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 NetBSD/xen Howto  Introduction
 ================  ============
 [![BSD  [![[Xen
 daemon](../../images/BSD-daemon.jpg)](../../about/disclaimer.html#bsd-daemon)  screenshot]](http://www.netbsd.org/gallery/in-Action/hubertf-xens.png)](http://www.netbsd.org/gallery/in-Action/hubertf-xen.png)
 Table Of Contents  Xen is a hypervisor (or virtual machine monitor) for x86 hardware
 -----------------  (i686-class or higher), which supports running multiple guest
   operating systems on a single physical machine.  Xen is a Type 1 or
   bare-metal hypervisor; one uses the Xen kernel to control the CPU,
   memory and console, a dom0 operating system which mediates access to
   other hardware (e.g., disks, network, USB), and one or more domU
   operating systems which operate in an unprivileged virtualized
   environment.  IO requests from the domU systems are forwarded by the
   hypervisor (Xen) to the dom0 to be fulfilled.
   Xen supports two styles of guests.  The original is Para-Virtualized
   (PV) which means that the guest OS does not attempt to access hardware
   directly, but instead makes hypercalls to the hypervisor.  This is
   analogous to a user-space program making system calls.  (The dom0
   operating system uses PV calls for some functions, such as updating
   memory mapping page tables, but has direct hardware access for disk
   and network.)   PV guests must be specifically coded for Xen.
   The more recent style is HVM, which means that the guest does not have
   code for Xen and need not be aware that it is running under Xen.
   Attempts to access hardware registers are trapped and emulated.  This
   style is less efficient but can run unmodified guests.
   Generally any amd64 machine will work with Xen and PV guests.  In
   theory i386 computers without amd64 support can be used for Xen <=
   4.2, but we have no recent reports of this working (this is a hint).
   For HVM guests, the VT or VMX cpu feature (Intel) or SVM/HVM/VT
   (amd64) is needed; "cpuctl identify 0" will show this.  TODO: Clean up
   and check the above features.
   At boot, the dom0 kernel is loaded as a module with Xen as the kernel.
   The dom0 can start one or more domUs.  (Booting is explained in detail
   in the dom0 section.)
   NetBSD supports Xen in that it can serve as dom0, be used as a domU,
   and that Xen kernels and tools are available in pkgsrc.  This HOWTO
   attempts to address both the case of running a NetBSD dom0 on hardware
   and running domUs under it (NetBSD and other), and also running NetBSD
   as a domU in a VPS.
   Some versions of Xen support "PCI passthrough", which means that
   specific PCI devices can be made available to a specific domU instead
   of the dom0.  This can be useful to let a domU run X11, or access some
   network interface or other peripheral.
   NetBSD used to support Xen2; this has been removed.
   Installing NetBSD/Xen is not extremely difficult, but it is more
   complex than a normal installation of NetBSD.
   In general, this HOWTO is occasionally overly restrictive about how
   things must be done, guiding the reader to stay on the established
   path when there are no known good reasons to stray.
   This HOWTO presumes a basic familiarity with the Xen system
   architecture.  This HOWTO presumes familiarity with installing NetBSD
   on i386/amd64 hardware and installing software from pkgsrc.
   See also the [Xen website](http://www.xenproject.org/).
   Versions of Xen and NetBSD
   Most of the installation concepts and instructions are independent
   of Xen version and NetBSD version.  This section gives advice on
   which version to choose.  Versions not in pkgsrc and older unsupported
   versions of NetBSD are intentionally ignored.
   In NetBSD, xen is provided in pkgsrc, via matching pairs of packages
   xenkernel and xentools.  We will refer only to the kernel versions,
   but note that both packages must be installed together and must have
   matching versions.
   xenkernel3 and xenkernel33 provide Xen 3.1 and 3.3.  These no longer
   receive security patches and should not be used.  Xen 3.1 supports PCI
   passthrough.  Xen 3.1 supports non-PAE on i386.
   xenkernel41 provides Xen 4.1.  This is no longer maintained by Xen,
   but as of 2014-12 receives backported security patches.  It is a
   reasonable although trailing-edge choice.
   xenkernel42 provides Xen 4.2.  This is maintained by Xen, but old as
   of 2014-12.
   Ideally newer versions of Xen will be added to pkgsrc.
   Note that NetBSD support is called XEN3.  It works with 3.1 through
   4.2 because the hypercall interface has been stable.
   Xen command program
   Early Xen used a program called "xm" to manipulate the system from the
   dom0.  Starting in 4.1, a replacement program with similar behavior
   called "xl" is provided.  In 4.2 and later, "xl" is preferred.  4.4 is
   the last version that has "xm".
   The netbsd-5, netbsd-6, netbsd-7, and -current branches are all
   reasonable choices, with more or less the same considerations for
   non-Xen use.  Therefore, netbsd-6 is recommended as the stable version
   of the most recent release for production use.  For those wanting to
   learn Xen or without production stability concerns, netbsd-7 is likely
   most appropriate.
   As of NetBSD 6, a NetBSD domU will support multiple vcpus.  There is
   no SMP support for NetBSD as dom0.  (The dom0 itself doesn't really
   need SMP; the lack of support is really a problem when using a dom0 as
   a normal computer.)
   Xen itself can run on i386 or amd64 machines.  (Practically, almost
   any computer where one would want to run Xen supports amd64.)  If
   using an i386 NetBSD kernel for the dom0, PAE is required (PAE
   versions are built by default).  While i386 dom0 works fine, amd64 is
   recommended as more normal.
   Xen 4.2 is the last version to support i386 as a host.  TODO: Clarify
   if this is about the CPU having to be amd64, or about the dom0 kernel
   having to be amd64.
   One can then run i386 domUs and amd64 domUs, in any combination.  If
   running an i386 NetBSD kernel as a domU, the PAE version is required.
   (Note that emacs (at least) fails if run on i386 with PAE when built
   without, and vice versa, presumably due to bugs in the undump code.)
   Therefore, this HOWTO recommends running xenkernel42 (and xentools42),
   xl, the NetBSD 6 stable branch, and to use an amd64 kernel as the
   dom0.  Either the i386 or amd64 of NetBSD may be used as domUs.
   Build problems
   Ideally, all versions of Xen in pkgsrc would build on all versions of
   NetBSD on both i386 and amd64.  However, that isn't the case.  Besides
   aging code and aging compilers, qemu (included in xentools for HVM
   support) is difficult to build.  The following are known to work or FAIL:
           xenkernel3 netbsd-5 amd64
           xentools3 netbsd-5 amd64
           xentools3=hvm netbsd-5 amd64 ????
           xenkernel33 netbsd-5 amd64
           xentools33 netbsd-5 amd64
           xenkernel41 netbsd-5 amd64
           xentools41 netbsd-5 amd64
           xenkernel42 netbsd-5 amd64
           xentools42 netbsd-5 amd64
           xenkernel3 netbsd-6 i386 FAIL
           xentools3 netbsd-6 i386
           xentools3-hvm netbsd-6 i386 FAIL (dependencies fail)
           xenkernel33 netbsd-6 i386
           xentools33 netbsd-6 i386
           xenkernel41 netbsd-6 i386
           xentools41 netbsd-6 i386
           xenkernel42 netbsd-6 i386
           xentools42 netbsd-6 i386 *MIXED
           (all 3 and 33 seem to FAIL)
           xenkernel41 netbsd-7 i386
           xentools41 netbsd-7 i386
           xenkernel42 netbsd-7 i386
           xentools42 netbsd-7 i386 ??FAIL
 -   [Introduction](#introduction)  (*On netbsd-6 i386, there is a xentools42 in the 2014Q3 official builds,
 -   [Installing NetBSD as privileged domain (Dom0)](#netbsd-dom0)  but it does not build for gdt.)
 -   [Creating an unprivileged NetBSD domain (DomU)](#netbsd-domU)  
 -   [Creating an unprivileged Linux domain (DomU)](#linux-domU)  
 -   [Creating an unprivileged Solaris domain (DomU)](#solaris-domU)  
 -   [Using PCI devices in guest domains](#pci-pass-through)  
 -   [Links and further information](#links-and-more)  
 * * * * *  NetBSD as a dom0
 ### Introduction  NetBSD can be used as a dom0 and works very well.  The following
   sections address installation, updating NetBSD, and updating Xen.
   Note that it doesn't make sense to talk about installing a dom0 OS
   without also installing Xen itself.  We first address installing
   NetBSD, which is not yet a dom0, and then adding Xen, pivoting the
   NetBSD install to a dom0 install by just changing the kernel and boot
   For experimenting with Xen, a machine with as little as 1G of RAM and
   100G of disk can work.  For running many domUs in productions, far
   more will be needed.
   Styles of dom0 operation
   There are two basic ways to use Xen.  The traditional method is for
   the dom0 to do absolutely nothing other than providing support to some
   number of domUs.  Such a system was probably installed for the sole
   purpose of hosting domUs, and sits in a server room on a UPS.
   The other way is to put Xen under a normal-usage computer, so that the
   dom0 is what the computer would have been without Xen, perhaps a
   desktop or laptop.  Then, one can run domUs at will.  Purists will
   deride this as less secure than the previous approach, and for a
   computer whose purpose is to run domUs, they are right.  But Xen and a
   dom0 (without domUs) is not meaingfully less secure than the same
   things running without Xen.  One can boot Xen or boot regular NetBSD
   alternately with little problems, simply refraining from starting the
   Xen daemons when not running Xen.
   Note that NetBSD as dom0 does not support multiple CPUs.  This will
   limit the performance of the Xen/dom0 workstation approach.  In theory
   the only issue is that the "backend drivers" are not yet MPSAFE:
   Installation of NetBSD
   [install NetBSD/amd64](/guide/inst/)
   just as you would if you were not using Xen.
   However, the partitioning approach is very important.
   If you want to use RAIDframe for the dom0, there are no special issues
   for Xen.  Typically one provides RAID storage for the dom0, and the
   domU systems are unaware of RAID.  The 2nd-stage loader bootxx_* skips
   over a RAID1 header to find /boot from a filesystem within a RAID
   partition; this is no different when booting Xen.
   There are 4 styles of providing backing storage for the virtual disks
   used by domUs: raw partitions, LVM, file-backed vnd(4), and SAN,
   With raw partitions, one has a disklabel (or gpt) partition sized for
   each virtual disk to be used by the domU.  (If you are able to predict
   how domU usage will evolve, please add an explanation to the HOWTO.
   Seriously, needs tend to change over time.)
   One can use [lvm(8)](/guide/lvm/) to create logical devices to use
   for domU disks.  This is almost as efficient as raw disk partitions
   and more flexible.  Hence raw disk partitions should typically not
   be used.
   One can use files in the dom0 filesystem, typically created by dd'ing
   /dev/zero to create a specific size.  This is somewhat less efficient,
   but very convenient, as one can cp the files for backup, or move them
   between dom0 hosts.
   Finally, in theory one can place the files backing the domU disks in a
   SAN.  (This is an invitation for someone who has done this to add a
   HOWTO page.)
   Installation of Xen
   In the dom0, install sysutils/xenkernel42 and sysutils/xentools42 from
   pkgsrc (or another matching pair).
   See [the pkgsrc
   documentation](http://www.NetBSD.org/docs/pkgsrc/) for help with pkgsrc.
   For Xen 3.1, support for HVM guests is in sysutils/xentool3-hvm.  More
   recent versions have HVM support integrated in the main xentools
   package.  It is entirely reasonable to run only PV guests.
   Next you need to install the selected Xen kernel itself, which is
   installed by pkgsrc as "/usr/pkg/xen*-kernel/xen.gz".  Copy it to /.
   For debugging, one may copy xen-debug.gz; this is conceptually similar
   to DIAGNOSTIC and DEBUG in NetBSD.  xen-debug.gz is basically only
   useful with a serial console.  Then, place a NetBSD XEN3_DOM0 kernel
   in /, copied from releasedir/amd64/binary/kernel/netbsd-XEN3_DOM0.gz
   of a NetBSD build.  Both xen and NetBSD may be left compressed.  (If
   using i386, use releasedir/i386/binary/kernel/netbsd-XEN3PAE_DOM0.gz.)
   With Xen as the kernel, you must provide a dom0 NetBSD kernel to be
   used as a module; place this in /.  Suitable kernels are provided in
           i386 XEN3_DOM0
           i386 XEN3PAE_DOM0
           amd64 XEN3_DOM0
   The first one is only for use with Xen 3.1 and i386-mode Xen (and you
   should not do this).  Current Xen always uses PAE on i386, but you
   should generally use amd64 for the dom0.  In a dom0 kernel, kernfs is
   mandatory for xend to comunicate with the kernel, so ensure that /kern
   is in fstab.  TODO: Say this is default, or file a PR and give a
   Because you already installed NetBSD, you have a working boot setup
   with an MBR bootblock, either bootxx_ffsv1 or bootxx_ffsv2 at the
   beginning of your root filesystem, /boot present, and likely
   /boot.cfg.  (If not, fix before continuing!)
   See boot.cfg(5) for an example.  The basic line is
           menu=Xen:load /netbsd-XEN3_DOM0.gz console=pc;multiboot /xen.gz dom0_mem=256M
   which specifies that the dom0 should have 256M, leaving the rest to be
   allocated for domUs.  In an attempt to add performance, one can also
           dom0_max_vcpus=1 dom0_vcpus_pin
   to force only one vcpu to be provided (since NetBSD dom0 can't use
   more) and to pin that vcpu to a physical cpu.  TODO: benchmark this.
   As with non-Xen systems, you should have a line to boot /netbsd (a
   kernel that works without Xen) and fallback versions of the non-Xen
   kernel, Xen, and the dom0 kernel.
   Using grub (historic)
   Before NetBSD's native bootloader could support Xen, the use of
   grub was recommended.  If necessary, see the
   [old grub information](/ports/xen/howto-grub/).
   The [HowTo on Installing into
   explains how to set up booting a dom0 with Xen using grub with
   NetBSD's RAIDframe.  (This is obsolete with the use of NetBSD's native
   Configuring Xen
   Xen logs will be in /var/log/xen.
   Now, you have a system that will boot Xen and the dom0 kernel, and
   just run the dom0 kernel.  There will be no domUs, and none can be
   started because you still have to configure the dom0 tools.  The
   daemons which should be run vary with Xen version and with whether one
   is using xm or xl.  Note that xend is for supporting "xm", and should
   only be used if you plan on using "xm".  Do NOT enable xend if you
   plan on using "xl" as it will cause problems.
   The installation of NetBSD should already have created devices for xen
   (xencons, xenevt), but if they are not present, create them:
           cd /dev && sh MAKEDEV xen
   TODO: Give 3.1 advice (or remove it from pkgsrc).
   For 3.3 (and thus xm), add to rc.conf (but note that you should have
   installed 4.1 or 4.2):
   For 4.1 (and thus xm; xl is believed not to work well), add to rc.conf:
   (If you are using xentools41 from before 2014-12-26, change
   rc.d/xendomains to use xm rather than xl.)
   For 4.2 with xm, add to rc.conf
   For 4.2 with xl (preferred), add to rc.conf:
           TODO: explain if there is a xend replacement
   TODO: Recommend for/against xen-watchdog.
   After you have configured the daemons and either started them (in the
   order given) or rebooted, run the following (or use xl) to inspect
   Xen's boot messages, available resources, and running domains:
           # xm dmesg
           [xen's boot info]
           # xm info
           [available memory, etc.]
           # xm list
           Name              Id  Mem(MB)  CPU  State  Time(s)  Console
           Domain-0           0       64    0  r----     58.1
   anita (for testing NetBSD)
   With the setup so far, one should be able to run anita (see
   pkgsrc/sysutils/py-anita) to test NetBSD releases, by doing (as root,
   because anita must create a domU):
           anita --vmm=xm test file:///usr/obj/i386/
   Alternatively, one can use --vmm=xl to use xl-based domU creation instead.
   TODO: check this.
   Xen-specific NetBSD issues
   There are (at least) two additional things different about NetBSD as a
   dom0 kernel compared to hardware.
   One is that modules are not usable in DOM0 kernels, so one must
   compile in what's needed.  It's not really that modules cannot work,
   but that modules must be built for XEN3_DOM0 because some of the
   defines change and the normal module builds don't do this.  Basically,
   enabling Xen changes the kernel ABI, and the module build system
   doesn't cope with this.
   The other difference is that XEN3_DOM0 does not have exactly the same
   options as GENERIC.  While it is debatable whether or not this is a
   bug, users should be aware of this and can simply add missing config
   items if desired.
   Updating NetBSD in a dom0
   This is just like updating NetBSD on bare hardware, assuming the new
   version supports the version of Xen you are running.  Generally, one
   replaces the kernel and reboots, and then overlays userland binaries
   and adjusts /etc.
 [![[Xen  Note that one must update both the non-Xen kernel typically used for
 screenshot]](../../gallery/in-Action/hubertf-xens.png)](../../gallery/in-Action/hubertf-xen.png)  rescue purposes and the DOM0 kernel used with Xen.
 Xen is a virtual machine monitor for x86 hardware (requires i686-class  Converting from grub to /boot
 CPUs), which supports running multiple guest operating systems on a  -----------------------------
 single machine. Guest OSes (also called <E2><80><9C>domains<E2><80><9D>) require a modified  
 kernel which supports Xen hypercalls in replacement to access to the  These instructions were [TODO: will be] used to convert a system from
 physical hardware. At boot, the Xen kernel (also known as the Xen  grub to /boot.  The system was originally installed in February of
 hypervisor) is loaded (via the bootloader) along with the guest kernel  2006 with a RAID1 setup and grub to boot Xen 2, and has been updated
 for the first domain (called *domain0*). The Xen kernel has to be loaded  over time.  Before these commands, it was running NetBSD 6 i386, Xen
 using the multiboot protocol. You would use the NetBSD boot loader for  4.1 and grub, much like the message linked earlier in the grub
 this, or alternatively the **grub** boot loader (**grub** has some  section.
 limitations, detailed below). *domain0* has special privileges to access  
 the physical hardware (PCI and ISA devices), administrate other domains          # Install mbr bootblocks on both disks. 
 and provide virtual devices (disks and network) to other domains that          fdisk -i /dev/rwd0d
 lack those privileges. For more details, see          fdisk -i /dev/rwd1d
 [http://www.xen.org/](http://www.xen.org/).          # Install NetBSD primary boot loader (/ is FFSv1) into RAID1 components.
           installboot -v /dev/rwd0d /usr/mdec/bootxx_ffsv1
 NetBSD can be used for both *domain0 (Dom0)* and further, unprivileged          installboot -v /dev/rwd1d /usr/mdec/bootxx_ffsv1
 (DomU) domains. (Actually there can be multiple privileged domains          # Install secondary boot loader
 accessing different parts of the hardware, all providing virtual devices          cp -p /usr/mdec/boot /
 to unprivileged domains. We will only talk about the case of a single          # Create boog.cfg following earlier guidance:
 privileged domain, *domain0*). *domain0* will see physical devices much          menu=Xen:load /netbsd-XEN3PAE_DOM0.gz console=pc;multiboot /xen.gz dom0_mem=256M
 like a regular i386 or amd64 kernel, and will own the physical console          menu=Xen.ok:load /netbsd-XEN3PAE_DOM0.ok.gz console=pc;multiboot /xen.ok.gz dom0_mem=256M
 (VGA or serial). Unprivileged domains will only see a character-only          menu=GENERIC:boot
 virtual console, virtual disks (`xbd`{.code}) and virtual network          menu=GENERIC single-user:boot -s
 interfaces (`xennet`{.code}) provided by a privileged domain (usually          menu=GENERIC.ok:boot netbsd.ok
 *domain0*). xbd devices are connected to a block device (i.e., a          menu=GENERIC.ok single-user:boot netbsd.ok -s
 partition of a disk, raid, ccd, ... device) in the privileged domain.          menu=Drop to boot prompt:prompt
 xennet devices are connected to virtual devices in the privileged          default=1
 domain, named xvif\<domain number\>.\<if number for this domain\>, e.g.,          timeout=30
 xvif1.0. Both xennet and xvif devices are seen as regular Ethernet  
 devices (they can be seen as a crossover cable between 2 PCs) and can be  TODO: actually do this and fix it if necessary.
 assigned addresses (and be routed or NATed, filtered using IPF, etc ...)  
 or be added as part of a bridge.  Updating Xen versions
 * * * * *  
 ### Installing NetBSD as privileged domain (Dom0)  Updating Xen is conceptually not difficult, but can run into all the
   issues found when installing Xen.  Assuming migration from 4.1 to 4.2,
 First do a NetBSD/i386 or NetBSD/amd64  remove the xenkernel41 and xentools41 packages and install the
 [installation](../../docs/guide/en/chap-inst.html) of the 5.1 release  xenkernel42 and xentools42 packages.  Copy the 4.2 xen.gz to /.
 (or newer) as you usually do on x86 hardware. The binary releases are  
 available from  Ensure that the contents of /etc/rc.d/xen* are correct.  Enable the
 [ftp://ftp.NetBSD.org/pub/NetBSD/](ftp://ftp.NetBSD.org/pub/NetBSD/).  correct set of daemons.  Ensure that the domU config files are valid
 Binary snapshots for current and the stable branches are available on  for the new version.
 [daily autobuilds](http://nyftp.NetBSD.org/pub/NetBSD-daily/). If you  
 plan to use the **grub** boot loader, when partitioning the disk you  
 have to make the root partition smaller than 512Mb, and formatted as  Unprivileged domains (domU)
 FFSv1 with 8k block/1k fragments. If the partition is larger than this,  ===========================
 uses FFSv2 or has different block/fragment sizes, grub may fail to load  
 some files. Also keep in mind that you'll probably want to provide  This section describes general concepts about domUs.  It does not
 virtual disks to other domains, so reserve some partitions for these  address specific domU operating systems or how to install them.  The
 virtual disks. Alternatively, you can create large files in the file  config files for domUs are typically in /usr/pkg/etc/xen, and are
 system, map them to vnd(4) devices and export theses vnd devices to  typically named so that the file name, domU name and the domU's host
 other domains.  name match.
 Next step is to install the Xen packages via pkgsrc or from binary  The domU is provided with cpu and memory by Xen, configured by the
 packages. See [the pkgsrc  dom0.  The domU is provided with disk and network by the dom0,
 documentation](http://www.NetBSD.org/docs/pkgsrc/) if you are unfamiliar  mediated by Xen, and configured in the dom0.
 with pkgsrc and/or handling of binary packages. Xen 3.1, 3.3, 4.1 and  
 4.2 are available. 3.1 supports PCI pass-through while other versions do  Entropy in domUs can be an issue; physical disks and network are on
 not. You'll need either  the dom0.  NetBSD's /dev/random system works, but is often challenged.
 and  Config files
 [`sysutils/xenkernel3`{.filename}](http://ftp.NetBSD.org/pub/pkgsrc/current/pkgsrc/sysutils/xenkernel3/README.html)  ------------
 for Xen 3.1,  
 [`sysutils/xentools33`{.filename}](http://ftp.NetBSD.org/pub/pkgsrc/current/pkgsrc/sysutils/xentools33/README.html)  There is no good order to present config files and the concepts
 and  surrounding what is being configured.  We first show an example config
 [`sysutils/xenkernel33`{.filename}](http://ftp.NetBSD.org/pub/pkgsrc/current/pkgsrc/sysutils/xenkernel33/README.html)  file, and then in the various sections give details.
 for Xen 3.3,  
 [`sysutils/xentools41`{.filename}](http://ftp.NetBSD.org/pub/pkgsrc/current/pkgsrc/sysutils/xentools41/README.html)  See (at least in xentools41) /usr/pkg/share/examples/xen/xmexample*,
 and  for a large number of well-commented examples, mostly for running
 [`sysutils/xenkernel41`{.filename}](http://ftp.NetBSD.org/pub/pkgsrc/current/pkgsrc/sysutils/xenkernel41/README.html)  GNU/Linux.
 for Xen 4.1. or  
 [`sysutils/xentools42`{.filename}](http://ftp.NetBSD.org/pub/pkgsrc/current/pkgsrc/sysutils/xentools42/README.html)  The following is an example minimal domain configuration file
 and  "/usr/pkg/etc/xen/foo".  It is (with only a name change) an actual
 [`sysutils/xenkernel42`{.filename}](http://ftp.NetBSD.org/pub/pkgsrc/current/pkgsrc/sysutils/xenkernel42/README.html)  known working config file on Xen 4.1 (NetBSD 5 amd64 dom0 and NetBSD 5
 for Xen 4.2. You'll also need  i386 domU).  The domU serves as a network file server.
 if you plan do use the grub boot loader. If using Xen 3.1, you may also          # -*- mode: python; -*-
 want to install  
 [`sysutils/xentools3-hvm`{.filename}](http://ftp.NetBSD.org/pub/pkgsrc/current/pkgsrc/sysutils/xentools3-hvm/README.html)          kernel = "/netbsd-XEN3PAE_DOMU-i386-foo.gz"
 which contains the utilities to run unmodified guests OSes using the          memory = 1024
 *HVM* support (for later versions this is included in          vif = [ 'mac=aa:00:00:d1:00:09,bridge=bridge0' ]
 [`sysutils/xentools`{.filename}](http://ftp.NetBSD.org/pub/pkgsrc/current/pkgsrc/sysutils/xentools/README.html)).          disk = [ 'file:/n0/xen/foo-wd0,0x0,w',
 Note that your CPU needs to support this. Intel CPUs must have the 'VT'                   'file:/n0/xen/foo-wd1,0x1,w' ]
 instruction, AMD CPUs the 'SVM' instruction. You can easily find out if  
 your CPU support HVM by using NetBSD's cpuctl command:  The domain will have the same name as the file.  The kernel has the
   host/domU name in it, so that on the dom0 one can update the various
     # cpuctl identify 0  domUs independently.  The vif line causes an interface to be provided,
     cpu0: Intel Core 2 (Merom) (686-class), id 0x6f6  with a specific mac address (do not reuse MAC addresses!), in bridge
     cpu0: features 0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR>  mode.  Two disks are provided, and they are both writable; the bits
     cpu0: features 0xbfebfbff<PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX>  are stored in files and Xen attaches them to a vnd(4) device in the
     cpu0: features 0xbfebfbff<FXSR,SSE,SSE2,SS,HTT,TM,SBF>  dom0 on domain creation.  The system treates xbd0 as the boot device
     cpu0: features2 0x4e33d<SSE3,DTES64,MONITOR,DS-CPL,VMX,TM2,SSSE3,CX16,xTPR,PDCM,DCA>  without needing explicit configuration.
     cpu0: features3 0x20100800<SYSCALL/SYSRET,XD,EM64T>  
     cpu0: "Intel(R) Xeon(R) CPU            5130  @ 2.00GHz"  By default xm looks for domain config files in /usr/pkg/etc/xen.  Note
     cpu0: I-cache 32KB 64B/line 8-way, D-cache 32KB 64B/line 8-way  that "xm create" takes the name of a config file, while other commands
     cpu0: L2 cache 4MB 64B/line 16-way  take the name of a domain.  To create the domain, connect to the
     cpu0: ITLB 128 4KB entries 4-way  console, create the domain while attaching the console, shutdown the
     cpu0: DTLB 256 4KB entries 4-way, 32 4MB entries 4-way  domain, and see if it has finished stopping, do (or xl with Xen >=
     cpu0: Initial APIC ID 0  4.2):
     cpu0: Cluster/Package ID 0  
     cpu0: Core ID 0          xm create foo
     cpu0: family 06 model 0f extfamily 00 extmodel 00          xm console foo
           xm create -c foo
 Depending on your CPU, the feature you are looking for is called HVM,          xm shutdown foo
 SVM or VMX.          xm list
 Next you need to copy the selected Xen kernel itself. pkgsrc installed  Typing ^] will exit the console session.  Shutting down a domain is
 them under `/usr/pkg/xen*-kernel/`{.filename}. The file you're looking  equivalent to pushing the power button; a NetBSD domU will receive a
 for is `xen.gz`{.filename}. Copy it to your root file system.  power-press event and do a clean shutdown.  Shutting down the dom0
 `xen-debug.gz`{.filename} is a kernel with more consistency checks and  will trigger controlled shutdowns of all configured domUs.
 more details printed on the serial console. It is useful for debugging  
 crashing guests if you use a serial console. It is not useful with a VGA  domU kernels
 console.  ------------
 You'll then need a NetBSD/Xen kernel for *domain0* on your root file  On a physical computer, the BIOS reads sector 0, and a chain of boot
 system. The XEN3PAE\_DOM0 kernel or XEN3\_DOM0 provided as part of the  loaders finds and loads a kernel.  Normally this comes from the root
 i386 or amd64 binaries is suitable for this, but you may want to  filesystem.  With Xen domUs, the process is totally different.  The
 customize it. Keep your native kernel around, as it can be useful for  normal path is for the domU kernel to be a file in the dom0's
 recovery. *Note:* the *domain0* kernel must support KERNFS and  filesystem.  At the request of the dom0, Xen loads that kernel into a
 `/kern`{.filename} must be mounted because *xend* needs access to  new domU instance and starts execution.  While domU kernels can be
 `/kern/xen/privcmd`{.filename}.  anyplace, reasonable places to store domU kernels on the dom0 are in /
   (so they are near the dom0 kernel), in /usr/pkg/etc/xen (near the
 Next you need to get a bootloader to load the `xen.gz`{.filename}  config files), or in /u0/xen (where the vdisks are).
 kernel, and the NetBSD *domain0* kernel as a module. This can be  
 **grub** or NetBSD's boot loader. Below is a detailled example for grub,  Note that loading the domU kernel from the dom0 implies that boot
 see the boot.cfg(5) manual page for an example using the latter.  blocks, /boot, /boot.cfg, and so on are all ignored in the domU.
   See the VPS section near the end for discussion of alternate ways to
 This is also where you'll specify the memory allocated to *domain0*, the  obtain domU kernels.
 console to use, etc ...  
   CPU and memory
 Here is a commented `/grub/menu.lst`{.filename} file:  --------------
 #Grub config file for NetBSD/xen. Copy as /grub/menu.lst and run  A domain is provided with some number of vcpus, less than the number
     # grub-install /dev/rwd0d (assuming your boot device is wd0).  of cpus seen by the hypervisor.  (For a dom0, this is controlled by
     #  the boot argument "dom0_max_vcpus=1".)  For a domU, it is controlled
     # The default entry to load will be the first one  from the config file by the "vcpus = N" directive.
       A domain is provided with memory; this is controlled in the config
     # boot the default entry after 10s if the user didn't hit keyboard  file by "memory = N" (in megabytes).  In the straightforward case, the
     timeout=10  sum of the the memory allocated to the dom0 and all domUs must be less
       than the available memory.
     # Configure serial port to use as console. Ignore if you'll use VGA only  
     serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1  Xen also provides a "balloon" driver, which can be used to let domains
       use more memory temporarily.  TODO: Explain better, and explain how
     # Let the user select which console to use (serial or VGA), default  well it works with NetBSD.
     # to serial after 10s  
     terminal --timeout=10 serial console  Virtual disks
     # An entry for NetBSD/xen, using /netbsd as the domain0 kernel, and serial  
     # console. Domain0 will have 64MB RAM allocated.  With the file/vnd style, typically one creates a directory,
     # Assume NetBSD is installed in the first MBR partition.  e.g. /u0/xen, on a disk large enough to hold virtual disks for all
     title Xen 3 / NetBSD (hda0, serial)  domUs.  Then, for each domU disk, one writes zeros to a file that then
       root(hd0,0)  serves to hold the virtual disk's bits; a suggested name is foo-xbd0
       kernel (hd0,a)/xen.gz dom0_mem=65536 com1=115200,8n1  for the first virtual disk for the domU called foo.  Writing zeros to
       module (hd0,a)/netbsd bootdev=wd0a ro console=ttyS0  the file serves two purposes.  One is that preallocating the contents
       improves performance.  The other is that vnd on sparse files has
     # Same as above, but using VGA console  failed to work.  TODO: give working/notworking NetBSD versions for
     # We can use console=tty0 (Linux syntax) or console=pc (NetBSD syntax)  sparse vnd.  Note that the use of file/vnd for Xen is not really
     title Xen 3 / NetBSD (hda0, vga)  different than creating a file-backed virtual disk for some other
       root(hd0,0)  purpose, except that xentools handles the vnconfig commands.  To
       kernel (hd0,a)/xen.gz dom0_mem=65536  create an empty 4G virtual disk, simply do
       module (hd0,a)/netbsd bootdev=wd0a ro console=tty0  
               dd if=/dev/zero of=foo-xbd0 bs=1m count=4096
     # NetBSD/xen using a backup domain0 kernel (in case you installed a  
     # nonworking kernel as /netbsd  With the lvm style, one creates logical devices.  They are then used
     title Xen 3 / NetBSD (hda0, backup, serial)  similarly to vnds.  TODO: Add an example with lvm.
       kernel (hd0,a)/xen.gz dom0_mem=65536 com1=115200,8n1  In domU config files, the disks are defined as a sequence of 3-tuples.
       module (hd0,a)/netbsd.backup bootdev=wd0a ro console=ttyS0  The first element is "method:/path/to/disk".  Common methods are
     title Xen 3 / NetBSD (hda0, backup, VGA)  "file:" for file-backed vnd. and "phy:" for something that is already
       root(hd0,0)  a (TODO: character or block) device.
       kernel (hd0,a)/xen.gz dom0_mem=65536  
       module (hd0,a)/netbsd.backup bootdev=wd0a ro console=tty0  The second element is an artifact of how virtual disks are passed to
       Linux, and a source of confusion with NetBSD Xen usage.  Linux domUs
     #Load a regular NetBSD/i386 kernel. Can be useful if you end up with a  are given a device name to associate with the disk, and values like
     #nonworking /xen.gz  "hda1" or "sda1" are common.  In a NetBSD domU, the first disk appears
     title NetBSD 5.1  as xbd0, the second as xbd1, and so on.  However, xm/xl demand a
       root (hd0,a)  second argument.  The name given is converted to a major/minor by
       kernel --type=netbsd /netbsd-GENERIC  calling stat(2) on the name in /dev and this is passed to the domU.
       In the general case, the dom0 and domU can be different operating
     #Load the NetBSD bootloader, letting it load the NetBSD/i386 kernel.  systems, and it is an unwarranted assumption that they have consistent
     #May be better than the above, as grub can't pass all required infos  numbering in /dev, or even that the dom0 OS has a /dev.  With NetBSD
     #to the NetBSD/i386 kernel (e.g. console, root device, ...)  as both dom0 and domU, using values of 0x0 for the first disk and 0x1
     title NetBSD chain  for the second works fine and avoids this issue.  For a GNU/Linux
       root        (hd0,0)  guest, one can create /dev/hda1 in /dev, or to pass 0x301 for
       chainloader +1  /dev/hda1.
     ## end of grub config file.  The third element is "w" for writable disks, and "r" for read-only
 Install grub with the following command:  
   Virtual Networking
     # grub --no-floppy  ------------------
     grub> root (hd0,a)  Xen provides virtual ethernets, each of which connects the dom0 and a
      Filesystem type is ffs, partition type 0xa9  domU.  For each virtual network, there is an interface "xvifN.M" in
       the dom0, and in domU index N, a matching interface xennetM (NetBSD
     grub> setup (hd0)  name).  The interfaces behave as if there is an Ethernet with two
      Checking if "/boot/grub/stage1" exists... no  adaptors connected.  From this primitive, one can construct various
      Checking if "/grub/stage1" exists... yes  configurations.  We focus on two common and useful cases for which
      Checking if "/grub/stage2" exists... yes  there are existing scripts: bridging and NAT.
      Checking if "/grub/ffs_stage1_5" exists... yes  
      Running "embed /grub/ffs_stage1_5 (hd0)"...  14 sectors are embedded.  With bridging (in the example above), the domU perceives itself to be
     succeeded  on the same network as the dom0.  For server virtualization, this is
      Running "install /grub/stage1 (hd0) (hd0)1+14 p (hd0,0,a)/grub/stage2 /grub/menu.lst"...  usually best.  Bridging is accomplished by creating a bridge(4) device
      succeeded  and adding the dom0's physical interface and the various xvifN.0
     Done.  interfaces to the bridge.  One specifies "bridge=bridge0" in the domU
   config file.  The bridge must be set up already in the dom0; an
 * * * * *  example /etc/ifconfig.bridge0 is:
 ### Creating an unprivileged NetBSD domain (DomU)          create
 Once you have *domain0* running, you need to start the xen tool daemon          !brconfig bridge0 add wm0
 (**/usr/pkg/share/examples/rc.d/xend start**) and the xen backend daemon  
 (**/usr/pkg/share/examples/rc.d/xenbackendd start** for Xen3\*,  With NAT, the domU perceives itself to be behind a NAT running on the
 **/usr/pkg/share/examples/rc.d/xencommons start** for Xen4.\*). Make  dom0.  This is often appropriate when running Xen on a workstation.
 sure that `/dev/xencons`{.filename} and `/dev/xenevt`{.filename} exist  TODO: NAT appears to be configured by "vif = [ '' ]".
 before starting **xend**. You can create them with this command:  
   The MAC address specified is the one used for the interface in the new
     # cd /dev && sh MAKEDEV xen  domain.  The interface in dom0 will use this address XOR'd with
   00:00:00:01:00:00.  Random MAC addresses are assigned if not given.
 xend will write logs to `/var/log/xend.log`{.filename} and  
 `/var/log/xend-debug.log`{.filename}. You can then control xen with the  Sizing domains
 xm tool. 'xm list' will show something like:  --------------
     # xm list  Modern x86 hardware has vast amounts of resources.  However, many
     Name              Id  Mem(MB)  CPU  State  Time(s)  Console  virtual servers can function just fine on far less.  A system with
     Domain-0           0       64    0  r----     58.1  256M of RAM and a 4G disk can be a reasonable choice.  Note that it is
   far easier to adjust virtual resources than physical ones.  For
 'xm create' allows you to create a new domain. It uses a config file in  memory, it's just a config file edit and a reboot.  For disk, one can
 PKG\_SYSCONFDIR for its parameters. By default, this file will be in  create a new file and vnconfig it (or lvm), and then dump/restore,
 `/usr/pkg/etc/xen/`{.filename}. On creation, a kernel has to be  just like updating physical disks, but without having to be there and
 specified, which will be executed in the new domain (this kernel is in  without those pesky connectors.
 the *domain0* file system, not on the new domain virtual disk; but  
 please note, you should install the same kernel into *domainU* as  Starting domains automatically
 `/netbsd`{.filename} in order to make your system tools, like  ------------------------------
 work). A suitable kernel is provided as part of the i386 and amd64  To start domains foo at bar at boot and shut them down cleanly on dom0
 binary sets: XEN3\_DOMU.  shutdown, in rc.conf add:
 Here is an /usr/pkg/etc/xen/nbsd example config file:          xendomains="foo bar"
     #  -*- mode: python; -*-  TODO: Explain why 4.1 rc.d/xendomains has xl, when one should use xm
     #============================================================================  on 4.1.  Or fix the xentools41 package to have xm
     # Python defaults setup for 'xm create'.  
     # Edit this file to reflect the configuration of your system.  Creating specific unprivileged domains (domU)
     #============================================================================  =============================================
     #----------------------------------------------------------------------------  Creating domUs is almost entirely independent of operating system.  We
     # Kernel image file. This kernel will be loaded in the new domain.  have already presented the basics of config files.  Note that you must
     kernel = "/home/bouyer/netbsd-XEN3_DOMU"  have already completed the dom0 setup so that "xl list" (or "xm list")
     #kernel = "/home/bouyer/netbsd-INSTALL_XEN3_DOMU"  works.
     # Memory allocation (in megabytes) for the new domain.  Creating an unprivileged NetBSD domain (domU)
     memory = 128  ---------------------------------------------
     # A handy name for your new domain. This will appear in 'xm list',  See the earlier config file, and adjust memory.  Decide on how much
     # and you can use this as parameters for xm in place of the domain  storage you will provide, and prepare it (file or lvm).
     # number. All domains must have different names.  
     #  While the kernel will be obtained from the dom0 filesystem, the same
     name = "nbsd"  file should be present in the domU as /netbsd so that tools like
       savecore(8) can work.   (This is helpful but not necessary.)
     # The number of virtual CPUs this domain has.  
     #  The kernel must be specifically for Xen and for use as a domU.  The
     vcpus = 1  i386 and amd64 provide the following kernels:
     #----------------------------------------------------------------------------          i386 XEN3_DOMU
     # Define network interfaces for the new domain.          i386 XEN3PAE_DOMU
               amd64 XEN3_DOMU
     # Number of network interfaces (must be at least 1). Default is 1.  
     nics = 1  Unless using Xen 3.1 (and you shouldn't) with i386-mode Xen, you must
       use the PAE version of the i386 kernel.
     # Define MAC and/or bridge for the network interfaces.  
     #  This will boot NetBSD, but this is not that useful if the disk is
     # The MAC address specified in ``mac'' is the one used for the interface  empty.  One approach is to unpack sets onto the disk outside of xen
     # in the new domain. The interface in domain0 will use this address XOR'd  (by mounting it, just as you would prepare a physical disk for a
     # with 00:00:00:01:00:00 (i.e. aa:00:00:51:02:f0 in our example). Random  system you can't run the installer on).
     # MACs are assigned if not given.  
     #  A second approach is to run an INSTALL kernel, which has a miniroot
     # ``bridge'' is a required parameter, which will be passed to the  and can load sets from the network.  To do this, copy the INSTALL
     # vif-script called by xend(8) when a new domain is created to configure  kernel to / and change the kernel line in the config file to:
     # the new xvif interface in domain0.  
     # In this example, the xvif is added to bridge0, which should have been  
     # set up prior to the new domain being created -- either in the  
     # ``network'' script or using a /etc/ifconfig.bridge0 file.  
     vif = [ 'mac=aa:00:00:50:02:f0, bridge=bridge0' ]  
     # Define the disk devices you want the domain to have access to, and  
     # what you want them accessible as.  
     # Each disk entry is of the form:  
     #       phy:DEV,VDEV,MODE  
     # where DEV is the device, VDEV is the device name the domain will see,  
     # and MODE is r for read-only, w for read-write.  You can also create  
     # file-backed domains using disk entries of the form:  
     #       file:PATH,VDEV,MODE  
     # where PATH is the path to the file used as the virtual disk, and VDEV  
     # and MODE have the same meaning as for ``phy'' devices.  
     # VDEV doesn't really matter for a NetBSD guest OS (it's just used as an index),  
     # but it does for Linux.  
     # Worse, the device has to exist in /dev/ of domain0, because xm will  
     # try to stat() it. This means that in order to load a Linux guest OS  
     # from a NetBSD domain0, you'll have to create /dev/hda1, /dev/hda2, ...  
     # on domain0, with the major/minor from Linux :(  
     # Alternatively it's possible to specify the device number in hex,  
     # e.g. 0x301 for /dev/hda1, 0x302 for /dev/hda2, etc ...  
     disk = [ 'phy:/dev/wd0e,0x1,w' ]  
     #disk = [ 'file:/var/xen/nbsd-disk,0x01,w' ]  
     #disk = [ 'file:/var/xen/nbsd-disk,0x301,w' ]  
     # Set the kernel command line for the new domain.  
     # Set root device. This one does matter for NetBSD  
     root = "xbd0"  
     # extra parameters passed to the kernel  
     # this is where you can set boot flags like -s, -a, etc ...  
     #extra = ""  
     # Set according to whether you want the domain restarted when it exits.  
     # The default is False.  
     #autorestart = True  
     # end of nbsd config file ====================================================  
 When a new domain is created, xen calls the  
 `/usr/pkg/etc/xen/vif-bridge`{.filename} script for each virtual network  
 interface created in *domain0*. This can be used to automatically  
 configure the xvif?.? interfaces in *domain0*. In our example, these  
 will be bridged with the bridge0 device in *domain0*, but the bridge has  
 to exist first. To do this, create the file  
 `/etc/ifconfig.bridge0`{.filename} and make it look like this:  
     !brconfig $int add ex0 up  
 (replace `ex0`{.literal} with the name of your physical interface). Then  
 bridge0 will be created on boot. See the  
 man page for details.  
 So, here is a suitable `/usr/pkg/etc/xen/vif-bridge`{.filename} for  
 xvif?.? (a working vif-bridge is also provided with xentools20)  
     # $NetBSD: howto.mdwn,v 1.2 2013/10/31 12:34:39 mspo Exp $  
     # /usr/pkg/etc/xen/vif-bridge  
     # Script for configuring a vif in bridged mode with a dom0 interface.  
     # The xend(8) daemon calls a vif script when bringing a vif up or down.  
     # The script name to use is defined in /usr/pkg/etc/xen/xend-config.sxp  
     # in the ``vif-script'' field.  
     # Usage: vif-bridge up|down [var=value ...]  
     # Actions:  
     #    up         Adds the vif interface to the bridge.  
     #    down       Removes the vif interface from the bridge.  
     # Variables:  
     #    domain     name of the domain the interface is on (required).  
     #    vifq       vif interface name (required).  
     #    mac        vif MAC address (required).  
     #    bridge     bridge to add the vif to (required).  
     # Example invocation:  
     # vif-bridge up domain=VM1 vif=xvif1.0 mac="ee:14:01:d0:ec:af" bridge=bridge0  
     # Exit if anything goes wrong  
     set -e  
     echo "vif-bridge $*"  
     # Operation name.  
     OP=$1; shift  
     # Pull variables in args into environment  
     for arg ; do export "${arg}" ; done  
     # Required parameters. Fail if not set.  
     # Optional parameters. Set defaults.  
     ip=${ip:-''}   # default to null (do nothing)  
     # Are we going up or down?  
     case $OP in  
     up)     brcmd='add' ;;  
     down)   brcmd='delete' ;;  
             echo 'Invalid command: ' $OP  
             echo 'Valid commands are: up, down'  
             exit 1  
     # Don't do anything if the bridge is "null".  
     if [ "${bridge}" = "null" ] ; then  
     # Don't do anything if the bridge doesn't exist.  
     if ! ifconfig -l | grep "${bridge}" >/dev/null; then  
     # Add/remove vif to/from bridge.  
     ifconfig x${vif} $OP  
     brconfig ${bridge} ${brcmd} x${vif}  
 Now, running  
     xm create -c /usr/pkg/etc/xen/nbsd  
 should create a domain and load a NetBSD kernel in it. (Note:  
 `-c`{.code} causes xm to connect to the domain's console once created.)  
 The kernel will try to find its root file system on xbd0 (i.e., wd0e)  
 which hasn't been created yet. wd0e will be seen as a disk device in the  
 new domain, so it will be 'sub-partitioned'. We could attach a ccd to  
 wd0e in *domain0* and partition it, newfs and extract the NetBSD/i386 or  
 amd64 tarballs there, but there's an easier way: load the  
 `netbsd-INSTALL_XEN3_DOMU`{.filename} kernel provided in the NetBSD  
 binary sets. Like other install kernels, it contains a ramdisk with  
 sysinst, so you can install NetBSD using sysinst on your new domain.  
 If you want to install NetBSD/Xen with a CDROM image, the following line          kernel = "/home/bouyer/netbsd-INSTALL_XEN3_DOMU"
 should be used in the `/usr/pkg/etc/xen/nbsd`{.filename} file:  
   Then, start the domain as "xl create -c configname".
   Alternatively, if you want to install NetBSD/Xen with a CDROM image, the following
   line should be used in the config file.
     disk = [ 'phy:/dev/wd0e,0x1,w', 'phy:/dev/cd0a,0x2,r' ]      disk = [ 'phy:/dev/wd0e,0x1,w', 'phy:/dev/cd0a,0x2,r' ]
 After booting the domain, the option to install via CDROM may be  After booting the domain, the option to install via CDROM may be
 selected. The CDROM device should be changed to **xbd1d**.  selected.  The CDROM device should be changed to `xbd1d`.
 Once done installing, **halt -p** the new domain (don't reboot or halt,  Once done installing, "halt -p" the new domain (don't reboot or halt,
 it would reload the INSTALL\_XEN3\_DOMU kernel even if you changed the  it would reload the INSTALL_XEN3_DOMU kernel even if you changed the
 config file), switch the config file back to the XEN3\_DOMU kernel, and  config file), switch the config file back to the XEN3_DOMU kernel,
 start the new domain again. Now it should be able to use **root on  and start the new domain again. Now it should be able to use "root on
 xbd0a** and you should have a second, functional NetBSD system on your  xbd0a" and you should have a, functional NetBSD domU.
 xen installation.  
   TODO: check if this is still accurate.
 When the new domain is booting you'll see some warnings about *wscons*  When the new domain is booting you'll see some warnings about *wscons*
 and the pseudo-terminals. These can be fixed by editing the files  and the pseudo-terminals. These can be fixed by editing the files
 `/etc/ttys`{.filename} and `/etc/wscons.conf`{.filename}. You must  `/etc/ttys` and `/etc/wscons.conf`. You must disable all terminals in
 disable all terminals in `/etc/ttys`{.filename}, except *console*, like  `/etc/ttys`, except *console*, like this:
     console "/usr/libexec/getty Pc"         vt100   on secure      console "/usr/libexec/getty Pc"         vt100   on secure
     ttyE0   "/usr/libexec/getty Pc"         vt220   off secure      ttyE0   "/usr/libexec/getty Pc"         vt220   off secure
Line 493  this: Line 737  this:
     ttyE2   "/usr/libexec/getty Pc"         vt220   off secure      ttyE2   "/usr/libexec/getty Pc"         vt220   off secure
     ttyE3   "/usr/libexec/getty Pc"         vt220   off secure      ttyE3   "/usr/libexec/getty Pc"         vt220   off secure
 Finally, all screens must be commented out from  Finally, all screens must be commented out from `/etc/wscons.conf`.
 It is also desirable to add  It is also desirable to add
     powerd=YES          powerd=YES
 in rc.conf. This way, the domain will be properly shut down if **xm  in rc.conf. This way, the domain will be properly shut down if
 shutdown -R** or **xm shutdown -H** is used on the domain0.  `xm shutdown -R` or `xm shutdown -H` is used on the dom0.
 Your domain should be now ready to work, enjoy.  Your domain should be now ready to work, enjoy.
 * * * * *  Creating an unprivileged Linux domain (domU)
 ### Creating an unprivileged Linux domain (DomU)  
 Creating unprivileged Linux domains isn't much different from  Creating unprivileged Linux domains isn't much different from
 unprivileged NetBSD domains, but there are some details to know.  unprivileged NetBSD domains, but there are some details to know.
Line 518  the example below) Line 760  the example below)
     disk = [ 'phy:/dev/wd0e,0x1,w' ]      disk = [ 'phy:/dev/wd0e,0x1,w' ]
 does matter to Linux. It wants a Linux device number here (e.g. 0x300  does matter to Linux. It wants a Linux device number here (e.g. 0x300
 for hda). Linux builds device numbers as: (major \<\< 8 + minor). So,  for hda).  Linux builds device numbers as: (major \<\< 8 + minor).
 hda1 which has major 3 and minor 1 on a Linux system will have device  So, hda1 which has major 3 and minor 1 on a Linux system will have
 number 0x301. Alternatively, devices names can be used (hda, hdb, ...)  device number 0x301.  Alternatively, devices names can be used (hda,
 as xentools has a table to map these names to devices numbers. To export  hdb, ...)  as xentools has a table to map these names to devices
 a partition to a Linux guest we can use:  numbers.  To export a partition to a Linux guest we can use:
     disk = [ 'phy:/dev/wd0e,0x300,w' ]          disk = [ 'phy:/dev/wd0e,0x300,w' ]
     root = "/dev/hda1 ro"          root = "/dev/hda1 ro"
 and it will appear as /dev/hda on the Linux system, and be used as root  and it will appear as /dev/hda on the Linux system, and be used as root
 partition.  partition.
 To install the Linux system on the partition to be exported to the guest  To install the Linux system on the partition to be exported to the
 domain, the following method can be used: install sysutils/e2fsprogs  guest domain, the following method can be used: install
 from pkgsrc. Use mke2fs to format the partition that will be the root  sysutils/e2fsprogs from pkgsrc.  Use mke2fs to format the partition
 partition of your Linux domain, and mount it. Then copy the files from a  that will be the root partition of your Linux domain, and mount it.
 working Linux system, make adjustments in `/etc`{.filename} (fstab,  Then copy the files from a working Linux system, make adjustments in
 network config). It should also be possible to extract binary packages  `/etc` (fstab, network config).  It should also be possible to extract
 such as .rpm or .deb directly to the mounted partition using the  binary packages such as .rpm or .deb directly to the mounted partition
 appropriate tool, possibly running under NetBSD's Linux emulation. Once  using the appropriate tool, possibly running under NetBSD's Linux
 the filesystem has been populated, umount it. If desirable, the  emulation.  Once the filesystem has been populated, umount it.  If
 filesystem can be converted to ext3 using tune2fs -j. It should now be  desirable, the filesystem can be converted to ext3 using tune2fs -j.
 possible to boot the Linux guest domain, using one of the  It should now be possible to boot the Linux guest domain, using one of
 vmlinuz-\*-xenU kernels available in the Xen binary distribution.  the vmlinuz-\*-xenU kernels available in the Xen binary distribution.
 To get the linux console right, you need to add:  To get the linux console right, you need to add:
Line 550  To get the linux console right, you need Line 792  To get the linux console right, you need
 to your configuration since not all linux distributions auto-attach a  to your configuration since not all linux distributions auto-attach a
 tty to the xen console.  tty to the xen console.
 * * * * *  Creating an unprivileged Solaris domain (domU)
 ### Creating an unprivileged Solaris domain (DomU)  
 Download an Opensolaris [release](http://opensolaris.org/os/downloads/)  
 or [development snapshot](http://genunix.org/) DVD image. Attach the DVD  
 image to a  
 device. Copy the kernel and ramdisk filesystem image to your dom0  
     dom0# mkdir /root/solaris  
     dom0# vnconfig vnd0 osol-1002-124-x86.iso  
     dom0# mount /dev/vnd0a /mnt  
     ## for a 64-bit guest  
     dom0# cp /mnt/boot/amd64/x86.microroot /root/solaris  
     dom0# cp /mnt/platform/i86xpv/kernel/amd64/unix /root/solaris  
     ## for a 32-bit guest  
     dom0# cp /mnt/boot/x86.microroot /root/solaris  
     dom0# cp /mnt/platform/i86xpv/kernel/unix /root/solaris  
     dom0# umount /mnt  
 Keep the  
 configured. For some reason the boot process stalls unless the DVD image  
 is attached to the guest as a "phy" device. Create an initial  
 configuration file with the following contents. Substitute */dev/wd0k*  
 with an empty partition at least 8 GB large.  
 ~~~ {.programlisting}  
 memory = 640  
 name = 'solaris'  
 disk = [ 'phy:/dev/wd0k,0,w' ]  
 disk += [ 'phy:/dev/vnd0d,6:cdrom,r' ]  
 vif = [ 'bridge=bridge0' ]  
 kernel = '/root/solaris/unix'  
 ramdisk = '/root/solaris/x86.microroot'  
 # for a 64-bit guest  
 extra = '/platform/i86xpv/kernel/amd64/unix - nowin -B install_media=cdrom'  
 # for a 32-bit guest  
 #extra = '/platform/i86xpv/kernel/unix - nowin -B install_media=cdrom'  
 Start the guest.  
 ~~~ {.programlisting}  
 dom0# xm create -c solaris.cfg  
 Started domain solaris  
                       v3.3.2 chgset 'unavailable'  
 SunOS Release 5.11 Version snv_124 64-bit  
 Copyright 1983-2009 Sun Microsystems, Inc.  All rights reserved.  
 Use is subject to license terms.  
 Hostname: opensolaris  
 Remounting root read/write  
 Probing for device nodes ...  
 WARNING: emlxs: ddi_modopen drv/fct failed: err 2  
 Preparing live image for use  
 Done mounting Live image  
 Make sure the network is configured. Note that it can take a minute for  
 the xnf0 interface to appear.  
 ~~~ {.programlisting}  
 opensolaris console login: jack  
 Password: jack  
 Sun Microsystems Inc.   SunOS 5.11      snv_124 November 2008  
 jack@opensolaris:~$ pfexec sh  
 sh-3.2# ifconfig -a  
 sh-3.2# exit  
 Set a password for VNC and start the VNC server which provides the X11  
 display where the installation program runs.  
 ~~~ {.programlisting}  
 jack@opensolaris:~$ vncpasswd  
 Password: solaris  
 Verify: solaris  
 jack@opensolaris:~$ cp .Xclients .vnc/xstartup  
 jack@opensolaris:~$ vncserver :1  
 From a remote machine connect to the VNC server. Use **ifconfig xnf0**  
 on the guest to find the correct IP address to use.  
 ~~~ {.programlisting}  
 remote$ vncviewer  
 It is also possible to launch the installation on a remote X11 display.  
 ~~~ {.programlisting}  
 jack@opensolaris:~$ export DISPLAY=  
 jack@opensolaris:~$ pfexec gui-install  
 After the GUI installation is complete you will be asked to reboot.  
 Before that you need to determine the ZFS ID for the new boot filesystem  
 and update the configuration file accordingly. Return to the guest  
 ~~~ {.programlisting}  
 jack@opensolaris:~$ pfexec zdb -vvv rpool | grep bootfs  
                 bootfs = 43  
 The final configuration file should look like this. Note in particular  
 the last line.  
 ~~~ {.programlisting}  
 memory = 640  
 name = 'solaris'  
 disk = [ 'phy:/dev/wd0k,0,w' ]  
 vif = [ 'bridge=bridge0' ]  
 kernel = '/root/solaris/unix'  
 ramdisk = '/root/solaris/x86.microroot'  
 extra = '/platform/i86xpv/kernel/amd64/unix -B zfs-bootfs=rpool/43,bootpath="/xpvd/xdf@0:a"'  
 Restart the guest to verify it works correctly.  
 ~~~ {.programlisting}  
 dom0# xm destroy solaris  
 dom0# xm create -c solaris.cfg  
 Using config file "./solaris.cfg".  
 v3.3.2 chgset 'unavailable'  
 Started domain solaris  
 SunOS Release 5.11 Version snv_124 64-bit  
 Copyright 1983-2009 Sun Microsystems, Inc.  All rights reserved.  
 Use is subject to license terms.  
 WARNING: emlxs: ddi_modopen drv/fct failed: err 2  
 Hostname: osol  
 Configuring devices.  
 Loading smf(5) service descriptions: 160/160  
 svccfg import warnings. See /var/svc/log/system-manifest-import:default.log .  
 Reading ZFS config: done.  
 Mounting ZFS filesystems: (6/6)  
 Creating new rsa public/private host key pair  
 Creating new dsa public/private host key pair  
 osol console login:  
 Using PCI devices in guest domains  
 The domain0 can give other domains access to selected PCI devices. This  
 can allow, for example, a non-privileged domain to have access to a  
 physical network interface or disk controller. However, keep in mind  
 that giving a domain access to a PCI device most likely will give the  
 domain read/write access to the whole physical memory, as PCs don't have  
 an IOMMU to restrict memory access to DMA-capable device. Also, it's not  
 possible to export ISA devices to non-domain0 domains (which means that  
 the primary VGA adapter can't be exported. A guest domain trying to  
 access the VGA registers will panic).  
 This functionality is only available in NetBSD-5.1 (and later) domain0  
 and domU. If the domain0 is NetBSD, it has to be running Xen 3.1, as  
 support has not been ported to later versions at this time.  
 For a PCI device to be exported to a domU, is has to be attached to the  
 `pciback`{.literal} driver in domain0. Devices passed to the domain0 via  
 the pciback.hide boot parameter will attach to `pciback`{.literal}  
 instead of the usual driver. The list of devices is specified as  
 `(bus:dev.func)`{.literal}, where bus and dev are 2-digit hexadecimal  
 numbers, and func a single-digit number:  
 ~~~ {.programlisting}  
 pciback devices should show up in the domain0's boot messages, and the  
 devices should be listed in the `/kern/xen/pci`{.filename} directory.  
 PCI devices to be exported to a domU are listed in the `pci`{.literal}  
 array of the domU's config file, with the format  
 ~~~ {.programlisting}  
 pci = [ '0000:00:06.0', '0000:00:0a.0' ]  
 In the domU an `xpci`{.literal} device will show up, to which one or  
 more pci busses will attach. Then the PCI drivers will attach to PCI  
 busses as usual. Note that the default NetBSD DOMU kernels do not have  
 `xpci`{.literal} or any PCI drivers built in by default; you have to  
 build your own kernel to use PCI devices in a domU. Here's a kernel  
 config example:  
 ~~~ {.programlisting}  
 include         "arch/i386/conf/XEN3_DOMU"  
 #include         "arch/i386/conf/XENU"           # in NetBSD 3.0  
 # Add support for PCI busses to the XEN3_DOMU kernel  
 xpci* at xenbus ?  
 pci* at xpci ?  
 # Now add PCI and related devices to be used by this domain  
 # USB Controller and Devices  
 # PCI USB controllers  
 uhci*   at pci? dev ? function ?        # Universal Host Controller (Intel)  
 # USB bus support  
 usb*    at uhci?  
 # USB Hubs  
 uhub*   at usb?  
 uhub*   at uhub? port ? configuration ? interface ?  
 # USB Mass Storage  
 umass*  at uhub? port ? configuration ? interface ?  
 wd*     at umass?  
 # SCSI controllers  
 ahc*    at pci? dev ? function ?        # Adaptec [23]94x, aic78x0 SCSI  
 # SCSI bus support (for both ahc and umass)  
 scsibus* at scsi?  
 # SCSI devices  
 sd*     at scsibus? target ? lun ?      # SCSI disk drives  
 cd*     at scsibus? target ? lun ?      # SCSI CD-ROM drives  
 Links and further information  
 -   The HowTo on [Installing into  See possibly outdated
     RAID-1](http://mail-index.NetBSD.org/port-xen/2006/03/01/0010.html)  [Solaris domU instructions](/ports/xen/howto-solaris/).
     gives some hints on using Xen (grub) with NetBSD's RAIDframe  
 -   Harold Gutch wrote documentation on [setting up a Linux DomU with a  
     NetBSD Dom0](http://www.gutch.de/NetBSD/docs/xen.html)  
 -   An example of how to use NetBSD's native bootloader to load  
     NetBSD/Xen instead of Grub can be found in the i386/amd64  
   PCI passthrough: Using PCI devices in guest domains
   The dom0 can give other domains access to selected PCI
   devices. This can allow, for example, a non-privileged domain to have
   access to a physical network interface or disk controller.  However,
   keep in mind that giving a domain access to a PCI device most likely
   will give the domain read/write access to the whole physical memory,
   as PCs don't have an IOMMU to restrict memory access to DMA-capable
   device.  Also, it's not possible to export ISA devices to non-dom0
   domains, which means that the primary VGA adapter can't be exported.
   A guest domain trying to access the VGA registers will panic.
   If the dom0 is NetBSD, it has to be running Xen 3.1, as support has
   not been ported to later versions at this time.
   For a PCI device to be exported to a domU, is has to be attached to
   the "pciback" driver in dom0.  Devices passed to the dom0 via the
   pciback.hide boot parameter will attach to "pciback" instead of the
   usual driver.  The list of devices is specified as "(bus:dev.func)",
   where bus and dev are 2-digit hexadecimal numbers, and func a
   single-digit number:
   pciback devices should show up in the dom0's boot messages, and the
   devices should be listed in the `/kern/xen/pci` directory.
   PCI devices to be exported to a domU are listed in the "pci" array of
   the domU's config file, with the format "0000:bus:dev.func".
           pci = [ '0000:00:06.0', '0000:00:0a.0' ]
   In the domU an "xpci" device will show up, to which one or more pci
   busses will attach.  Then the PCI drivers will attach to PCI busses as
   usual.  Note that the default NetBSD DOMU kernels do not have "xpci"
   or any PCI drivers built in by default; you have to build your own
   kernel to use PCI devices in a domU.  Here's a kernel config example;
   note that only the "xpci" lines are unusual.
           include         "arch/i386/conf/XEN3_DOMU"
           # Add support for PCI busses to the XEN3_DOMU kernel
           xpci* at xenbus ?
           pci* at xpci ?
           # PCI USB controllers
           uhci*   at pci? dev ? function ?        # Universal Host Controller (Intel)
           # USB bus support
           usb*    at uhci?
           # USB Hubs
           uhub*   at usb?
           uhub*   at uhub? port ? configuration ? interface ?
           # USB Mass Storage
           umass*  at uhub? port ? configuration ? interface ?
           wd*     at umass?
           # SCSI controllers
           ahc*    at pci? dev ? function ?        # Adaptec [23]94x, aic78x0 SCSI
           # SCSI bus support (for both ahc and umass)
           scsibus* at scsi?
           # SCSI devices
           sd*     at scsibus? target ? lun ?      # SCSI disk drives
           cd*     at scsibus? target ? lun ?      # SCSI CD-ROM drives
   NetBSD as a domU in a VPS
   The bulk of the HOWTO is about using NetBSD as a dom0 on your own
   hardware.  This section explains how to deal with Xen in a domU as a
   virtual private server where you do not control or have access to the
   VPS operators provide varying degrees of access and mechanisms for
   configuration.  The big issue is usually how one controls which kernel
   is booted, because the kernel is nominally in the dom0 filesystem (to
   which VPS users do not normally have acesss).
   A VPS user may want to compile a kernel for security updates, to run
   npf, run IPsec, or any other reason why someone would want to change
   their kernel.
   One approach is to have an adminstrative interface to upload a kernel,
   or to select from a prepopulated list.  Other approaches are pygrub
   (deprecated) and pvgrub, which are ways to have a bootloader obtain a
   kernel from the domU filesystem.  This is closer to a regular physical
   computer, where someone who controls a machine can replace the kernel.
   pygrub runs in the dom0 and looks into the domU filesystem.  This
   implies that the domU must have a kernel in a filesystem in a format
   known to pygrub.  As of 2014, pygrub seems to be of mostly historical
   pvgrub is a version of grub that uses PV operations instead of BIOS
   calls.  It is booted from the dom0 as the domU kernel, and then reads
   /grub/menu.lst and loads a kernel from the domU filesystem.
   [prgmr.com](http://prgmr.com/) uses this approach to let users choose
   their own operating system and kernel.  See then [prgmr.com NetBSD
   Because [grub's FFS code](http://xenbits.xensource.com/hg/xen-unstable.hg/file/bca284f67702/tools/libfsimage/ufs/fsys_ufs.c)
   appears not to support all aspects of modern FFS,
   typically one has an ext2 or FAT partition for the kernel, so that
   grub can understand it, which leads to /netbsd not being the actual
   kernel.  One must remember to update the special boot partiion.
   TODO: add link to NetBSD amazon howto.
   Using npf
   In standard kernels, npf is a module, and thus cannot be loadeed in a
   DOMU kernel.
   TODO: explain how to compile npf into a custom kernel, answering (but
   note that the problem was caused by not booting the right kernel):
   TODO items for improving NetBSD/xen
   * Package Xen 4.4.
   * Get PCI passthrough working on Xen 4.2 (or 4.4).
   * Get pvgrub into pkgsrc, either via xentools or separately.
   * grub
     * Add support to pkgsrc grub2 for UFS2 and arbitrary
       fragsize/blocksize (UFS2 support may be present; the point is to
       make it so that with any UFS1/UFS2 filesystem setup that works
       with NetBSD grub will also work).
     * Push patches upstream.
     * Get UFS2 patches into pvgrub.
   * Add support for PV ops to a version of /boot, and make it usable as
     a kernel in Xen, similar to pvgrub.

Removed from v.1.3  
changed lines
  Added in v.1.69

CVSweb for NetBSD wikisrc <wikimaster@NetBSD.org> software: FreeBSD-CVSweb