File:  [NetBSD Developer Wiki] / wikisrc / ports / xen / howto.mdwn
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Wed Dec 24 00:11:15 2014 UTC (4 years, 11 months ago) by gdt
Branches: MAIN
CVS tags: HEAD
address amd64 vs i386

    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: See also the [Xen website](http://www.xen.org/).
   52: 
   53: Versions of Xen and NetBSD
   54: ==========================
   55: 
   56: Most of the installation concepts and instructions are independent of
   57: Xen version.  This section gives advice on which version to choose.
   58: Versions not in pkgsrc and older unsupported versions of NetBSD are
   59: inentionally ignored.
   60: 
   61: Xen
   62: ---
   63: 
   64: In NetBSD, xen is provided in pkgsrc, via matching pairs of packages
   65: xenkernel and xentools.  We will refer only to the kernel versions,
   66: but note that both packages must be installed together and must have
   67: matching versions.
   68: 
   69: xenkernel3 and xenkernel33 provide Xen 3.1 and 3.3.  These no longer
   70: receive security patches and should not be used.
   71: 
   72: xenkernel41 provides Xen 4.1.  This is no longer maintained by Xen,
   73: but as of 2014-12 receives backported security patches.  It is a
   74: reasonable although trailing-edge choice.
   75: 
   76: xenkernel42 provides Xen 4.2.  This is maintained by Xen, but old as
   77: of 2014-12.
   78: 
   79: Ideally newer versions of Xen will be added to pkgsrc.
   80: 
   81: NetBSD
   82: ------
   83: 
   84: The netbsd-5, netbsd-6, netbsd-7, and -current branches are all
   85: reasonable choices, with more or less the same considerations for
   86: non-Xen use.  Therefore, netbsd-6 is recommended as the stable version
   87: of the most recent release.
   88: 
   89: As of NetBSD 6, a NetBSD domU will support multiple vcpus.  There is
   90: no SMP support for NetBSD as dom0.  (The dom0 itself doesn't really
   91: need SMP; the lack of support is really a problem when using a dom0 as
   92: a normal computer.)
   93: 
   94: Architecture
   95: ------------
   96: 
   97: Xen is basically amd64 only at this point.  One can either run i386
   98: domains or amd64 domains.  If running i386, PAE versions are required,
   99: for both dom0 and domU.  These versions are built by default in NetBSD
  100: releases.  While i386 dom0 works fine, amd64 is recommended as more
  101: normal.  (Note that emacs (at least) fails if run on i386 with PAE when
  102: built without, and vice versa, presumably due to bugs in the undump
  103: code.)
  104: 
  105: Recommendation
  106: --------------
  107: 
  108: Therefore, this HOWTO recommends running xenkernel42 (and xentools42),
  109: the NetBSD 6 stable branch, and to use amd64 as the dom0.  Either the
  110: i386 or amd64 of NetBSD may be used as domUs.
  111: 
  112: NetBSD as a dom0
  113: ================
  114: 
  115: NetBSD can be used as a dom0 and works very well.  The following
  116: sections address installation, updating NetBSD, and updating Xen.
  117: 
  118: Styles of dom0 operation
  119: ------------------------
  120: 
  121: There are two basic ways to use Xen.  The traditional method is for
  122: the dom0 to do absolutely nothing other than providing support to some
  123: number of domUs.  Such a system was probably installed for the sole
  124: purpose of hosting domUs, and sits in a server room on a UPS.
  125: 
  126: The other way is to put Xen under a normal-usage computer, so that the
  127: dom0 is what the computer would have been without Xen, perhaps a
  128: desktop or laptop.  Then, one can run domUs at will.  Purists will
  129: deride this as less secure than the previous approach, and for a
  130: computer whose purpose is to run domUs, they are right.  But Xen and a
  131: dom0 (without domUs) is not meaingfully less secure than the same
  132: things running without Xen.  One can boot Xen or boot regular NetBSD
  133: alternately with little problems, simply refraining from starting the
  134: Xen daemons when not running Xen.
  135: 
  136: Note that NetBSD as dom0 does not support multiple CPUs.  This will
  137: limit the performance of the Xen/dom0 workstation approach.
  138: 
  139: Installation of NetBSD and Xen
  140: ------------------------------
  141: 
  142: Note that it doesn't make sense to talk about installing a dom0 OS
  143: without also installing Xen itself.
  144: 
  145: First do a NetBSD/i386 or NetBSD/amd64
  146: [installation](../../docs/guide/en/chap-inst.html) of the 5.1 release
  147: (or newer) as you usually do on x86 hardware. The binary releases are
  148: available from [](ftp://ftp.NetBSD.org/pub/NetBSD/). Binary snapshots
  149: for current and the stable branches are available on daily autobuilds.
  150: If you plan to use the `grub` boot loader, when partitioning the disk
  151: you have to make the root partition smaller than 512Mb, and formatted as
  152: FFSv1 with 8k block/1k fragments. If the partition is larger than this,
  153: uses FFSv2 or has different block/fragment sizes, grub may fail to load
  154: some files. Also keep in mind that you'll probably want to provide
  155: virtual disks to other domains, so reserve some partitions for these
  156: virtual disks. Alternatively, you can create large files in the file
  157: system, map them to vnd(4) devices and export theses vnd devices to
  158: other domains.
  159: 
  160: Next step is to install the Xen packages via pkgsrc or from binary
  161: packages. See [the pkgsrc
  162: documentation](http://www.NetBSD.org/docs/pkgsrc/) if you are unfamiliar
  163: with pkgsrc and/or handling of binary packages. Xen 3.1, 3.3, 4.1 and
  164: 4.2 are available. 3.1 supports PCI pass-through while other versions do
  165: not. You'll need either `sysutils/xentools3` and `sysutils/xenkernel3`
  166: for Xen 3.1, `sysutils/xentools33` and `sysutils/xenkernel33` for Xen
  167: 3.3, `sysutils/xentools41` and `sysutils/xenkernel41` for Xen 4.1. or
  168: `sysutils/xentools42` and `sysutils/xenkernel42` for Xen 4.2. You'll
  169: also need `sysutils/grub` if you plan do use the grub boot loader. If
  170: using Xen 3.1, you may also want to install `sysutils/xentools3-hvm`
  171: which contains the utilities to run unmodified guests OSes using the
  172: *HVM* support (for later versions this is included in
  173: `sysutils/xentools`). Note that your CPU needs to support this. Intel
  174: CPUs must have the 'VT' instruction, AMD CPUs the 'SVM' instruction. You
  175: can easily find out if your CPU support HVM by using NetBSD's cpuctl
  176: command:
  177: 
  178:     # cpuctl identify 0
  179:     cpu0: Intel Core 2 (Merom) (686-class), id 0x6f6
  180:     cpu0: features 0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR>
  181:     cpu0: features 0xbfebfbff<PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX>
  182:     cpu0: features 0xbfebfbff<FXSR,SSE,SSE2,SS,HTT,TM,SBF>
  183:     cpu0: features2 0x4e33d<SSE3,DTES64,MONITOR,DS-CPL,,TM2,SSSE3,CX16,xTPR,PDCM,DCA>
  184:     cpu0: features3 0x20100800<SYSCALL/SYSRET,XD,EM64T>
  185:     cpu0: "Intel(R) Xeon(R) CPU            5130  @ 2.00GHz"
  186:     cpu0: I-cache 32KB 64B/line 8-way, D-cache 32KB 64B/line 8-way
  187:     cpu0: L2 cache 4MB 64B/line 16-way
  188:     cpu0: ITLB 128 4KB entries 4-way
  189:     cpu0: DTLB 256 4KB entries 4-way, 32 4MB entries 4-way
  190:     cpu0: Initial APIC ID 0
  191:     cpu0: Cluster/Package ID 0
  192:     cpu0: Core ID 0
  193:     cpu0: family 06 model 0f extfamily 00 extmodel 00
  194: 
  195: Depending on your CPU, the feature you are looking for is called HVM,
  196: SVM or VMX.
  197: 
  198: Next you need to copy the selected Xen kernel itself. pkgsrc installed
  199: them under `/usr/pkg/xen*-kernel/`. The file you're looking for is
  200: `xen.gz`. Copy it to your root file system. `xen-debug.gz` is a kernel
  201: with more consistency checks and more details printed on the serial
  202: console. It is useful for debugging crashing guests if you use a serial
  203: console. It is not useful with a VGA console.
  204: 
  205: You'll then need a NetBSD/Xen kernel for *domain0* on your root file
  206: system. The XEN3PAE\_DOM0 kernel or XEN3\_DOM0 provided as part of the
  207: i386 or amd64 binaries is suitable for this, but you may want to
  208: customize it. Keep your native kernel around, as it can be useful for
  209: recovery. *Note:* the *domain0* kernel must support KERNFS and `/kern`
  210: must be mounted because *xend* needs access to `/kern/xen/privcmd`.
  211: 
  212: Next you need to get a bootloader to load the `xen.gz` kernel, and the
  213: NetBSD *domain0* kernel as a module. This can be `grub` or NetBSD's boot
  214: loader. Below is a detailled example for grub, see the boot.cfg(5)
  215: manual page for an example using the latter.
  216: 
  217: This is also where you'll specify the memory allocated to *domain0*, the
  218: console to use, etc ...
  219: 
  220: Here is a commented `/grub/menu.lst` file:
  221: 
  222:     #Grub config file for NetBSD/xen. Copy as /grub/menu.lst and run
  223:     # grub-install /dev/rwd0d (assuming your boot device is wd0).
  224:     #
  225:     # The default entry to load will be the first one
  226:     default=0
  227: 
  228:     # boot the default entry after 10s if the user didn't hit keyboard
  229:     timeout=10
  230: 
  231:     # Configure serial port to use as console. Ignore if you'll use VGA only
  232:     serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1
  233: 
  234:     # Let the user select which console to use (serial or VGA), default
  235:     # to serial after 10s
  236:     terminal --timeout=10 serial console
  237: 
  238:     # An entry for NetBSD/xen, using /netbsd as the domain0 kernel, and serial
  239:     # console. Domain0 will have 64MB RAM allocated.
  240:     # Assume NetBSD is installed in the first MBR partition.
  241:     title Xen 3 / NetBSD (hda0, serial)
  242:       root(hd0,0)
  243:       kernel (hd0,a)/xen.gz dom0_mem=65536 com1=115200,8n1
  244:       module (hd0,a)/netbsd bootdev=wd0a ro console=ttyS0
  245: 
  246:     # Same as above, but using VGA console
  247:     # We can use console=tty0 (Linux syntax) or console=pc (NetBSD syntax)
  248:     title Xen 3 / NetBSD (hda0, vga)
  249:       root(hd0,0)
  250:       kernel (hd0,a)/xen.gz dom0_mem=65536
  251:       module (hd0,a)/netbsd bootdev=wd0a ro console=tty0
  252: 
  253:     # NetBSD/xen using a backup domain0 kernel (in case you installed a
  254:     # nonworking kernel as /netbsd
  255:     title Xen 3 / NetBSD (hda0, backup, serial)
  256:       root(hd0,0)
  257:       kernel (hd0,a)/xen.gz dom0_mem=65536 com1=115200,8n1
  258:       module (hd0,a)/netbsd.backup bootdev=wd0a ro console=ttyS0
  259:     title Xen 3 / NetBSD (hda0, backup, VGA)
  260:       root(hd0,0)
  261:       kernel (hd0,a)/xen.gz dom0_mem=65536
  262:       module (hd0,a)/netbsd.backup bootdev=wd0a ro console=tty0
  263: 
  264:     #Load a regular NetBSD/i386 kernel. Can be useful if you end up with a
  265:     #nonworking /xen.gz
  266:     title NetBSD 5.1
  267:       root (hd0,a)
  268:       kernel --type=netbsd /netbsd-GENERIC
  269: 
  270:     #Load the NetBSD bootloader, letting it load the NetBSD/i386 kernel.
  271:     #May be better than the above, as grub can't pass all required infos
  272:     #to the NetBSD/i386 kernel (e.g. console, root device, ...)
  273:     title NetBSD chain
  274:       root        (hd0,0)
  275:       chainloader +1
  276: 
  277:     ## end of grub config file.
  278:           
  279: 
  280: Install grub with the following command:
  281: 
  282:     # grub --no-floppy
  283: 
  284:     grub> root (hd0,a)
  285:      Filesystem type is ffs, partition type 0xa9
  286: 
  287:     grub> setup (hd0)
  288:      Checking if "/boot/grub/stage1" exists... no
  289:      Checking if "/grub/stage1" exists... yes
  290:      Checking if "/grub/stage2" exists... yes
  291:      Checking if "/grub/ffs_stage1_5" exists... yes
  292:      Running "embed /grub/ffs_stage1_5 (hd0)"...  14 sectors are embedded.
  293:     succeeded
  294:      Running "install /grub/stage1 (hd0) (hd0)1+14 p (hd0,0,a)/grub/stage2 /grub/menu.lst"...
  295:      succeeded
  296:     Done.
  297:           
  298: 
  299: Updating NetBSD in a dom0
  300: -------------------------
  301: 
  302: This is just like updating NetBSD on bare hardware, assuming the new
  303: version supports the version of Xen you are running.  Generally, one
  304: replaces the kernel and reboots, and then overlays userland binaries
  305: and adjusts /etc.
  306: 
  307: Note that one must update both the non-Xen kernel typically used for
  308: rescue purposes and the DOM0 kernel used with Xen.
  309: 
  310: Updating Xen versions
  311: ---------------------
  312: 
  313: TODO: write
  314: 
  315: Creating unprivileged domains (domU)
  316: ====================================
  317: 
  318: Creating domUs is almost entirely independent of operating system.  We
  319: first explain NetBSD, and then differences for Linux and Solaris.
  320: 
  321: Creating an unprivileged NetBSD domain (domU)
  322: ---------------------------------------------
  323: 
  324: Once you have *domain0* running, you need to start the xen tool daemon
  325: (`/usr/pkg/share/examples/rc.d/xend start`) and the xen backend daemon
  326: (`/usr/pkg/share/examples/rc.d/xenbackendd start` for Xen3\*,
  327: `/usr/pkg/share/examples/rc.d/xencommons start` for Xen4.\*). Make sure
  328: that `/dev/xencons` and `/dev/xenevt` exist before starting `xend`. You
  329: can create them with this command:
  330: 
  331:     # cd /dev && sh MAKEDEV xen
  332: 
  333: xend will write logs to `/var/log/xend.log` and
  334: `/var/log/xend-debug.log`. You can then control xen with the xm tool.
  335: 'xm list' will show something like:
  336: 
  337:     # xm list
  338:     Name              Id  Mem(MB)  CPU  State  Time(s)  Console
  339:     Domain-0           0       64    0  r----     58.1
  340: 
  341: 'xm create' allows you to create a new domain. It uses a config file in
  342: PKG\_SYSCONFDIR for its parameters. By default, this file will be in
  343: `/usr/pkg/etc/xen/`. On creation, a kernel has to be specified, which
  344: will be executed in the new domain (this kernel is in the *domain0* file
  345: system, not on the new domain virtual disk; but please note, you should
  346: install the same kernel into *domainU* as `/netbsd` in order to make
  347: your system tools, like MAN.SAVECORE.8, work). A suitable kernel is
  348: provided as part of the i386 and amd64 binary sets: XEN3\_DOMU.
  349: 
  350: Here is an /usr/pkg/etc/xen/nbsd example config file:
  351: 
  352:     #  -*- mode: python; -*-
  353:     #============================================================================
  354:     # Python defaults setup for 'xm create'.
  355:     # Edit this file to reflect the configuration of your system.
  356:     #============================================================================
  357: 
  358:     #----------------------------------------------------------------------------
  359:     # Kernel image file. This kernel will be loaded in the new domain.
  360:     kernel = "/home/bouyer/netbsd-XEN3_DOMU"
  361:     #kernel = "/home/bouyer/netbsd-INSTALL_XEN3_DOMU"
  362: 
  363:     # Memory allocation (in megabytes) for the new domain.
  364:     memory = 128
  365: 
  366:     # A handy name for your new domain. This will appear in 'xm list',
  367:     # and you can use this as parameters for xm in place of the domain
  368:     # number. All domains must have different names.
  369:     #
  370:     name = "nbsd"
  371: 
  372:     # The number of virtual CPUs this domain has.
  373:     #
  374:     vcpus = 1
  375: 
  376:     #----------------------------------------------------------------------------
  377:     # Define network interfaces for the new domain.
  378: 
  379:     # Number of network interfaces (must be at least 1). Default is 1.
  380:     nics = 1
  381: 
  382:     # Define MAC and/or bridge for the network interfaces.
  383:     #
  384:     # The MAC address specified in ``mac'' is the one used for the interface
  385:     # in the new domain. The interface in domain0 will use this address XOR'd
  386:     # with 00:00:00:01:00:00 (i.e. aa:00:00:51:02:f0 in our example). Random
  387:     # MACs are assigned if not given.
  388:     #
  389:     # ``bridge'' is a required parameter, which will be passed to the
  390:     # vif-script called by xend(8) when a new domain is created to configure
  391:     # the new xvif interface in domain0.
  392:     #
  393:     # In this example, the xvif is added to bridge0, which should have been
  394:     # set up prior to the new domain being created -- either in the
  395:     # ``network'' script or using a /etc/ifconfig.bridge0 file.
  396:     #
  397:     vif = [ 'mac=aa:00:00:50:02:f0, bridge=bridge0' ]
  398: 
  399:     #----------------------------------------------------------------------------
  400:     # Define the disk devices you want the domain to have access to, and
  401:     # what you want them accessible as.
  402:     #
  403:     # Each disk entry is of the form:
  404:     #
  405:     #   phy:DEV,VDEV,MODE
  406:     #
  407:     # where DEV is the device, VDEV is the device name the domain will see,
  408:     # and MODE is r for read-only, w for read-write.  You can also create
  409:     # file-backed domains using disk entries of the form:
  410:     #
  411:     #   file:PATH,VDEV,MODE
  412:     #
  413:     # where PATH is the path to the file used as the virtual disk, and VDEV
  414:     # and MODE have the same meaning as for ``phy'' devices.
  415:     #
  416:     # VDEV doesn't really matter for a NetBSD guest OS (it's just used as an index),
  417:     # but it does for Linux.
  418:     # Worse, the device has to exist in /dev/ of domain0, because xm will
  419:     # try to stat() it. This means that in order to load a Linux guest OS
  420:     # from a NetBSD domain0, you'll have to create /dev/hda1, /dev/hda2, ...
  421:     # on domain0, with the major/minor from Linux :(
  422:     # Alternatively it's possible to specify the device number in hex,
  423:     # e.g. 0x301 for /dev/hda1, 0x302 for /dev/hda2, etc ...
  424: 
  425:     disk = [ 'phy:/dev/wd0e,0x1,w' ]
  426:     #disk = [ 'file:/var/xen/nbsd-disk,0x01,w' ]
  427:     #disk = [ 'file:/var/xen/nbsd-disk,0x301,w' ]
  428: 
  429:     #----------------------------------------------------------------------------
  430:     # Set the kernel command line for the new domain.
  431: 
  432:     # Set root device. This one does matter for NetBSD
  433:     root = "xbd0"
  434:     # extra parameters passed to the kernel
  435:     # this is where you can set boot flags like -s, -a, etc ...
  436:     #extra = ""
  437: 
  438:     #----------------------------------------------------------------------------
  439:     # Set according to whether you want the domain restarted when it exits.
  440:     # The default is False.
  441:     #autorestart = True
  442: 
  443:     # end of nbsd config file ====================================================
  444: 
  445: When a new domain is created, xen calls the
  446: `/usr/pkg/etc/xen/vif-bridge` script for each virtual network interface
  447: created in *domain0*. This can be used to automatically configure the
  448: xvif?.? interfaces in *domain0*. In our example, these will be bridged
  449: with the bridge0 device in *domain0*, but the bridge has to exist first.
  450: To do this, create the file `/etc/ifconfig.bridge0` and make it look
  451: like this:
  452: 
  453:     create
  454:     !brconfig $int add ex0 up
  455: 
  456: (replace `ex0` with the name of your physical interface). Then bridge0
  457: will be created on boot. See the MAN.BRIDGE.4 man page for details.
  458: 
  459: So, here is a suitable `/usr/pkg/etc/xen/vif-bridge` for xvif?.? (a
  460: working vif-bridge is also provided with xentools20) configuring:
  461: 
  462:     #!/bin/sh
  463:     #============================================================================
  464:     # $NetBSD: howto.mdwn,v 1.18 2014/12/24 00:11:15 gdt Exp $
  465:     #
  466:     # /usr/pkg/etc/xen/vif-bridge
  467:     #
  468:     # Script for configuring a vif in bridged mode with a dom0 interface.
  469:     # The xend(8) daemon calls a vif script when bringing a vif up or down.
  470:     # The script name to use is defined in /usr/pkg/etc/xen/xend-config.sxp
  471:     # in the ``vif-script'' field.
  472:     #
  473:     # Usage: vif-bridge up|down [var=value ...]
  474:     #
  475:     # Actions:
  476:     #    up     Adds the vif interface to the bridge.
  477:     #    down   Removes the vif interface from the bridge.
  478:     #
  479:     # Variables:
  480:     #    domain name of the domain the interface is on (required).
  481:     #    vifq   vif interface name (required).
  482:     #    mac    vif MAC address (required).
  483:     #    bridge bridge to add the vif to (required).
  484:     #
  485:     # Example invocation:
  486:     #
  487:     # vif-bridge up domain=VM1 vif=xvif1.0 mac="ee:14:01:d0:ec:af" bridge=bridge0
  488:     #
  489:     #============================================================================
  490: 
  491:     # Exit if anything goes wrong
  492:     set -e
  493: 
  494:     echo "vif-bridge $*"
  495: 
  496:     # Operation name.
  497:     OP=$1; shift
  498: 
  499:     # Pull variables in args into environment
  500:     for arg ; do export "${arg}" ; done
  501: 
  502:     # Required parameters. Fail if not set.
  503:     domain=${domain:?}
  504:     vif=${vif:?}
  505:     mac=${mac:?}
  506:     bridge=${bridge:?}
  507: 
  508:     # Optional parameters. Set defaults.
  509:     ip=${ip:-''}   # default to null (do nothing)
  510: 
  511:     # Are we going up or down?
  512:     case $OP in
  513:     up) brcmd='add' ;;
  514:     down)   brcmd='delete' ;;
  515:     *)
  516:         echo 'Invalid command: ' $OP
  517:         echo 'Valid commands are: up, down'
  518:         exit 1
  519:         ;;
  520:     esac
  521: 
  522:     # Don't do anything if the bridge is "null".
  523:     if [ "${bridge}" = "null" ] ; then
  524:         exit
  525:     fi
  526: 
  527:     # Don't do anything if the bridge doesn't exist.
  528:     if ! ifconfig -l | grep "${bridge}" >/dev/null; then
  529:         exit
  530:     fi
  531: 
  532:     # Add/remove vif to/from bridge.
  533:     ifconfig x${vif} $OP
  534:     brconfig ${bridge} ${brcmd} x${vif}
  535: 
  536: Now, running
  537: 
  538:     xm create -c /usr/pkg/etc/xen/nbsd
  539: 
  540: should create a domain and load a NetBSD kernel in it. (Note: `-c`
  541: causes xm to connect to the domain's console once created.) The kernel
  542: will try to find its root file system on xbd0 (i.e., wd0e) which hasn't
  543: been created yet. wd0e will be seen as a disk device in the new domain,
  544: so it will be 'sub-partitioned'. We could attach a ccd to wd0e in
  545: *domain0* and partition it, newfs and extract the NetBSD/i386 or amd64
  546: tarballs there, but there's an easier way: load the
  547: `netbsd-INSTALL_XEN3_DOMU` kernel provided in the NetBSD binary sets.
  548: Like other install kernels, it contains a ramdisk with sysinst, so you
  549: can install NetBSD using sysinst on your new domain.
  550: 
  551: If you want to install NetBSD/Xen with a CDROM image, the following line
  552: should be used in the `/usr/pkg/etc/xen/nbsd` file:
  553: 
  554:     disk = [ 'phy:/dev/wd0e,0x1,w', 'phy:/dev/cd0a,0x2,r' ]
  555: 
  556: After booting the domain, the option to install via CDROM may be
  557: selected. The CDROM device should be changed to `xbd1d`.
  558: 
  559: Once done installing, `halt -p` the new domain (don't reboot or halt, it
  560: would reload the INSTALL\_XEN3\_DOMU kernel even if you changed the
  561: config file), switch the config file back to the XEN3\_DOMU kernel, and
  562: start the new domain again. Now it should be able to use `root on xbd0a`
  563: and you should have a second, functional NetBSD system on your xen
  564: installation.
  565: 
  566: When the new domain is booting you'll see some warnings about *wscons*
  567: and the pseudo-terminals. These can be fixed by editing the files
  568: `/etc/ttys` and `/etc/wscons.conf`. You must disable all terminals in
  569: `/etc/ttys`, except *console*, like this:
  570: 
  571:     console "/usr/libexec/getty Pc"         vt100   on secure
  572:     ttyE0   "/usr/libexec/getty Pc"         vt220   off secure
  573:     ttyE1   "/usr/libexec/getty Pc"         vt220   off secure
  574:     ttyE2   "/usr/libexec/getty Pc"         vt220   off secure
  575:     ttyE3   "/usr/libexec/getty Pc"         vt220   off secure
  576: 
  577: Finally, all screens must be commented out from `/etc/wscons.conf`.
  578: 
  579: It is also desirable to add
  580: 
  581:     powerd=YES
  582: 
  583: in rc.conf. This way, the domain will be properly shut down if
  584: `xm shutdown -R` or `xm shutdown -H` is used on the domain0.
  585: 
  586: Your domain should be now ready to work, enjoy.
  587: 
  588: Creating an unprivileged Linux domain (domU)
  589: --------------------------------------------
  590: 
  591: Creating unprivileged Linux domains isn't much different from
  592: unprivileged NetBSD domains, but there are some details to know.
  593: 
  594: First, the second parameter passed to the disk declaration (the '0x1' in
  595: the example below)
  596: 
  597:     disk = [ 'phy:/dev/wd0e,0x1,w' ]
  598: 
  599: does matter to Linux. It wants a Linux device number here (e.g. 0x300
  600: for hda). Linux builds device numbers as: (major \<\< 8 + minor). So,
  601: hda1 which has major 3 and minor 1 on a Linux system will have device
  602: number 0x301. Alternatively, devices names can be used (hda, hdb, ...)
  603: as xentools has a table to map these names to devices numbers. To export
  604: a partition to a Linux guest we can use:
  605: 
  606:     disk = [ 'phy:/dev/wd0e,0x300,w' ]
  607:     root = "/dev/hda1 ro"
  608: 
  609: and it will appear as /dev/hda on the Linux system, and be used as root
  610: partition.
  611: 
  612: To install the Linux system on the partition to be exported to the guest
  613: domain, the following method can be used: install sysutils/e2fsprogs
  614: from pkgsrc. Use mke2fs to format the partition that will be the root
  615: partition of your Linux domain, and mount it. Then copy the files from a
  616: working Linux system, make adjustments in `/etc` (fstab, network
  617: config). It should also be possible to extract binary packages such as
  618: .rpm or .deb directly to the mounted partition using the appropriate
  619: tool, possibly running under NetBSD's Linux emulation. Once the
  620: filesystem has been populated, umount it. If desirable, the filesystem
  621: can be converted to ext3 using tune2fs -j. It should now be possible to
  622: boot the Linux guest domain, using one of the vmlinuz-\*-xenU kernels
  623: available in the Xen binary distribution.
  624: 
  625: To get the linux console right, you need to add:
  626: 
  627:     extra = "xencons=tty1"
  628: 
  629: to your configuration since not all linux distributions auto-attach a
  630: tty to the xen console.
  631: 
  632: Creating an unprivileged Solaris domain (domU)
  633: ----------------------------------------------
  634: 
  635: Download an Opensolaris [release](http://opensolaris.org/os/downloads/)
  636: or [development snapshot](http://genunix.org/) DVD image. Attach the DVD
  637: image to a MAN.VND.4 device. Copy the kernel and ramdisk filesystem
  638: image to your dom0 filesystem.
  639: 
  640:     dom0# mkdir /root/solaris
  641:     dom0# vnconfig vnd0 osol-1002-124-x86.iso
  642:     dom0# mount /dev/vnd0a /mnt
  643: 
  644:     ## for a 64-bit guest
  645:     dom0# cp /mnt/boot/amd64/x86.microroot /root/solaris
  646:     dom0# cp /mnt/platform/i86xpv/kernel/amd64/unix /root/solaris
  647: 
  648:     ## for a 32-bit guest
  649:     dom0# cp /mnt/boot/x86.microroot /root/solaris
  650:     dom0# cp /mnt/platform/i86xpv/kernel/unix /root/solaris
  651: 
  652:     dom0# umount /mnt
  653:           
  654: 
  655: Keep the MAN.VND.4 configured. For some reason the boot process stalls
  656: unless the DVD image is attached to the guest as a "phy" device. Create
  657: an initial configuration file with the following contents. Substitute
  658: */dev/wd0k* with an empty partition at least 8 GB large.
  659: 
  660:     memory = 640
  661:     name = 'solaris'
  662:     disk = [ 'phy:/dev/wd0k,0,w' ]
  663:     disk += [ 'phy:/dev/vnd0d,6:cdrom,r' ]
  664:     vif = [ 'bridge=bridge0' ]
  665:     kernel = '/root/solaris/unix'
  666:     ramdisk = '/root/solaris/x86.microroot'
  667:     # for a 64-bit guest
  668:     extra = '/platform/i86xpv/kernel/amd64/unix - nowin -B install_media=cdrom'
  669:     # for a 32-bit guest
  670:     #extra = '/platform/i86xpv/kernel/unix - nowin -B install_media=cdrom'
  671:           
  672: 
  673: Start the guest.
  674: 
  675:     dom0# xm create -c solaris.cfg
  676:     Started domain solaris
  677:                           v3.3.2 chgset 'unavailable'
  678:     SunOS Release 5.11 Version snv_124 64-bit
  679:     Copyright 1983-2009 Sun Microsystems, Inc.  All rights reserved.
  680:     Use is subject to license terms.
  681:     Hostname: opensolaris
  682:     Remounting root read/write
  683:     Probing for device nodes ...
  684:     WARNING: emlxs: ddi_modopen drv/fct failed: err 2
  685:     Preparing live image for use
  686:     Done mounting Live image
  687:           
  688: 
  689: Make sure the network is configured. Note that it can take a minute for
  690: the xnf0 interface to appear.
  691: 
  692:     opensolaris console login: jack
  693:     Password: jack
  694:     Sun Microsystems Inc.   SunOS 5.11      snv_124 November 2008
  695:     jack@opensolaris:~$ pfexec sh
  696:     sh-3.2# ifconfig -a
  697:     sh-3.2# exit
  698:           
  699: 
  700: Set a password for VNC and start the VNC server which provides the X11
  701: display where the installation program runs.
  702: 
  703:     jack@opensolaris:~$ vncpasswd
  704:     Password: solaris
  705:     Verify: solaris
  706:     jack@opensolaris:~$ cp .Xclients .vnc/xstartup
  707:     jack@opensolaris:~$ vncserver :1
  708:           
  709: 
  710: From a remote machine connect to the VNC server. Use `ifconfig xnf0` on
  711: the guest to find the correct IP address to use.
  712: 
  713:     remote$ vncviewer 172.18.2.99:1
  714:           
  715: 
  716: It is also possible to launch the installation on a remote X11 display.
  717: 
  718:     jack@opensolaris:~$ export DISPLAY=172.18.1.1:0
  719:     jack@opensolaris:~$ pfexec gui-install
  720:            
  721: 
  722: After the GUI installation is complete you will be asked to reboot.
  723: Before that you need to determine the ZFS ID for the new boot filesystem
  724: and update the configuration file accordingly. Return to the guest
  725: console.
  726: 
  727:     jack@opensolaris:~$ pfexec zdb -vvv rpool | grep bootfs
  728:                     bootfs = 43
  729:     ^C
  730:     jack@opensolaris:~$
  731:            
  732: 
  733: The final configuration file should look like this. Note in particular
  734: the last line.
  735: 
  736:     memory = 640
  737:     name = 'solaris'
  738:     disk = [ 'phy:/dev/wd0k,0,w' ]
  739:     vif = [ 'bridge=bridge0' ]
  740:     kernel = '/root/solaris/unix'
  741:     ramdisk = '/root/solaris/x86.microroot'
  742:     extra = '/platform/i86xpv/kernel/amd64/unix -B zfs-bootfs=rpool/43,bootpath="/xpvd/xdf@0:a"'
  743:            
  744: 
  745: Restart the guest to verify it works correctly.
  746: 
  747:     dom0# xm destroy solaris
  748:     dom0# xm create -c solaris.cfg
  749:     Using config file "./solaris.cfg".
  750:     v3.3.2 chgset 'unavailable'
  751:     Started domain solaris
  752:     SunOS Release 5.11 Version snv_124 64-bit
  753:     Copyright 1983-2009 Sun Microsystems, Inc.  All rights reserved.
  754:     Use is subject to license terms.
  755:     WARNING: emlxs: ddi_modopen drv/fct failed: err 2
  756:     Hostname: osol
  757:     Configuring devices.
  758:     Loading smf(5) service descriptions: 160/160
  759:     svccfg import warnings. See /var/svc/log/system-manifest-import:default.log .
  760:     Reading ZFS config: done.
  761:     Mounting ZFS filesystems: (6/6)
  762:     Creating new rsa public/private host key pair
  763:     Creating new dsa public/private host key pair
  764: 
  765:     osol console login:
  766:            
  767: 
  768: Using PCI devices in guest domains
  769: ----------------------------------
  770: 
  771: The domain0 can give other domains access to selected PCI devices. This
  772: can allow, for example, a non-privileged domain to have access to a
  773: physical network interface or disk controller. However, keep in mind
  774: that giving a domain access to a PCI device most likely will give the
  775: domain read/write access to the whole physical memory, as PCs don't have
  776: an IOMMU to restrict memory access to DMA-capable device. Also, it's not
  777: possible to export ISA devices to non-domain0 domains (which means that
  778: the primary VGA adapter can't be exported. A guest domain trying to
  779: access the VGA registers will panic).
  780: 
  781: This functionality is only available in NetBSD-5.1 (and later) domain0
  782: and domU. If the domain0 is NetBSD, it has to be running Xen 3.1, as
  783: support has not been ported to later versions at this time.
  784: 
  785: For a PCI device to be exported to a domU, is has to be attached to the
  786: `pciback` driver in domain0. Devices passed to the domain0 via the
  787: pciback.hide boot parameter will attach to `pciback` instead of the
  788: usual driver. The list of devices is specified as `(bus:dev.func)`,
  789: where bus and dev are 2-digit hexadecimal numbers, and func a
  790: single-digit number:
  791: 
  792:     pciback.hide=(00:0a.0)(00:06.0)
  793: 
  794: pciback devices should show up in the domain0's boot messages, and the
  795: devices should be listed in the `/kern/xen/pci` directory.
  796: 
  797: PCI devices to be exported to a domU are listed in the `pci` array of
  798: the domU's config file, with the format `'0000:bus:dev.func'`
  799: 
  800:     pci = [ '0000:00:06.0', '0000:00:0a.0' ]
  801: 
  802: In the domU an `xpci` device will show up, to which one or more pci
  803: busses will attach. Then the PCI drivers will attach to PCI busses as
  804: usual. Note that the default NetBSD DOMU kernels do not have `xpci` or
  805: any PCI drivers built in by default; you have to build your own kernel
  806: to use PCI devices in a domU. Here's a kernel config example:
  807: 
  808:     include         "arch/i386/conf/XEN3_DOMU"
  809:     #include         "arch/i386/conf/XENU"           # in NetBSD 3.0
  810: 
  811:     # Add support for PCI busses to the XEN3_DOMU kernel
  812:     xpci* at xenbus ?
  813:     pci* at xpci ?
  814: 
  815:     # Now add PCI and related devices to be used by this domain
  816:     # USB Controller and Devices
  817: 
  818:     # PCI USB controllers
  819:     uhci*   at pci? dev ? function ?        # Universal Host Controller (Intel)
  820: 
  821:     # USB bus support
  822:     usb*    at uhci?
  823: 
  824:     # USB Hubs
  825:     uhub*   at usb?
  826:     uhub*   at uhub? port ? configuration ? interface ?
  827: 
  828:     # USB Mass Storage
  829:     umass*  at uhub? port ? configuration ? interface ?
  830:     wd*     at umass?
  831:     # SCSI controllers
  832:     ahc*    at pci? dev ? function ?        # Adaptec [23]94x, aic78x0 SCSI
  833: 
  834:     # SCSI bus support (for both ahc and umass)
  835:     scsibus* at scsi?
  836: 
  837:     # SCSI devices
  838:     sd*     at scsibus? target ? lun ?      # SCSI disk drives
  839:     cd*     at scsibus? target ? lun ?      # SCSI CD-ROM drives
  840: 
  841: Links and further information
  842: =============================
  843: 
  844: -   The [HowTo on Installing into RAID-1](http://mail-index.NetBSD.org/port-xen/2006/03/01/0010.html)
  845:     explains how to set up booting a dom0 with Xen using grub 
  846:     with NetBSD's RAIDframe.  (This is obsolete with the use of
  847:     NetBSD's native boot.)
  848: -   An example of how to use NetBSD's native bootloader to load
  849:     NetBSD/Xen instead of Grub can be found in the i386/amd64 boot(8)
  850:     and boot.cfg(5) manpages.

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