xm create -c solaris.cfg
  665:     Started domain solaris
  666:                           v3.3.2 chgset 'unavailable'
  667:     SunOS Release 5.11 Version snv_124 64-bit
  668:     Copyright 1983-2009 Sun Microsystems, Inc.  All rights reserved.
  669:     Use is subject to license terms.
  670:     Hostname: opensolaris
  671:     Remounting root read/write
  672:     Probing for device nodes ...
  673:     WARNING: emlxs: ddi_modopen drv/fct failed: err 2
  674:     Preparing live image for use
  675:     Done mounting Live image
  676:           
  677: 
  678: Make sure the network is configured. Note that it can take a minute for
  679: the xnf0 interface to appear.
  680: 
  681:     opensolaris console login: jack
  682:     Password: jack
  683:     Sun Microsystems Inc.   SunOS 5.11      snv_124 November 2008
  684:     jack@opensolaris:~$ pfexec sh
  685:     sh-3.2# ifconfig -a
  686:     sh-3.2# exit
  687:           
  688: 
  689: Set a password for VNC and start the VNC server which provides the X11
  690: display where the installation program runs.
  691: 
  692:     jack@opensolaris:~$ vncpasswd
  693:     Password: solaris
  694:     Verify: solaris
  695:     jack@opensolaris:~$ cp .Xclients .vnc/xstartup
  696:     jack@opensolaris:~$ vncserver :1
  697:           
  698: 
  699: From a remote machine connect to the VNC server. Use `ifconfig xnf0` on
  700: the guest to find the correct IP address to use.
  701: 
  702:     remote$ vncviewer 172.18.2.99:1
  703:           
  704: 
  705: It is also possible to launch the installation on a remote X11 display.
  706: 
  707:     jack@opensolaris:~$ export DISPLAY=172.18.1.1:0
  708:     jack@opensolaris:~$ pfexec gui-install
  709:            
  710: 
  711: After the GUI installation is complete you will be asked to reboot.
  712: Before that you need to determine the ZFS ID for the new boot filesystem
  713: and update the configuration file accordingly. Return to the guest
  714: console.
  715: 
  716:     jack@opensolaris:~$ pfexec zdb -vvv rpool | grep bootfs
  717:                     bootfs = 43
  718:     ^C
  719:     jack@opensolaris:~$
  720:            
  721: 
  722: The final configuration file should look like this. Note in particular
  723: the last line.
  724: 
  725:     memory = 640
  726:     name = 'solaris'
  727:     disk = [ 'phy:/dev/wd0k,0,w' ]
  728:     vif = [ 'bridge=bridge0' ]
  729:     kernel = '/root/solaris/unix'
  730:     ramdisk = '/root/solaris/x86.microroot'
  731:     extra = '/platform/i86xpv/kernel/amd64/unix -B zfs-bootfs=rpool/43,bootpath="/xpvd/xdf@0:a"'
  732:            
  733: 
  734: Restart the guest to verify it works correctly.
  735: 
  736:     dom0# xm destroy solaris
  737:     dom0# xm create -c solaris.cfg
  738:     Using config file "./solaris.cfg".
  739:     v3.3.2 chgset 'unavailable'
  740:     Started domain solaris
  741:     SunOS Release 5.11 Version snv_124 64-bit
  742:     Copyright 1983-2009 Sun Microsystems, Inc.  All rights reserved.
  743:     Use is subject to license terms.
  744:     WARNING: emlxs: ddi_modopen drv/fct failed: err 2
  745:     Hostname: osol
  746:     Configuring devices.
  747:     Loading smf(5) service descriptions: 160/160
  748:     svccfg import warnings. See /var/svc/log/system-manifest-import:default.log .
  749:     Reading ZFS config: done.
  750:     Mounting ZFS filesystems: (6/6)
  751:     Creating new rsa public/private host key pair
  752:     Creating new dsa public/private host key pair
  753: 
  754:     osol console login:
  755:            
  756: 
  757: Using PCI devices in guest domains
  758: ----------------------------------
  759: 
  760: The domain0 can give other domains access to selected PCI devices. This
  761: can allow, for example, a non-privileged domain to have access to a
  762: physical network interface or disk controller. However, keep in mind
  763: that giving a domain access to a PCI device most likely will give the
  764: domain read/write access to the whole physical memory, as PCs don't have
  765: an IOMMU to restrict memory access to DMA-capable device. Also, it's not
  766: possible to export ISA devices to non-domain0 domains (which means that
  767: the primary VGA adapter can't be exported. A guest domain trying to
  768: access the VGA registers will panic).
  769: 
  770: This functionality is only available in NetBSD-5.1 (and later) domain0
  771: and domU. If the domain0 is NetBSD, it has to be running Xen 3.1, as
  772: support has not been ported to later versions at this time.
  773: 
  774: For a PCI device to be exported to a domU, is has to be attached to the
  775: `pciback` driver in domain0. Devices passed to the domain0 via the
  776: pciback.hide boot parameter will attach to `pciback` instead of the
  777: usual driver. The list of devices is specified as `(bus:dev.func)`,
  778: where bus and dev are 2-digit hexadecimal numbers, and func a
  779: single-digit number:
  780: 
  781:     pciback.hide=(00:0a.0)(00:06.0)
  782: 
  783: pciback devices should show up in the domain0's boot messages, and the
  784: devices should be listed in the `/kern/xen/pci` directory.
  785: 
  786: PCI devices to be exported to a domU are listed in the `pci` array of
  787: the domU's config file, with the format `'0000:bus:dev.func'`
  788: 
  789:     pci = [ '0000:00:06.0', '0000:00:0a.0' ]
  790: 
  791: In the domU an `xpci` device will show up, to which one or more pci
  792: busses will attach. Then the PCI drivers will attach to PCI busses as
  793: usual. Note that the default NetBSD DOMU kernels do not have `xpci` or
  794: any PCI drivers built in by default; you have to build your own kernel
  795: to use PCI devices in a domU. Here's a kernel config example:
  796: 
  797:     include         "arch/i386/conf/XEN3_DOMU"
  798:     #include         "arch/i386/conf/XENU"           # in NetBSD 3.0
  799: 
  800:     # Add support for PCI busses to the XEN3_DOMU kernel
  801:     xpci* at xenbus ?
  802:     pci* at xpci ?
  803: 
  804:     # Now add PCI and related devices to be used by this domain
  805:     # USB Controller and Devices
  806: 
  807:     # PCI USB controllers
  808:     uhci*   at pci? dev ? function ?        # Universal Host Controller (Intel)
  809: 
  810:     # USB bus support
  811:     usb*    at uhci?
  812: 
  813:     # USB Hubs
  814:     uhub*   at usb?
  815:     uhub*   at uhub? port ? configuration ? interface ?
  816: 
  817:     # USB Mass Storage
  818:     umass*  at uhub? port ? configuration ? interface ?
  819:     wd*     at umass?
  820:     # SCSI controllers
  821:     ahc*    at pci? dev ? function ?        # Adaptec [23]94x, aic78x0 SCSI
  822: 
  823:     # SCSI bus support (for both ahc and umass)
  824:     scsibus* at scsi?
  825: 
  826:     # SCSI devices
  827:     sd*     at scsibus? target ? lun ?      # SCSI disk drives
  828:     cd*     at scsibus? target ? lun ?      # SCSI CD-ROM drives
  829: 
  830: Links and further information
  831: =============================
  832: 
  833: -   The [HowTo on Installing into RAID-1](http://mail-index.NetBSD.org/port-xen/2006/03/01/0010.html)
  834:     explains how to set up booting a dom0 with Xen using grub 
  835:     with NetBSD's RAIDframe.  (This is obsolete with the use of
  836:     NetBSD's native boot.)
  837: -   An example of how to use NetBSD's native bootloader to load
  838:     NetBSD/Xen instead of Grub can be found in the i386/amd64 boot(8)
  839:     and boot.cfg(5) manpages.

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