Annotation of wikisrc/ports/xen/howto.mdwn, revision 1.29

1.5       mspo        1: Introduction
1.13      gdt         2: ============
1.1       mspo        3: 
                      4: [![[Xen
1.7       mspo        5: screenshot]](http://www.netbsd.org/gallery/in-Action/hubertf-xens.png)](../../gallery/in-Action/hubertf-xen.png)
1.1       mspo        6: 
1.12      gdt         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: 
1.29    ! gdt        30: Generally any amd64 machine will work with Xen and PV guests.  In
        !            31: theory i386 computers without amd64 support can be used for Xen <=
        !            32: 4.2, but we have no recent reports of this working (this is a hint).
        !            33: For HVM guests, the VT or VMX cpu feature (Intel) or SVM/HVM/VT
        !            34: (amd64) is needed; "cpuctl identify 0" will show this.  TODO: Clean up
        !            35: and check the above features.
1.19      gdt        36: 
1.27      jnemeth    37: At boot, the dom0 kernel is loaded as a module with Xen as the kernel.
1.12      gdt        38: The dom0 can start one or more domUs.  (Booting is explained in detail
                     39: in the dom0 section.)
                     40: 
                     41: NetBSD supports Xen in that it can serve as dom0, be used as a domU,
                     42: and that Xen kernels and tools are available in pkgsrc.  This HOWTO
                     43: attempts to address both the case of running a NetBSD dom0 on hardware
1.24      gdt        44: and running domUs under it (NetBSD and other), and also running NetBSD
                     45: as a domU in a VPS.
1.12      gdt        46: 
1.20      gdt        47: Some versions of Xen support "PCI passthrough", which means that
                     48: specific PCI devices can be made available to a specific domU instead
                     49: of the dom0.  This can be useful to let a domU run X11, or access some
                     50: network interface or other peripheral.
                     51: 
1.12      gdt        52: Prerequisites
1.13      gdt        53: -------------
1.12      gdt        54: 
                     55: Installing NetBSD/Xen is not extremely difficult, but it is more
                     56: complex than a normal installation of NetBSD.
1.15      gdt        57: In general, this HOWTO is occasionally overly restrictive about how
                     58: things must be done, guiding the reader to stay on the established
                     59: path when there are no known good reasons to stray.
1.12      gdt        60: 
                     61: This HOWTO presumes a basic familiarity with the Xen system
1.16      gdt        62: architecture.  This HOWTO presumes familiarity with installing NetBSD
                     63: on i386/amd64 hardware and installing software from pkgsrc.
1.27      jnemeth    64: See also the [Xen website](http://www.xenproject.org/).
1.1       mspo       65: 
1.19      gdt        66: History
                     67: -------
                     68: 
                     69: NetBSD used to support Xen2; this has been removed.
                     70: 
                     71: Before NetBSD's native bootloader could support Xen, the use of
                     72: grub was recommended.  If necessary, see the
1.27      jnemeth    73: [old grub information](/ports/xen/howto-grub/).
1.19      gdt        74: 
1.15      gdt        75: Versions of Xen and NetBSD
                     76: ==========================
                     77: 
1.27      jnemeth    78: Most of the installation concepts and instructions are independent
                     79: of Xen version and NetBSD version.  This section gives advice on
                     80: which version to choose.  Versions not in pkgsrc and older unsupported
                     81: versions of NetBSD are intentionally ignored.
1.15      gdt        82: 
                     83: Xen
                     84: ---
                     85: 
                     86: In NetBSD, xen is provided in pkgsrc, via matching pairs of packages
                     87: xenkernel and xentools.  We will refer only to the kernel versions,
                     88: but note that both packages must be installed together and must have
                     89: matching versions.
                     90: 
                     91: xenkernel3 and xenkernel33 provide Xen 3.1 and 3.3.  These no longer
1.20      gdt        92: receive security patches and should not be used.  Xen 3.1 supports PCI
1.29    ! gdt        93: passthrough.  Xen 3.1 supports non-PAE on i386.
1.15      gdt        94: 
                     95: xenkernel41 provides Xen 4.1.  This is no longer maintained by Xen,
                     96: but as of 2014-12 receives backported security patches.  It is a
                     97: reasonable although trailing-edge choice.
                     98: 
                     99: xenkernel42 provides Xen 4.2.  This is maintained by Xen, but old as
                    100: of 2014-12.
                    101: 
                    102: Ideally newer versions of Xen will be added to pkgsrc.
                    103: 
1.26      gdt       104: Note that NetBSD support is called XEN3.  It works with 3.1 through
                    105: 4.2 because the hypercall interface has been stable.
1.20      gdt       106: 
1.19      gdt       107: Xen command program
                    108: -------------------
                    109: 
                    110: Early Xen used a program called "xm" to manipulate the system from the
                    111: dom0.  Starting in 4.1, a replacement program with similar behavior
1.27      jnemeth   112: called "xl" is provided.  In 4.2 and later, "xl" is preferred.  4.4 is
                    113: the last version that has "xm".
1.19      gdt       114: 
1.15      gdt       115: NetBSD
                    116: ------
                    117: 
                    118: The netbsd-5, netbsd-6, netbsd-7, and -current branches are all
                    119: reasonable choices, with more or less the same considerations for
                    120: non-Xen use.  Therefore, netbsd-6 is recommended as the stable version
1.29    ! gdt       121: of the most recent release for production use.  For those wanting to
        !           122: learn Xen or without production stability concerns, netbsd-7 is likely
        !           123: most appropriate.
1.15      gdt       124: 
                    125: As of NetBSD 6, a NetBSD domU will support multiple vcpus.  There is
                    126: no SMP support for NetBSD as dom0.  (The dom0 itself doesn't really
                    127: need SMP; the lack of support is really a problem when using a dom0 as
                    128: a normal computer.)
                    129: 
1.18      gdt       130: Architecture
                    131: ------------
                    132: 
1.29    ! gdt       133: Xen itself can run on i386 or amd64 machines.  (Practically, almost
        !           134: any computer where one would want to run Xen supports amd64.)  If
        !           135: using an i386 NetBSD kernel for the dom0, PAE is required (PAE
        !           136: versions are built by default).  While i386 dom0 works fine, amd64 is
        !           137: recommended as more normal.
        !           138: 
        !           139: Xen 4.2 is the last version to support i386 as a host.  TODO: Clarify
        !           140: if this is about the CPU having to be amd64, or about the dom0 kernel
        !           141: having to be amd64.
        !           142: 
        !           143: One can then run i386 domUs and amd64 domUs, in any combination.  If
        !           144: running an i386 NetBSD kernel as a domU, the PAE version is required.
        !           145: (Note that emacs (at least) fails if run on i386 with PAE when built
        !           146: without, and vice versa, presumably due to bugs in the undump code.)
1.18      gdt       147: 
1.15      gdt       148: Recommendation
                    149: --------------
                    150: 
1.18      gdt       151: Therefore, this HOWTO recommends running xenkernel42 (and xentools42),
1.19      gdt       152: xl, the NetBSD 6 stable branch, and to use amd64 as the dom0.  Either
                    153: the i386 or amd64 of NetBSD may be used as domUs.
1.15      gdt       154: 
                    155: NetBSD as a dom0
                    156: ================
                    157: 
                    158: NetBSD can be used as a dom0 and works very well.  The following
                    159: sections address installation, updating NetBSD, and updating Xen.
1.19      gdt       160: Note that it doesn't make sense to talk about installing a dom0 OS
                    161: without also installing Xen itself.  We first address installing
                    162: NetBSD, which is not yet a dom0, and then adding Xen, pivoting the
                    163: NetBSD install to a dom0 install by just changing the kernel and boot
                    164: configuration.
1.15      gdt       165: 
                    166: Styles of dom0 operation
                    167: ------------------------
                    168: 
                    169: There are two basic ways to use Xen.  The traditional method is for
                    170: the dom0 to do absolutely nothing other than providing support to some
                    171: number of domUs.  Such a system was probably installed for the sole
                    172: purpose of hosting domUs, and sits in a server room on a UPS.
                    173: 
                    174: The other way is to put Xen under a normal-usage computer, so that the
                    175: dom0 is what the computer would have been without Xen, perhaps a
                    176: desktop or laptop.  Then, one can run domUs at will.  Purists will
                    177: deride this as less secure than the previous approach, and for a
                    178: computer whose purpose is to run domUs, they are right.  But Xen and a
                    179: dom0 (without domUs) is not meaingfully less secure than the same
                    180: things running without Xen.  One can boot Xen or boot regular NetBSD
                    181: alternately with little problems, simply refraining from starting the
                    182: Xen daemons when not running Xen.
                    183: 
                    184: Note that NetBSD as dom0 does not support multiple CPUs.  This will
                    185: limit the performance of the Xen/dom0 workstation approach.
                    186: 
1.19      gdt       187: Installation of NetBSD
                    188: ----------------------
1.13      gdt       189: 
1.19      gdt       190: First,
1.27      jnemeth   191: [install NetBSD/amd64](/guide/inst/)
1.19      gdt       192: just as you would if you were not using Xen.
                    193: However, the partitioning approach is very important.
                    194: 
                    195: If you want to use RAIDframe for the dom0, there are no special issues
                    196: for Xen.  Typically one provides RAID storage for the dom0, and the
1.22      gdt       197: domU systems are unaware of RAID.  The 2nd-stage loader bootxx_* skips
                    198: over a RAID1 header to find /boot from a filesystem within a RAID
                    199: partition; this is no different when booting Xen.
1.19      gdt       200: 
                    201: There are 4 styles of providing backing storage for the virtual disks
                    202: used by domUs: raw partitions, LVM, file-backed vnd(4), and SAN,
                    203: 
                    204: With raw partitions, one has a disklabel (or gpt) partition sized for
                    205: each virtual disk to be used by the domU.  (If you are able to predict
                    206: how domU usage will evolve, please add an explanation to the HOWTO.
                    207: Seriously, needs tend to change over time.)
                    208: 
1.27      jnemeth   209: One can use [lvm(8)](/guide/lvm/) to create logical devices to use
                    210: for domU disks.  This is almost as efficient as raw disk partitions
                    211: and more flexible.  Hence raw disk partitions should typically not
                    212: be used.
1.19      gdt       213: 
                    214: One can use files in the dom0 filesystem, typically created by dd'ing
                    215: /dev/zero to create a specific size.  This is somewhat less efficient,
                    216: but very convenient, as one can cp the files for backup, or move them
                    217: between dom0 hosts.
                    218: 
                    219: Finally, in theory one can place the files backing the domU disks in a
                    220: SAN.  (This is an invitation for someone who has done this to add a
                    221: HOWTO page.)
1.1       mspo      222: 
1.19      gdt       223: Installation of Xen
                    224: -------------------
1.1       mspo      225: 
1.20      gdt       226: In the dom0, install sysutils/xenkernel42 and sysutils/xentools42 from
                    227: pkgsrc (or another matching pair).
                    228: See [the pkgsrc
                    229: documentation](http://www.NetBSD.org/docs/pkgsrc/) for help with pkgsrc.
                    230: 
                    231: For Xen 3.1, support for HVM guests is in sysutils/xentool3-hvm.  More
                    232: recent versions have HVM support integrated in the main xentools
                    233: package.  It is entirely reasonable to run only PV guests.
                    234: 
                    235: Next you need to install the selected Xen kernel itself, which is
                    236: installed by pkgsrc as "/usr/pkg/xen*-kernel/xen.gz".  Copy it to /.
                    237: For debugging, one may copy xen-debug.gz; this is conceptually similar
                    238: to DIAGNOSTIC and DEBUG in NetBSD.  xen-debug.gz is basically only
                    239: useful with a serial console.  Then, place a NetBSD XEN3_DOM0 kernel
                    240: in /, copied from releasedir/amd64/binary/kernel/netbsd-XEN3_DOM0.gz
                    241: of a NetBSD build.  Both xen and NetBSD may be left compressed.  (If
                    242: using i386, use releasedir/i386/binary/kernel/netbsd-XEN3PAE_DOM0.gz.)
                    243: 
                    244: In a dom0 kernel, kernfs is mandatory for xend to comunicate with the
                    245: kernel, so ensure that /kern is in fstab.
                    246: 
                    247: Because you already installed NetBSD, you have a working boot setup
                    248: with an MBR bootblock, either bootxx_ffsv1 or bootxx_ffsv2 at the
                    249: beginning of your root filesystem, /boot present, and likely
                    250: /boot.cfg.  (If not, fix before continuing!)
                    251: 
                    252: See boot.cfg(5) for an example.  The basic line is
                    253: 
                    254: "menu=Xen:load /netbsd-XEN3_DOM0.gz console=pc;multiboot /xen.gz dom0_mem=256M"
                    255: 
                    256: which specifies that the dom0 should have 256M, leaving the rest to be
                    257: allocated for domUs.
                    258: 
                    259: As with non-Xen systems, you should have a line to boot /netbsd (a
                    260: kernel that works without Xen) and fallback versions of the non-Xen
                    261: kernel, Xen, and the dom0 kernel.
1.1       mspo      262: 
1.28      gdt       263: The [HowTo on Installing into
                    264: RAID-1](http://mail-index.NetBSD.org/port-xen/2006/03/01/0010.html)
                    265: explains how to set up booting a dom0 with Xen using grub with
                    266: NetBSD's RAIDframe.  (This is obsolete with the use of NetBSD's native
                    267: boot.)
                    268: 
1.21      gdt       269: Configuring Xen
                    270: ---------------
                    271: 
                    272: Now, you have a system that will boot Xen and the dom0 kernel, and
                    273: just run the dom0 kernel.  There will be no domUs, and none can be
                    274: started because you still have to configure the dom0 tools.
                    275: 
                    276: For 3.3 (and probably 3.1), add to rc.conf (but note that you should
                    277: have installed 4.2):
                    278:   xend=YES
                    279:   xenbackendd=YES
                    280: 
                    281: For 4.1 and 4.2, add to rc.conf:
                    282:   xend=YES
                    283:   xencommons=YES
                    284: 
1.27      jnemeth   285: Note that xend is for supporting "xm", and should only be used if
                    286: you plan on using "xm".  Do NOT enable xend if you plan on using
                    287: "xl" as it will cause problems.
                    288: 
1.15      gdt       289: Updating NetBSD in a dom0
                    290: -------------------------
                    291: 
                    292: This is just like updating NetBSD on bare hardware, assuming the new
                    293: version supports the version of Xen you are running.  Generally, one
                    294: replaces the kernel and reboots, and then overlays userland binaries
                    295: and adjusts /etc.
                    296: 
                    297: Note that one must update both the non-Xen kernel typically used for
                    298: rescue purposes and the DOM0 kernel used with Xen.
                    299: 
1.22      gdt       300: To convert from grub to /boot, install an mbr bootblock with fdisk,
                    301: bootxx_ with installboot, /boot and /boot.cfg.  This really should be
                    302: no different than completely reinstalling boot blocks on a non-Xen
                    303: system.
                    304: 
1.15      gdt       305: Updating Xen versions
                    306: ---------------------
                    307: 
1.21      gdt       308: Updating Xen is conceptually not difficult, but can run into all the
                    309: issues found when installing Xen.  Assuming migration from 4.1 to 4.2,
                    310: remove the xenkernel41 and xentools41 packages and install the
                    311: xenkernel42 and xentools42 packages.  Copy the 4.2 xen.gz to /.
                    312: 
                    313: Ensure that the contents of /etc/rc.d/xen* are correct.  Enable the
                    314: correct set of daemons.  Ensure that the domU config files are valid
                    315: for the new version.
1.15      gdt       316: 
1.28      gdt       317: 
                    318: Unprivileged domains (domU)
                    319: ===========================
                    320: 
                    321: This section describes general concepts about domUs.  It does not
                    322: address specific domU operating systems or how to install them.
                    323: 
                    324: Provided Resources for PV domains
                    325: ---------------------------------
                    326: 
                    327: TODO: Explain that domUs get cpu, memory, disk and network.
                    328: Explain that randomness can be an issue.
                    329: 
                    330: Virtual disks
                    331: -------------
                    332: 
                    333: TODO: Explain how to set up files for vnd and that one should write all zeros to preallocate.
                    334: TODO: Explain in what NetBSD versions sparse vnd files do and don't work.
                    335: 
                    336: Virtual Networking
                    337: ------------------
                    338: 
                    339: TODO: explain xvif concept, and that it's general.
                    340: 
                    341: There are two normal styles: bridging and NAT.
                    342: 
                    343: With bridging, the domU perceives itself to be on the same network as
                    344: the dom0.  For server virtualization, this is usually best.
                    345: 
                    346: With NAT, the domU perceives itself to be behind a NAT running on the
                    347: dom0.  This is often appropriate when running Xen on a workstation.
                    348: 
                    349: One can construct arbitrary other configurations, but there is no
                    350: script support.
                    351: 
                    352: Config files
                    353: ------------
                    354: 
                    355: TODO: give example config files.   Use both lvm and vnd.
                    356: 
                    357: TODO: explain the mess with 3 arguments for disks and how to cope (0x1).
                    358: 
                    359: Starting domains
                    360: ----------------
                    361: 
                    362: TODO: Explain "xm start" and "xl start".  Explain rc.d/xendomains.
                    363: 
                    364: TODO: Explain why 4.1 rc.d/xendomains has xl, when one should use xm
                    365: on 4.1.
                    366: 
                    367: Creating specific unprivileged domains (domU)
                    368: =============================================
1.14      gdt       369: 
                    370: Creating domUs is almost entirely independent of operating system.  We
                    371: first explain NetBSD, and then differences for Linux and Solaris.
                    372: 
                    373: Creating an unprivileged NetBSD domain (domU)
                    374: ---------------------------------------------
1.1       mspo      375: 
                    376: Once you have *domain0* running, you need to start the xen tool daemon
1.5       mspo      377: (`/usr/pkg/share/examples/rc.d/xend start`) and the xen backend daemon
                    378: (`/usr/pkg/share/examples/rc.d/xenbackendd start` for Xen3\*,
                    379: `/usr/pkg/share/examples/rc.d/xencommons start` for Xen4.\*). Make sure
                    380: that `/dev/xencons` and `/dev/xenevt` exist before starting `xend`. You
                    381: can create them with this command:
1.1       mspo      382: 
1.3       mspo      383:     # cd /dev && sh MAKEDEV xen
1.1       mspo      384: 
1.5       mspo      385: xend will write logs to `/var/log/xend.log` and
                    386: `/var/log/xend-debug.log`. You can then control xen with the xm tool.
                    387: 'xm list' will show something like:
1.1       mspo      388: 
1.3       mspo      389:     # xm list
                    390:     Name              Id  Mem(MB)  CPU  State  Time(s)  Console
                    391:     Domain-0           0       64    0  r----     58.1
1.1       mspo      392: 
                    393: 'xm create' allows you to create a new domain. It uses a config file in
                    394: PKG\_SYSCONFDIR for its parameters. By default, this file will be in
1.5       mspo      395: `/usr/pkg/etc/xen/`. On creation, a kernel has to be specified, which
                    396: will be executed in the new domain (this kernel is in the *domain0* file
                    397: system, not on the new domain virtual disk; but please note, you should
                    398: install the same kernel into *domainU* as `/netbsd` in order to make
1.27      jnemeth   399: your system tools, like savecore(8), work). A suitable kernel is
1.5       mspo      400: provided as part of the i386 and amd64 binary sets: XEN3\_DOMU.
1.1       mspo      401: 
                    402: Here is an /usr/pkg/etc/xen/nbsd example config file:
                    403: 
1.3       mspo      404:     #  -*- mode: python; -*-
                    405:     #============================================================================
                    406:     # Python defaults setup for 'xm create'.
                    407:     # Edit this file to reflect the configuration of your system.
                    408:     #============================================================================
1.5       mspo      409: 
1.3       mspo      410:     #----------------------------------------------------------------------------
                    411:     # Kernel image file. This kernel will be loaded in the new domain.
                    412:     kernel = "/home/bouyer/netbsd-XEN3_DOMU"
                    413:     #kernel = "/home/bouyer/netbsd-INSTALL_XEN3_DOMU"
1.5       mspo      414: 
1.3       mspo      415:     # Memory allocation (in megabytes) for the new domain.
                    416:     memory = 128
1.5       mspo      417: 
1.3       mspo      418:     # A handy name for your new domain. This will appear in 'xm list',
                    419:     # and you can use this as parameters for xm in place of the domain
                    420:     # number. All domains must have different names.
                    421:     #
                    422:     name = "nbsd"
1.5       mspo      423: 
1.3       mspo      424:     # The number of virtual CPUs this domain has.
                    425:     #
                    426:     vcpus = 1
1.5       mspo      427: 
1.3       mspo      428:     #----------------------------------------------------------------------------
                    429:     # Define network interfaces for the new domain.
1.5       mspo      430: 
1.3       mspo      431:     # Number of network interfaces (must be at least 1). Default is 1.
                    432:     nics = 1
1.5       mspo      433: 
1.3       mspo      434:     # Define MAC and/or bridge for the network interfaces.
                    435:     #
                    436:     # The MAC address specified in ``mac'' is the one used for the interface
                    437:     # in the new domain. The interface in domain0 will use this address XOR'd
                    438:     # with 00:00:00:01:00:00 (i.e. aa:00:00:51:02:f0 in our example). Random
                    439:     # MACs are assigned if not given.
                    440:     #
                    441:     # ``bridge'' is a required parameter, which will be passed to the
                    442:     # vif-script called by xend(8) when a new domain is created to configure
                    443:     # the new xvif interface in domain0.
                    444:     #
                    445:     # In this example, the xvif is added to bridge0, which should have been
                    446:     # set up prior to the new domain being created -- either in the
                    447:     # ``network'' script or using a /etc/ifconfig.bridge0 file.
                    448:     #
                    449:     vif = [ 'mac=aa:00:00:50:02:f0, bridge=bridge0' ]
1.5       mspo      450: 
1.3       mspo      451:     #----------------------------------------------------------------------------
                    452:     # Define the disk devices you want the domain to have access to, and
                    453:     # what you want them accessible as.
                    454:     #
                    455:     # Each disk entry is of the form:
                    456:     #
1.5       mspo      457:     #   phy:DEV,VDEV,MODE
1.3       mspo      458:     #
                    459:     # where DEV is the device, VDEV is the device name the domain will see,
                    460:     # and MODE is r for read-only, w for read-write.  You can also create
                    461:     # file-backed domains using disk entries of the form:
                    462:     #
1.5       mspo      463:     #   file:PATH,VDEV,MODE
1.3       mspo      464:     #
                    465:     # where PATH is the path to the file used as the virtual disk, and VDEV
                    466:     # and MODE have the same meaning as for ``phy'' devices.
                    467:     #
                    468:     # VDEV doesn't really matter for a NetBSD guest OS (it's just used as an index),
                    469:     # but it does for Linux.
                    470:     # Worse, the device has to exist in /dev/ of domain0, because xm will
                    471:     # try to stat() it. This means that in order to load a Linux guest OS
                    472:     # from a NetBSD domain0, you'll have to create /dev/hda1, /dev/hda2, ...
                    473:     # on domain0, with the major/minor from Linux :(
                    474:     # Alternatively it's possible to specify the device number in hex,
                    475:     # e.g. 0x301 for /dev/hda1, 0x302 for /dev/hda2, etc ...
1.5       mspo      476: 
1.3       mspo      477:     disk = [ 'phy:/dev/wd0e,0x1,w' ]
                    478:     #disk = [ 'file:/var/xen/nbsd-disk,0x01,w' ]
                    479:     #disk = [ 'file:/var/xen/nbsd-disk,0x301,w' ]
1.5       mspo      480: 
1.3       mspo      481:     #----------------------------------------------------------------------------
                    482:     # Set the kernel command line for the new domain.
1.5       mspo      483: 
1.3       mspo      484:     # Set root device. This one does matter for NetBSD
                    485:     root = "xbd0"
                    486:     # extra parameters passed to the kernel
                    487:     # this is where you can set boot flags like -s, -a, etc ...
                    488:     #extra = ""
1.5       mspo      489: 
1.3       mspo      490:     #----------------------------------------------------------------------------
                    491:     # Set according to whether you want the domain restarted when it exits.
                    492:     # The default is False.
                    493:     #autorestart = True
1.5       mspo      494: 
1.3       mspo      495:     # end of nbsd config file ====================================================
1.1       mspo      496: 
                    497: When a new domain is created, xen calls the
1.5       mspo      498: `/usr/pkg/etc/xen/vif-bridge` script for each virtual network interface
                    499: created in *domain0*. This can be used to automatically configure the
                    500: xvif?.? interfaces in *domain0*. In our example, these will be bridged
                    501: with the bridge0 device in *domain0*, but the bridge has to exist first.
                    502: To do this, create the file `/etc/ifconfig.bridge0` and make it look
                    503: like this:
1.1       mspo      504: 
1.3       mspo      505:     create
                    506:     !brconfig $int add ex0 up
1.1       mspo      507: 
1.5       mspo      508: (replace `ex0` with the name of your physical interface). Then bridge0
1.27      jnemeth   509: will be created on boot. See the bridge(4) man page for details.
1.1       mspo      510: 
1.5       mspo      511: So, here is a suitable `/usr/pkg/etc/xen/vif-bridge` for xvif?.? (a
                    512: working vif-bridge is also provided with xentools20) configuring:
1.1       mspo      513: 
1.5       mspo      514:     #!/bin/sh
1.3       mspo      515:     #============================================================================
1.29    ! gdt       516:     # $NetBSD: howto.mdwn,v 1.28 2014/12/24 14:35:23 gdt Exp $
1.3       mspo      517:     #
                    518:     # /usr/pkg/etc/xen/vif-bridge
                    519:     #
                    520:     # Script for configuring a vif in bridged mode with a dom0 interface.
                    521:     # The xend(8) daemon calls a vif script when bringing a vif up or down.
                    522:     # The script name to use is defined in /usr/pkg/etc/xen/xend-config.sxp
                    523:     # in the ``vif-script'' field.
                    524:     #
                    525:     # Usage: vif-bridge up|down [var=value ...]
                    526:     #
                    527:     # Actions:
1.5       mspo      528:     #    up     Adds the vif interface to the bridge.
                    529:     #    down   Removes the vif interface from the bridge.
1.3       mspo      530:     #
                    531:     # Variables:
1.5       mspo      532:     #    domain name of the domain the interface is on (required).
                    533:     #    vifq   vif interface name (required).
                    534:     #    mac    vif MAC address (required).
                    535:     #    bridge bridge to add the vif to (required).
1.3       mspo      536:     #
                    537:     # Example invocation:
                    538:     #
                    539:     # vif-bridge up domain=VM1 vif=xvif1.0 mac="ee:14:01:d0:ec:af" bridge=bridge0
                    540:     #
                    541:     #============================================================================
1.5       mspo      542: 
1.3       mspo      543:     # Exit if anything goes wrong
                    544:     set -e
1.5       mspo      545: 
1.3       mspo      546:     echo "vif-bridge $*"
1.5       mspo      547: 
1.3       mspo      548:     # Operation name.
                    549:     OP=$1; shift
1.5       mspo      550: 
1.3       mspo      551:     # Pull variables in args into environment
                    552:     for arg ; do export "${arg}" ; done
1.5       mspo      553: 
1.3       mspo      554:     # Required parameters. Fail if not set.
                    555:     domain=${domain:?}
                    556:     vif=${vif:?}
                    557:     mac=${mac:?}
                    558:     bridge=${bridge:?}
1.5       mspo      559: 
1.3       mspo      560:     # Optional parameters. Set defaults.
                    561:     ip=${ip:-''}   # default to null (do nothing)
1.5       mspo      562: 
1.3       mspo      563:     # Are we going up or down?
                    564:     case $OP in
1.5       mspo      565:     up) brcmd='add' ;;
1.3       mspo      566:     down)   brcmd='delete' ;;
                    567:     *)
1.5       mspo      568:         echo 'Invalid command: ' $OP
                    569:         echo 'Valid commands are: up, down'
                    570:         exit 1
                    571:         ;;
1.3       mspo      572:     esac
1.5       mspo      573: 
1.3       mspo      574:     # Don't do anything if the bridge is "null".
                    575:     if [ "${bridge}" = "null" ] ; then
1.5       mspo      576:         exit
1.3       mspo      577:     fi
1.5       mspo      578: 
1.3       mspo      579:     # Don't do anything if the bridge doesn't exist.
                    580:     if ! ifconfig -l | grep "${bridge}" >/dev/null; then
1.5       mspo      581:         exit
1.3       mspo      582:     fi
1.5       mspo      583: 
1.3       mspo      584:     # Add/remove vif to/from bridge.
                    585:     ifconfig x${vif} $OP
                    586:     brconfig ${bridge} ${brcmd} x${vif}
1.1       mspo      587: 
                    588: Now, running
                    589: 
1.3       mspo      590:     xm create -c /usr/pkg/etc/xen/nbsd
1.1       mspo      591: 
1.5       mspo      592: should create a domain and load a NetBSD kernel in it. (Note: `-c`
                    593: causes xm to connect to the domain's console once created.) The kernel
                    594: will try to find its root file system on xbd0 (i.e., wd0e) which hasn't
                    595: been created yet. wd0e will be seen as a disk device in the new domain,
                    596: so it will be 'sub-partitioned'. We could attach a ccd to wd0e in
                    597: *domain0* and partition it, newfs and extract the NetBSD/i386 or amd64
                    598: tarballs there, but there's an easier way: load the
                    599: `netbsd-INSTALL_XEN3_DOMU` kernel provided in the NetBSD binary sets.
                    600: Like other install kernels, it contains a ramdisk with sysinst, so you
                    601: can install NetBSD using sysinst on your new domain.
1.1       mspo      602: 
                    603: If you want to install NetBSD/Xen with a CDROM image, the following line
1.5       mspo      604: should be used in the `/usr/pkg/etc/xen/nbsd` file:
1.1       mspo      605: 
1.3       mspo      606:     disk = [ 'phy:/dev/wd0e,0x1,w', 'phy:/dev/cd0a,0x2,r' ]
1.1       mspo      607: 
                    608: After booting the domain, the option to install via CDROM may be
1.5       mspo      609: selected. The CDROM device should be changed to `xbd1d`.
1.1       mspo      610: 
1.5       mspo      611: Once done installing, `halt -p` the new domain (don't reboot or halt, it
                    612: would reload the INSTALL\_XEN3\_DOMU kernel even if you changed the
1.1       mspo      613: config file), switch the config file back to the XEN3\_DOMU kernel, and
1.5       mspo      614: start the new domain again. Now it should be able to use `root on xbd0a`
                    615: and you should have a second, functional NetBSD system on your xen
                    616: installation.
1.1       mspo      617: 
                    618: When the new domain is booting you'll see some warnings about *wscons*
                    619: and the pseudo-terminals. These can be fixed by editing the files
1.5       mspo      620: `/etc/ttys` and `/etc/wscons.conf`. You must disable all terminals in
                    621: `/etc/ttys`, except *console*, like this:
1.1       mspo      622: 
1.3       mspo      623:     console "/usr/libexec/getty Pc"         vt100   on secure
                    624:     ttyE0   "/usr/libexec/getty Pc"         vt220   off secure
                    625:     ttyE1   "/usr/libexec/getty Pc"         vt220   off secure
                    626:     ttyE2   "/usr/libexec/getty Pc"         vt220   off secure
                    627:     ttyE3   "/usr/libexec/getty Pc"         vt220   off secure
1.1       mspo      628: 
1.5       mspo      629: Finally, all screens must be commented out from `/etc/wscons.conf`.
1.1       mspo      630: 
                    631: It is also desirable to add
                    632: 
1.3       mspo      633:     powerd=YES
1.1       mspo      634: 
1.5       mspo      635: in rc.conf. This way, the domain will be properly shut down if
                    636: `xm shutdown -R` or `xm shutdown -H` is used on the domain0.
1.1       mspo      637: 
                    638: Your domain should be now ready to work, enjoy.
                    639: 
1.14      gdt       640: Creating an unprivileged Linux domain (domU)
1.5       mspo      641: --------------------------------------------
1.1       mspo      642: 
                    643: Creating unprivileged Linux domains isn't much different from
                    644: unprivileged NetBSD domains, but there are some details to know.
                    645: 
                    646: First, the second parameter passed to the disk declaration (the '0x1' in
                    647: the example below)
                    648: 
1.3       mspo      649:     disk = [ 'phy:/dev/wd0e,0x1,w' ]
1.1       mspo      650: 
                    651: does matter to Linux. It wants a Linux device number here (e.g. 0x300
                    652: for hda). Linux builds device numbers as: (major \<\< 8 + minor). So,
                    653: hda1 which has major 3 and minor 1 on a Linux system will have device
                    654: number 0x301. Alternatively, devices names can be used (hda, hdb, ...)
                    655: as xentools has a table to map these names to devices numbers. To export
                    656: a partition to a Linux guest we can use:
                    657: 
1.3       mspo      658:     disk = [ 'phy:/dev/wd0e,0x300,w' ]
                    659:     root = "/dev/hda1 ro"
1.1       mspo      660: 
                    661: and it will appear as /dev/hda on the Linux system, and be used as root
                    662: partition.
                    663: 
                    664: To install the Linux system on the partition to be exported to the guest
                    665: domain, the following method can be used: install sysutils/e2fsprogs
                    666: from pkgsrc. Use mke2fs to format the partition that will be the root
                    667: partition of your Linux domain, and mount it. Then copy the files from a
1.5       mspo      668: working Linux system, make adjustments in `/etc` (fstab, network
                    669: config). It should also be possible to extract binary packages such as
                    670: .rpm or .deb directly to the mounted partition using the appropriate
                    671: tool, possibly running under NetBSD's Linux emulation. Once the
                    672: filesystem has been populated, umount it. If desirable, the filesystem
                    673: can be converted to ext3 using tune2fs -j. It should now be possible to
                    674: boot the Linux guest domain, using one of the vmlinuz-\*-xenU kernels
                    675: available in the Xen binary distribution.
1.1       mspo      676: 
                    677: To get the linux console right, you need to add:
                    678: 
1.3       mspo      679:     extra = "xencons=tty1"
1.1       mspo      680: 
                    681: to your configuration since not all linux distributions auto-attach a
                    682: tty to the xen console.
                    683: 
1.14      gdt       684: Creating an unprivileged Solaris domain (domU)
1.5       mspo      685: ----------------------------------------------
1.1       mspo      686: 
                    687: Download an Opensolaris [release](http://opensolaris.org/os/downloads/)
                    688: or [development snapshot](http://genunix.org/) DVD image. Attach the DVD
1.5       mspo      689: image to a MAN.VND.4 device. Copy the kernel and ramdisk filesystem
                    690: image to your dom0 filesystem.
1.1       mspo      691: 
1.3       mspo      692:     dom0# mkdir /root/solaris
                    693:     dom0# vnconfig vnd0 osol-1002-124-x86.iso
                    694:     dom0# mount /dev/vnd0a /mnt
1.5       mspo      695: 
1.3       mspo      696:     ## for a 64-bit guest
                    697:     dom0# cp /mnt/boot/amd64/x86.microroot /root/solaris
                    698:     dom0# cp /mnt/platform/i86xpv/kernel/amd64/unix /root/solaris
1.5       mspo      699: 
1.3       mspo      700:     ## for a 32-bit guest
                    701:     dom0# cp /mnt/boot/x86.microroot /root/solaris
                    702:     dom0# cp /mnt/platform/i86xpv/kernel/unix /root/solaris
1.5       mspo      703: 
1.3       mspo      704:     dom0# umount /mnt
1.5       mspo      705:           
                    706: 
                    707: Keep the MAN.VND.4 configured. For some reason the boot process stalls
                    708: unless the DVD image is attached to the guest as a "phy" device. Create
                    709: an initial configuration file with the following contents. Substitute
                    710: */dev/wd0k* with an empty partition at least 8 GB large.
1.1       mspo      711: 
1.4       mspo      712:     memory = 640
                    713:     name = 'solaris'
                    714:     disk = [ 'phy:/dev/wd0k,0,w' ]
                    715:     disk += [ 'phy:/dev/vnd0d,6:cdrom,r' ]
                    716:     vif = [ 'bridge=bridge0' ]
                    717:     kernel = '/root/solaris/unix'
                    718:     ramdisk = '/root/solaris/x86.microroot'
                    719:     # for a 64-bit guest
                    720:     extra = '/platform/i86xpv/kernel/amd64/unix - nowin -B install_media=cdrom'
                    721:     # for a 32-bit guest
                    722:     #extra = '/platform/i86xpv/kernel/unix - nowin -B install_media=cdrom'
1.5       mspo      723:           
                    724: 
1.1       mspo      725: Start the guest.
                    726: 
1.4       mspo      727:     dom0# xm create -c solaris.cfg
                    728:     Started domain solaris
                    729:                           v3.3.2 chgset 'unavailable'
                    730:     SunOS Release 5.11 Version snv_124 64-bit
                    731:     Copyright 1983-2009 Sun Microsystems, Inc.  All rights reserved.
                    732:     Use is subject to license terms.
                    733:     Hostname: opensolaris
                    734:     Remounting root read/write
                    735:     Probing for device nodes ...
                    736:     WARNING: emlxs: ddi_modopen drv/fct failed: err 2
                    737:     Preparing live image for use
                    738:     Done mounting Live image
1.5       mspo      739:           
1.1       mspo      740: 
                    741: Make sure the network is configured. Note that it can take a minute for
                    742: the xnf0 interface to appear.
                    743: 
1.4       mspo      744:     opensolaris console login: jack
                    745:     Password: jack
                    746:     Sun Microsystems Inc.   SunOS 5.11      snv_124 November 2008
                    747:     jack@opensolaris:~$ pfexec sh
                    748:     sh-3.2# ifconfig -a
                    749:     sh-3.2# exit
1.5       mspo      750:           
1.1       mspo      751: 
                    752: Set a password for VNC and start the VNC server which provides the X11
                    753: display where the installation program runs.
                    754: 
1.4       mspo      755:     jack@opensolaris:~$ vncpasswd
                    756:     Password: solaris
                    757:     Verify: solaris
                    758:     jack@opensolaris:~$ cp .Xclients .vnc/xstartup
                    759:     jack@opensolaris:~$ vncserver :1
1.5       mspo      760:           
1.1       mspo      761: 
1.5       mspo      762: From a remote machine connect to the VNC server. Use `ifconfig xnf0` on
                    763: the guest to find the correct IP address to use.
1.1       mspo      764: 
1.4       mspo      765:     remote$ vncviewer 172.18.2.99:1
1.5       mspo      766:           
1.1       mspo      767: 
                    768: It is also possible to launch the installation on a remote X11 display.
                    769: 
1.4       mspo      770:     jack@opensolaris:~$ export DISPLAY=172.18.1.1:0
                    771:     jack@opensolaris:~$ pfexec gui-install
1.5       mspo      772:            
1.1       mspo      773: 
                    774: After the GUI installation is complete you will be asked to reboot.
                    775: Before that you need to determine the ZFS ID for the new boot filesystem
                    776: and update the configuration file accordingly. Return to the guest
                    777: console.
                    778: 
1.4       mspo      779:     jack@opensolaris:~$ pfexec zdb -vvv rpool | grep bootfs
                    780:                     bootfs = 43
                    781:     ^C
                    782:     jack@opensolaris:~$
1.5       mspo      783:            
1.1       mspo      784: 
                    785: The final configuration file should look like this. Note in particular
                    786: the last line.
                    787: 
1.4       mspo      788:     memory = 640
                    789:     name = 'solaris'
                    790:     disk = [ 'phy:/dev/wd0k,0,w' ]
                    791:     vif = [ 'bridge=bridge0' ]
                    792:     kernel = '/root/solaris/unix'
                    793:     ramdisk = '/root/solaris/x86.microroot'
                    794:     extra = '/platform/i86xpv/kernel/amd64/unix -B zfs-bootfs=rpool/43,bootpath="/xpvd/xdf@0:a"'
1.5       mspo      795:            
1.1       mspo      796: 
                    797: Restart the guest to verify it works correctly.
                    798: 
1.4       mspo      799:     dom0# xm destroy solaris
                    800:     dom0# xm create -c solaris.cfg
                    801:     Using config file "./solaris.cfg".
                    802:     v3.3.2 chgset 'unavailable'
                    803:     Started domain solaris
                    804:     SunOS Release 5.11 Version snv_124 64-bit
                    805:     Copyright 1983-2009 Sun Microsystems, Inc.  All rights reserved.
                    806:     Use is subject to license terms.
                    807:     WARNING: emlxs: ddi_modopen drv/fct failed: err 2
                    808:     Hostname: osol
                    809:     Configuring devices.
                    810:     Loading smf(5) service descriptions: 160/160
                    811:     svccfg import warnings. See /var/svc/log/system-manifest-import:default.log .
                    812:     Reading ZFS config: done.
                    813:     Mounting ZFS filesystems: (6/6)
                    814:     Creating new rsa public/private host key pair
                    815:     Creating new dsa public/private host key pair
1.5       mspo      816: 
1.4       mspo      817:     osol console login:
1.5       mspo      818:            
1.1       mspo      819: 
                    820: Using PCI devices in guest domains
1.14      gdt       821: ----------------------------------
1.1       mspo      822: 
                    823: The domain0 can give other domains access to selected PCI devices. This
                    824: can allow, for example, a non-privileged domain to have access to a
                    825: physical network interface or disk controller. However, keep in mind
                    826: that giving a domain access to a PCI device most likely will give the
                    827: domain read/write access to the whole physical memory, as PCs don't have
                    828: an IOMMU to restrict memory access to DMA-capable device. Also, it's not
                    829: possible to export ISA devices to non-domain0 domains (which means that
                    830: the primary VGA adapter can't be exported. A guest domain trying to
                    831: access the VGA registers will panic).
                    832: 
                    833: This functionality is only available in NetBSD-5.1 (and later) domain0
                    834: and domU. If the domain0 is NetBSD, it has to be running Xen 3.1, as
                    835: support has not been ported to later versions at this time.
                    836: 
                    837: For a PCI device to be exported to a domU, is has to be attached to the
1.5       mspo      838: `pciback` driver in domain0. Devices passed to the domain0 via the
                    839: pciback.hide boot parameter will attach to `pciback` instead of the
                    840: usual driver. The list of devices is specified as `(bus:dev.func)`,
                    841: where bus and dev are 2-digit hexadecimal numbers, and func a
                    842: single-digit number:
1.1       mspo      843: 
1.4       mspo      844:     pciback.hide=(00:0a.0)(00:06.0)
1.1       mspo      845: 
                    846: pciback devices should show up in the domain0's boot messages, and the
1.5       mspo      847: devices should be listed in the `/kern/xen/pci` directory.
1.1       mspo      848: 
1.5       mspo      849: PCI devices to be exported to a domU are listed in the `pci` array of
                    850: the domU's config file, with the format `'0000:bus:dev.func'`
1.1       mspo      851: 
1.4       mspo      852:     pci = [ '0000:00:06.0', '0000:00:0a.0' ]
1.1       mspo      853: 
1.5       mspo      854: In the domU an `xpci` device will show up, to which one or more pci
                    855: busses will attach. Then the PCI drivers will attach to PCI busses as
                    856: usual. Note that the default NetBSD DOMU kernels do not have `xpci` or
                    857: any PCI drivers built in by default; you have to build your own kernel
                    858: to use PCI devices in a domU. Here's a kernel config example:
1.1       mspo      859: 
1.4       mspo      860:     include         "arch/i386/conf/XEN3_DOMU"
                    861:     #include         "arch/i386/conf/XENU"           # in NetBSD 3.0
1.5       mspo      862: 
1.4       mspo      863:     # Add support for PCI busses to the XEN3_DOMU kernel
                    864:     xpci* at xenbus ?
                    865:     pci* at xpci ?
1.5       mspo      866: 
1.4       mspo      867:     # Now add PCI and related devices to be used by this domain
                    868:     # USB Controller and Devices
1.5       mspo      869: 
1.4       mspo      870:     # PCI USB controllers
                    871:     uhci*   at pci? dev ? function ?        # Universal Host Controller (Intel)
1.5       mspo      872: 
1.4       mspo      873:     # USB bus support
                    874:     usb*    at uhci?
1.5       mspo      875: 
1.4       mspo      876:     # USB Hubs
                    877:     uhub*   at usb?
                    878:     uhub*   at uhub? port ? configuration ? interface ?
1.5       mspo      879: 
1.4       mspo      880:     # USB Mass Storage
                    881:     umass*  at uhub? port ? configuration ? interface ?
                    882:     wd*     at umass?
                    883:     # SCSI controllers
                    884:     ahc*    at pci? dev ? function ?        # Adaptec [23]94x, aic78x0 SCSI
1.5       mspo      885: 
1.4       mspo      886:     # SCSI bus support (for both ahc and umass)
                    887:     scsibus* at scsi?
1.5       mspo      888: 
1.4       mspo      889:     # SCSI devices
                    890:     sd*     at scsibus? target ? lun ?      # SCSI disk drives
                    891:     cd*     at scsibus? target ? lun ?      # SCSI CD-ROM drives
1.1       mspo      892: 
                    893: 
1.28      gdt       894: NetBSD as a domU in a VPS
                    895: =========================
                    896: 
                    897: The bulk of the HOWTO is about using NetBSD as a dom0 on your own
                    898: hardware.  This section explains how to deal with Xen in a domU as a
                    899: virtual private server where you do not control or have access to the
                    900: dom0.
                    901: 
                    902: TODO: Perhaps reference panix, prmgr, amazon as interesting examples.
                    903: 
                    904: TODO: Somewhere, discuss pvgrub and py-grub to load the domU kernel
                    905: from the domU filesystem.

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