Annotation of wikisrc/ports/xen/howto.mdwn, revision 1.34
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),
1.30 gdt 152: xl, the NetBSD 6 stable branch, and to use an amd64 kernel as the
153: dom0. Either 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
1.31 gdt 274: started because you still have to configure the dom0 tools. The
275: daemons which should be run vary with Xen version and with whether one
276: is using xm or xl. Note that xend is for supporting "xm", and should
277: only be used if you plan on using "xm". Do NOT enable xend if you
278: plan on using "xl" as it will cause problems.
1.21 gdt 279:
1.31 gdt 280: TODO: Give 3.1 advice (or remove it from pkgsrc).
281:
282: For 3.3 (and thus xm), add to rc.conf (but note that you should have
283: installed 4.1 or 4.2):
284:
1.32 gdt 285: xend=YES
286: xenbackendd=YES
1.31 gdt 287:
1.33 gdt 288: For 4.1 (and thus xm; xl is believed not to work well), add to rc.conf:
1.31 gdt 289:
290: xend=YES
291: xencommons=YES
292:
293: TODO: Explain why if xm is preferred on 4.1, rc.d/xendomains has xl.
1.33 gdt 294: Or fix the package.
1.31 gdt 295:
1.33 gdt 296: For 4.2 with xm, add to rc.conf
297:
298: xend=YES
299: xencommons=YES
300:
301: For 4.2 with xl (preferred), add to rc.conf:
1.31 gdt 302:
303: TODO: explain if there is a xend replacement
304: xencommons=YES
305:
306: TODO: Recommend for/against xen-watchdog.
1.27 jnemeth 307:
1.33 gdt 308: After you have configured the daemons and rebooted, run the following
309: to inspect Xen's boot messages, available resources, and running
310: domains:
1.34 ! gdt 311:
1.33 gdt 312: xm dmesg
313: xm info
314: xm list
315:
1.15 gdt 316: Updating NetBSD in a dom0
317: -------------------------
318:
319: This is just like updating NetBSD on bare hardware, assuming the new
320: version supports the version of Xen you are running. Generally, one
321: replaces the kernel and reboots, and then overlays userland binaries
322: and adjusts /etc.
323:
324: Note that one must update both the non-Xen kernel typically used for
325: rescue purposes and the DOM0 kernel used with Xen.
326:
1.22 gdt 327: To convert from grub to /boot, install an mbr bootblock with fdisk,
328: bootxx_ with installboot, /boot and /boot.cfg. This really should be
329: no different than completely reinstalling boot blocks on a non-Xen
330: system.
331:
1.15 gdt 332: Updating Xen versions
333: ---------------------
334:
1.21 gdt 335: Updating Xen is conceptually not difficult, but can run into all the
336: issues found when installing Xen. Assuming migration from 4.1 to 4.2,
337: remove the xenkernel41 and xentools41 packages and install the
338: xenkernel42 and xentools42 packages. Copy the 4.2 xen.gz to /.
339:
340: Ensure that the contents of /etc/rc.d/xen* are correct. Enable the
341: correct set of daemons. Ensure that the domU config files are valid
342: for the new version.
1.15 gdt 343:
1.28 gdt 344:
345: Unprivileged domains (domU)
346: ===========================
347:
348: This section describes general concepts about domUs. It does not
1.33 gdt 349: address specific domU operating systems or how to install them. The
350: config files for domUs are typically in /usr/pkg/etc/xen, and are
351: typically named so that the file anme, domU name and the domU's host
352: name match.
353:
354: The domU is provided with cpu and memory by Xen, configured by the
355: dom0. The domU is provided with disk and network by the dom0,
356: mediated by Xen, and configured in the dom0.
357:
358: Entropy in domUs can be an issue; physical disks and network are on
359: the dom0. NetBSD's /dev/random system works, but is often challenged.
360:
361: CPU and memory
362: --------------
363:
364: A domain is provided with some number of vcpus, less than the
365: number of cpus seen by the hypervisor. For a dom0, this is controlled
366: by the boot argument "dom0_max_vcpus=1". For a domU, it is controlled
367: from the config file.
368:
369: A domain is provided with memory, In the straightforward case, the sum
370: of the the memory allocated to the dom0 and all domUs must be less
371: than the available memory.
372:
373: Xen also provides a "balloon" driver, which can be used to let domains
374: use more memory temporarily. TODO: Explain better, and explain how
375: well it works with NetBSD.
1.28 gdt 376:
377: Virtual disks
378: -------------
379:
1.33 gdt 380: With the file/vnd style, typically one creates a directory,
381: e.g. /u0/xen, on a disk large enough to hold virtual disks for all
382: domUs. Then, for each domU disk, one writes zeros to a file that then
383: serves to hold the virtual disk's bits; a suggested name is foo-xbd0
384: for the first virtual disk for the domU called foo. Writing zeros to
385: the file serves two purposes. One is that preallocating the contents
386: improves performance. The other is that vnd on sparse files has
387: failed to work. TODO: give working/notworking NetBSD versions for
388: sparse vnd. Note that the use of file/vnd for Xen is not really
389: different than creating a file-backed virtual disk for some other
390: purpose, except that xentools handles the vnconfig commands.
391:
392: With the lvm style, one creates logical devices. They are then used
393: similarly to vnds.
1.28 gdt 394:
395: Virtual Networking
396: ------------------
397:
398: TODO: explain xvif concept, and that it's general.
399:
400: There are two normal styles: bridging and NAT.
401:
402: With bridging, the domU perceives itself to be on the same network as
403: the dom0. For server virtualization, this is usually best.
404:
405: With NAT, the domU perceives itself to be behind a NAT running on the
406: dom0. This is often appropriate when running Xen on a workstation.
407:
408: One can construct arbitrary other configurations, but there is no
409: script support.
410:
1.33 gdt 411: Sizing domains
412: --------------
413:
414: Modern x86 hardware has vast amounts of resources. However, many
415: virtual servers can function just fine on far less. A system with
416: 256M of RAM and a 4G disk can be a reasonable choice. Note that it is
417: far easier to adjust virtual resources than physical ones. For
418: memory, it's just a config file edit and a reboot. For disk, one can
419: create a new file and vnconfig it (or lvm), and then dump/restore,
420: just like updating physical disks, but without having to be there and
421: without those pesky connectors.
422:
1.28 gdt 423: Config files
424: ------------
425:
426: TODO: give example config files. Use both lvm and vnd.
427:
428: TODO: explain the mess with 3 arguments for disks and how to cope (0x1).
429:
430: Starting domains
431: ----------------
432:
433: TODO: Explain "xm start" and "xl start". Explain rc.d/xendomains.
434:
435: TODO: Explain why 4.1 rc.d/xendomains has xl, when one should use xm
436: on 4.1.
437:
438: Creating specific unprivileged domains (domU)
439: =============================================
1.14 gdt 440:
441: Creating domUs is almost entirely independent of operating system. We
442: first explain NetBSD, and then differences for Linux and Solaris.
443:
444: Creating an unprivileged NetBSD domain (domU)
445: ---------------------------------------------
1.1 mspo 446:
447: Once you have *domain0* running, you need to start the xen tool daemon
1.5 mspo 448: (`/usr/pkg/share/examples/rc.d/xend start`) and the xen backend daemon
449: (`/usr/pkg/share/examples/rc.d/xenbackendd start` for Xen3\*,
450: `/usr/pkg/share/examples/rc.d/xencommons start` for Xen4.\*). Make sure
451: that `/dev/xencons` and `/dev/xenevt` exist before starting `xend`. You
452: can create them with this command:
1.1 mspo 453:
1.3 mspo 454: # cd /dev && sh MAKEDEV xen
1.1 mspo 455:
1.5 mspo 456: xend will write logs to `/var/log/xend.log` and
457: `/var/log/xend-debug.log`. You can then control xen with the xm tool.
458: 'xm list' will show something like:
1.1 mspo 459:
1.3 mspo 460: # xm list
461: Name Id Mem(MB) CPU State Time(s) Console
462: Domain-0 0 64 0 r---- 58.1
1.1 mspo 463:
464: 'xm create' allows you to create a new domain. It uses a config file in
465: PKG\_SYSCONFDIR for its parameters. By default, this file will be in
1.5 mspo 466: `/usr/pkg/etc/xen/`. On creation, a kernel has to be specified, which
467: will be executed in the new domain (this kernel is in the *domain0* file
468: system, not on the new domain virtual disk; but please note, you should
469: install the same kernel into *domainU* as `/netbsd` in order to make
1.27 jnemeth 470: your system tools, like savecore(8), work). A suitable kernel is
1.5 mspo 471: provided as part of the i386 and amd64 binary sets: XEN3\_DOMU.
1.1 mspo 472:
473: Here is an /usr/pkg/etc/xen/nbsd example config file:
474:
1.3 mspo 475: # -*- mode: python; -*-
476: #============================================================================
477: # Python defaults setup for 'xm create'.
478: # Edit this file to reflect the configuration of your system.
479: #============================================================================
1.5 mspo 480:
1.3 mspo 481: #----------------------------------------------------------------------------
482: # Kernel image file. This kernel will be loaded in the new domain.
483: kernel = "/home/bouyer/netbsd-XEN3_DOMU"
484: #kernel = "/home/bouyer/netbsd-INSTALL_XEN3_DOMU"
1.5 mspo 485:
1.3 mspo 486: # Memory allocation (in megabytes) for the new domain.
487: memory = 128
1.5 mspo 488:
1.3 mspo 489: # A handy name for your new domain. This will appear in 'xm list',
490: # and you can use this as parameters for xm in place of the domain
491: # number. All domains must have different names.
492: #
493: name = "nbsd"
1.5 mspo 494:
1.3 mspo 495: # The number of virtual CPUs this domain has.
496: #
497: vcpus = 1
1.5 mspo 498:
1.3 mspo 499: #----------------------------------------------------------------------------
500: # Define network interfaces for the new domain.
1.5 mspo 501:
1.3 mspo 502: # Number of network interfaces (must be at least 1). Default is 1.
503: nics = 1
1.5 mspo 504:
1.3 mspo 505: # Define MAC and/or bridge for the network interfaces.
506: #
507: # The MAC address specified in ``mac'' is the one used for the interface
508: # in the new domain. The interface in domain0 will use this address XOR'd
509: # with 00:00:00:01:00:00 (i.e. aa:00:00:51:02:f0 in our example). Random
510: # MACs are assigned if not given.
511: #
512: # ``bridge'' is a required parameter, which will be passed to the
513: # vif-script called by xend(8) when a new domain is created to configure
514: # the new xvif interface in domain0.
515: #
516: # In this example, the xvif is added to bridge0, which should have been
517: # set up prior to the new domain being created -- either in the
518: # ``network'' script or using a /etc/ifconfig.bridge0 file.
519: #
520: vif = [ 'mac=aa:00:00:50:02:f0, bridge=bridge0' ]
1.5 mspo 521:
1.3 mspo 522: #----------------------------------------------------------------------------
523: # Define the disk devices you want the domain to have access to, and
524: # what you want them accessible as.
525: #
526: # Each disk entry is of the form:
527: #
1.5 mspo 528: # phy:DEV,VDEV,MODE
1.3 mspo 529: #
530: # where DEV is the device, VDEV is the device name the domain will see,
531: # and MODE is r for read-only, w for read-write. You can also create
532: # file-backed domains using disk entries of the form:
533: #
1.5 mspo 534: # file:PATH,VDEV,MODE
1.3 mspo 535: #
536: # where PATH is the path to the file used as the virtual disk, and VDEV
537: # and MODE have the same meaning as for ``phy'' devices.
538: #
539: # VDEV doesn't really matter for a NetBSD guest OS (it's just used as an index),
540: # but it does for Linux.
541: # Worse, the device has to exist in /dev/ of domain0, because xm will
542: # try to stat() it. This means that in order to load a Linux guest OS
543: # from a NetBSD domain0, you'll have to create /dev/hda1, /dev/hda2, ...
544: # on domain0, with the major/minor from Linux :(
545: # Alternatively it's possible to specify the device number in hex,
546: # e.g. 0x301 for /dev/hda1, 0x302 for /dev/hda2, etc ...
1.5 mspo 547:
1.3 mspo 548: disk = [ 'phy:/dev/wd0e,0x1,w' ]
549: #disk = [ 'file:/var/xen/nbsd-disk,0x01,w' ]
550: #disk = [ 'file:/var/xen/nbsd-disk,0x301,w' ]
1.5 mspo 551:
1.3 mspo 552: #----------------------------------------------------------------------------
553: # Set the kernel command line for the new domain.
1.5 mspo 554:
1.3 mspo 555: # Set root device. This one does matter for NetBSD
556: root = "xbd0"
557: # extra parameters passed to the kernel
558: # this is where you can set boot flags like -s, -a, etc ...
559: #extra = ""
1.5 mspo 560:
1.3 mspo 561: #----------------------------------------------------------------------------
562: # Set according to whether you want the domain restarted when it exits.
563: # The default is False.
564: #autorestart = True
1.5 mspo 565:
1.3 mspo 566: # end of nbsd config file ====================================================
1.1 mspo 567:
568: When a new domain is created, xen calls the
1.5 mspo 569: `/usr/pkg/etc/xen/vif-bridge` script for each virtual network interface
570: created in *domain0*. This can be used to automatically configure the
571: xvif?.? interfaces in *domain0*. In our example, these will be bridged
572: with the bridge0 device in *domain0*, but the bridge has to exist first.
573: To do this, create the file `/etc/ifconfig.bridge0` and make it look
574: like this:
1.1 mspo 575:
1.3 mspo 576: create
577: !brconfig $int add ex0 up
1.1 mspo 578:
1.5 mspo 579: (replace `ex0` with the name of your physical interface). Then bridge0
1.27 jnemeth 580: will be created on boot. See the bridge(4) man page for details.
1.1 mspo 581:
1.5 mspo 582: So, here is a suitable `/usr/pkg/etc/xen/vif-bridge` for xvif?.? (a
583: working vif-bridge is also provided with xentools20) configuring:
1.1 mspo 584:
1.5 mspo 585: #!/bin/sh
1.3 mspo 586: #============================================================================
1.34 ! gdt 587: # $NetBSD: howto.mdwn,v 1.33 2014/12/24 15:54:50 gdt Exp $
1.3 mspo 588: #
589: # /usr/pkg/etc/xen/vif-bridge
590: #
591: # Script for configuring a vif in bridged mode with a dom0 interface.
592: # The xend(8) daemon calls a vif script when bringing a vif up or down.
593: # The script name to use is defined in /usr/pkg/etc/xen/xend-config.sxp
594: # in the ``vif-script'' field.
595: #
596: # Usage: vif-bridge up|down [var=value ...]
597: #
598: # Actions:
1.5 mspo 599: # up Adds the vif interface to the bridge.
600: # down Removes the vif interface from the bridge.
1.3 mspo 601: #
602: # Variables:
1.5 mspo 603: # domain name of the domain the interface is on (required).
604: # vifq vif interface name (required).
605: # mac vif MAC address (required).
606: # bridge bridge to add the vif to (required).
1.3 mspo 607: #
608: # Example invocation:
609: #
610: # vif-bridge up domain=VM1 vif=xvif1.0 mac="ee:14:01:d0:ec:af" bridge=bridge0
611: #
612: #============================================================================
1.5 mspo 613:
1.3 mspo 614: # Exit if anything goes wrong
615: set -e
1.5 mspo 616:
1.3 mspo 617: echo "vif-bridge $*"
1.5 mspo 618:
1.3 mspo 619: # Operation name.
620: OP=$1; shift
1.5 mspo 621:
1.3 mspo 622: # Pull variables in args into environment
623: for arg ; do export "${arg}" ; done
1.5 mspo 624:
1.3 mspo 625: # Required parameters. Fail if not set.
626: domain=${domain:?}
627: vif=${vif:?}
628: mac=${mac:?}
629: bridge=${bridge:?}
1.5 mspo 630:
1.3 mspo 631: # Optional parameters. Set defaults.
632: ip=${ip:-''} # default to null (do nothing)
1.5 mspo 633:
1.3 mspo 634: # Are we going up or down?
635: case $OP in
1.5 mspo 636: up) brcmd='add' ;;
1.3 mspo 637: down) brcmd='delete' ;;
638: *)
1.5 mspo 639: echo 'Invalid command: ' $OP
640: echo 'Valid commands are: up, down'
641: exit 1
642: ;;
1.3 mspo 643: esac
1.5 mspo 644:
1.3 mspo 645: # Don't do anything if the bridge is "null".
646: if [ "${bridge}" = "null" ] ; then
1.5 mspo 647: exit
1.3 mspo 648: fi
1.5 mspo 649:
1.3 mspo 650: # Don't do anything if the bridge doesn't exist.
651: if ! ifconfig -l | grep "${bridge}" >/dev/null; then
1.5 mspo 652: exit
1.3 mspo 653: fi
1.5 mspo 654:
1.3 mspo 655: # Add/remove vif to/from bridge.
656: ifconfig x${vif} $OP
657: brconfig ${bridge} ${brcmd} x${vif}
1.1 mspo 658:
659: Now, running
660:
1.3 mspo 661: xm create -c /usr/pkg/etc/xen/nbsd
1.1 mspo 662:
1.5 mspo 663: should create a domain and load a NetBSD kernel in it. (Note: `-c`
664: causes xm to connect to the domain's console once created.) The kernel
665: will try to find its root file system on xbd0 (i.e., wd0e) which hasn't
666: been created yet. wd0e will be seen as a disk device in the new domain,
667: so it will be 'sub-partitioned'. We could attach a ccd to wd0e in
668: *domain0* and partition it, newfs and extract the NetBSD/i386 or amd64
669: tarballs there, but there's an easier way: load the
670: `netbsd-INSTALL_XEN3_DOMU` kernel provided in the NetBSD binary sets.
671: Like other install kernels, it contains a ramdisk with sysinst, so you
672: can install NetBSD using sysinst on your new domain.
1.1 mspo 673:
674: If you want to install NetBSD/Xen with a CDROM image, the following line
1.5 mspo 675: should be used in the `/usr/pkg/etc/xen/nbsd` file:
1.1 mspo 676:
1.3 mspo 677: disk = [ 'phy:/dev/wd0e,0x1,w', 'phy:/dev/cd0a,0x2,r' ]
1.1 mspo 678:
679: After booting the domain, the option to install via CDROM may be
1.5 mspo 680: selected. The CDROM device should be changed to `xbd1d`.
1.1 mspo 681:
1.5 mspo 682: Once done installing, `halt -p` the new domain (don't reboot or halt, it
683: would reload the INSTALL\_XEN3\_DOMU kernel even if you changed the
1.1 mspo 684: config file), switch the config file back to the XEN3\_DOMU kernel, and
1.5 mspo 685: start the new domain again. Now it should be able to use `root on xbd0a`
686: and you should have a second, functional NetBSD system on your xen
687: installation.
1.1 mspo 688:
689: When the new domain is booting you'll see some warnings about *wscons*
690: and the pseudo-terminals. These can be fixed by editing the files
1.5 mspo 691: `/etc/ttys` and `/etc/wscons.conf`. You must disable all terminals in
692: `/etc/ttys`, except *console*, like this:
1.1 mspo 693:
1.3 mspo 694: console "/usr/libexec/getty Pc" vt100 on secure
695: ttyE0 "/usr/libexec/getty Pc" vt220 off secure
696: ttyE1 "/usr/libexec/getty Pc" vt220 off secure
697: ttyE2 "/usr/libexec/getty Pc" vt220 off secure
698: ttyE3 "/usr/libexec/getty Pc" vt220 off secure
1.1 mspo 699:
1.5 mspo 700: Finally, all screens must be commented out from `/etc/wscons.conf`.
1.1 mspo 701:
702: It is also desirable to add
703:
1.3 mspo 704: powerd=YES
1.1 mspo 705:
1.5 mspo 706: in rc.conf. This way, the domain will be properly shut down if
707: `xm shutdown -R` or `xm shutdown -H` is used on the domain0.
1.1 mspo 708:
709: Your domain should be now ready to work, enjoy.
710:
1.14 gdt 711: Creating an unprivileged Linux domain (domU)
1.5 mspo 712: --------------------------------------------
1.1 mspo 713:
714: Creating unprivileged Linux domains isn't much different from
715: unprivileged NetBSD domains, but there are some details to know.
716:
717: First, the second parameter passed to the disk declaration (the '0x1' in
718: the example below)
719:
1.3 mspo 720: disk = [ 'phy:/dev/wd0e,0x1,w' ]
1.1 mspo 721:
722: does matter to Linux. It wants a Linux device number here (e.g. 0x300
723: for hda). Linux builds device numbers as: (major \<\< 8 + minor). So,
724: hda1 which has major 3 and minor 1 on a Linux system will have device
725: number 0x301. Alternatively, devices names can be used (hda, hdb, ...)
726: as xentools has a table to map these names to devices numbers. To export
727: a partition to a Linux guest we can use:
728:
1.3 mspo 729: disk = [ 'phy:/dev/wd0e,0x300,w' ]
730: root = "/dev/hda1 ro"
1.1 mspo 731:
732: and it will appear as /dev/hda on the Linux system, and be used as root
733: partition.
734:
735: To install the Linux system on the partition to be exported to the guest
736: domain, the following method can be used: install sysutils/e2fsprogs
737: from pkgsrc. Use mke2fs to format the partition that will be the root
738: partition of your Linux domain, and mount it. Then copy the files from a
1.5 mspo 739: working Linux system, make adjustments in `/etc` (fstab, network
740: config). It should also be possible to extract binary packages such as
741: .rpm or .deb directly to the mounted partition using the appropriate
742: tool, possibly running under NetBSD's Linux emulation. Once the
743: filesystem has been populated, umount it. If desirable, the filesystem
744: can be converted to ext3 using tune2fs -j. It should now be possible to
745: boot the Linux guest domain, using one of the vmlinuz-\*-xenU kernels
746: available in the Xen binary distribution.
1.1 mspo 747:
748: To get the linux console right, you need to add:
749:
1.3 mspo 750: extra = "xencons=tty1"
1.1 mspo 751:
752: to your configuration since not all linux distributions auto-attach a
753: tty to the xen console.
754:
1.14 gdt 755: Creating an unprivileged Solaris domain (domU)
1.5 mspo 756: ----------------------------------------------
1.1 mspo 757:
758: Download an Opensolaris [release](http://opensolaris.org/os/downloads/)
759: or [development snapshot](http://genunix.org/) DVD image. Attach the DVD
1.5 mspo 760: image to a MAN.VND.4 device. Copy the kernel and ramdisk filesystem
761: image to your dom0 filesystem.
1.1 mspo 762:
1.3 mspo 763: dom0# mkdir /root/solaris
764: dom0# vnconfig vnd0 osol-1002-124-x86.iso
765: dom0# mount /dev/vnd0a /mnt
1.5 mspo 766:
1.3 mspo 767: ## for a 64-bit guest
768: dom0# cp /mnt/boot/amd64/x86.microroot /root/solaris
769: dom0# cp /mnt/platform/i86xpv/kernel/amd64/unix /root/solaris
1.5 mspo 770:
1.3 mspo 771: ## for a 32-bit guest
772: dom0# cp /mnt/boot/x86.microroot /root/solaris
773: dom0# cp /mnt/platform/i86xpv/kernel/unix /root/solaris
1.5 mspo 774:
1.3 mspo 775: dom0# umount /mnt
1.5 mspo 776:
777:
778: Keep the MAN.VND.4 configured. For some reason the boot process stalls
779: unless the DVD image is attached to the guest as a "phy" device. Create
780: an initial configuration file with the following contents. Substitute
781: */dev/wd0k* with an empty partition at least 8 GB large.
1.1 mspo 782:
1.4 mspo 783: memory = 640
784: name = 'solaris'
785: disk = [ 'phy:/dev/wd0k,0,w' ]
786: disk += [ 'phy:/dev/vnd0d,6:cdrom,r' ]
787: vif = [ 'bridge=bridge0' ]
788: kernel = '/root/solaris/unix'
789: ramdisk = '/root/solaris/x86.microroot'
790: # for a 64-bit guest
791: extra = '/platform/i86xpv/kernel/amd64/unix - nowin -B install_media=cdrom'
792: # for a 32-bit guest
793: #extra = '/platform/i86xpv/kernel/unix - nowin -B install_media=cdrom'
1.5 mspo 794:
795:
1.1 mspo 796: Start the guest.
797:
1.4 mspo 798: dom0# xm create -c solaris.cfg
799: Started domain solaris
800: v3.3.2 chgset 'unavailable'
801: SunOS Release 5.11 Version snv_124 64-bit
802: Copyright 1983-2009 Sun Microsystems, Inc. All rights reserved.
803: Use is subject to license terms.
804: Hostname: opensolaris
805: Remounting root read/write
806: Probing for device nodes ...
807: WARNING: emlxs: ddi_modopen drv/fct failed: err 2
808: Preparing live image for use
809: Done mounting Live image
1.5 mspo 810:
1.1 mspo 811:
812: Make sure the network is configured. Note that it can take a minute for
813: the xnf0 interface to appear.
814:
1.4 mspo 815: opensolaris console login: jack
816: Password: jack
817: Sun Microsystems Inc. SunOS 5.11 snv_124 November 2008
818: jack@opensolaris:~$ pfexec sh
819: sh-3.2# ifconfig -a
820: sh-3.2# exit
1.5 mspo 821:
1.1 mspo 822:
823: Set a password for VNC and start the VNC server which provides the X11
824: display where the installation program runs.
825:
1.4 mspo 826: jack@opensolaris:~$ vncpasswd
827: Password: solaris
828: Verify: solaris
829: jack@opensolaris:~$ cp .Xclients .vnc/xstartup
830: jack@opensolaris:~$ vncserver :1
1.5 mspo 831:
1.1 mspo 832:
1.5 mspo 833: From a remote machine connect to the VNC server. Use `ifconfig xnf0` on
834: the guest to find the correct IP address to use.
1.1 mspo 835:
1.4 mspo 836: remote$ vncviewer 172.18.2.99:1
1.5 mspo 837:
1.1 mspo 838:
839: It is also possible to launch the installation on a remote X11 display.
840:
1.4 mspo 841: jack@opensolaris:~$ export DISPLAY=172.18.1.1:0
842: jack@opensolaris:~$ pfexec gui-install
1.5 mspo 843:
1.1 mspo 844:
845: After the GUI installation is complete you will be asked to reboot.
846: Before that you need to determine the ZFS ID for the new boot filesystem
847: and update the configuration file accordingly. Return to the guest
848: console.
849:
1.4 mspo 850: jack@opensolaris:~$ pfexec zdb -vvv rpool | grep bootfs
851: bootfs = 43
852: ^C
853: jack@opensolaris:~$
1.5 mspo 854:
1.1 mspo 855:
856: The final configuration file should look like this. Note in particular
857: the last line.
858:
1.4 mspo 859: memory = 640
860: name = 'solaris'
861: disk = [ 'phy:/dev/wd0k,0,w' ]
862: vif = [ 'bridge=bridge0' ]
863: kernel = '/root/solaris/unix'
864: ramdisk = '/root/solaris/x86.microroot'
865: extra = '/platform/i86xpv/kernel/amd64/unix -B zfs-bootfs=rpool/43,bootpath="/xpvd/xdf@0:a"'
1.5 mspo 866:
1.1 mspo 867:
868: Restart the guest to verify it works correctly.
869:
1.4 mspo 870: dom0# xm destroy solaris
871: dom0# xm create -c solaris.cfg
872: Using config file "./solaris.cfg".
873: v3.3.2 chgset 'unavailable'
874: Started domain solaris
875: SunOS Release 5.11 Version snv_124 64-bit
876: Copyright 1983-2009 Sun Microsystems, Inc. All rights reserved.
877: Use is subject to license terms.
878: WARNING: emlxs: ddi_modopen drv/fct failed: err 2
879: Hostname: osol
880: Configuring devices.
881: Loading smf(5) service descriptions: 160/160
882: svccfg import warnings. See /var/svc/log/system-manifest-import:default.log .
883: Reading ZFS config: done.
884: Mounting ZFS filesystems: (6/6)
885: Creating new rsa public/private host key pair
886: Creating new dsa public/private host key pair
1.5 mspo 887:
1.4 mspo 888: osol console login:
1.5 mspo 889:
1.1 mspo 890:
891: Using PCI devices in guest domains
1.14 gdt 892: ----------------------------------
1.1 mspo 893:
894: The domain0 can give other domains access to selected PCI devices. This
895: can allow, for example, a non-privileged domain to have access to a
896: physical network interface or disk controller. However, keep in mind
897: that giving a domain access to a PCI device most likely will give the
898: domain read/write access to the whole physical memory, as PCs don't have
899: an IOMMU to restrict memory access to DMA-capable device. Also, it's not
900: possible to export ISA devices to non-domain0 domains (which means that
901: the primary VGA adapter can't be exported. A guest domain trying to
902: access the VGA registers will panic).
903:
904: This functionality is only available in NetBSD-5.1 (and later) domain0
905: and domU. If the domain0 is NetBSD, it has to be running Xen 3.1, as
906: support has not been ported to later versions at this time.
907:
908: For a PCI device to be exported to a domU, is has to be attached to the
1.5 mspo 909: `pciback` driver in domain0. Devices passed to the domain0 via the
910: pciback.hide boot parameter will attach to `pciback` instead of the
911: usual driver. The list of devices is specified as `(bus:dev.func)`,
912: where bus and dev are 2-digit hexadecimal numbers, and func a
913: single-digit number:
1.1 mspo 914:
1.4 mspo 915: pciback.hide=(00:0a.0)(00:06.0)
1.1 mspo 916:
917: pciback devices should show up in the domain0's boot messages, and the
1.5 mspo 918: devices should be listed in the `/kern/xen/pci` directory.
1.1 mspo 919:
1.5 mspo 920: PCI devices to be exported to a domU are listed in the `pci` array of
921: the domU's config file, with the format `'0000:bus:dev.func'`
1.1 mspo 922:
1.4 mspo 923: pci = [ '0000:00:06.0', '0000:00:0a.0' ]
1.1 mspo 924:
1.5 mspo 925: In the domU an `xpci` device will show up, to which one or more pci
926: busses will attach. Then the PCI drivers will attach to PCI busses as
927: usual. Note that the default NetBSD DOMU kernels do not have `xpci` or
928: any PCI drivers built in by default; you have to build your own kernel
929: to use PCI devices in a domU. Here's a kernel config example:
1.1 mspo 930:
1.4 mspo 931: include "arch/i386/conf/XEN3_DOMU"
932: #include "arch/i386/conf/XENU" # in NetBSD 3.0
1.5 mspo 933:
1.4 mspo 934: # Add support for PCI busses to the XEN3_DOMU kernel
935: xpci* at xenbus ?
936: pci* at xpci ?
1.5 mspo 937:
1.4 mspo 938: # Now add PCI and related devices to be used by this domain
939: # USB Controller and Devices
1.5 mspo 940:
1.4 mspo 941: # PCI USB controllers
942: uhci* at pci? dev ? function ? # Universal Host Controller (Intel)
1.5 mspo 943:
1.4 mspo 944: # USB bus support
945: usb* at uhci?
1.5 mspo 946:
1.4 mspo 947: # USB Hubs
948: uhub* at usb?
949: uhub* at uhub? port ? configuration ? interface ?
1.5 mspo 950:
1.4 mspo 951: # USB Mass Storage
952: umass* at uhub? port ? configuration ? interface ?
953: wd* at umass?
954: # SCSI controllers
955: ahc* at pci? dev ? function ? # Adaptec [23]94x, aic78x0 SCSI
1.5 mspo 956:
1.4 mspo 957: # SCSI bus support (for both ahc and umass)
958: scsibus* at scsi?
1.5 mspo 959:
1.4 mspo 960: # SCSI devices
961: sd* at scsibus? target ? lun ? # SCSI disk drives
962: cd* at scsibus? target ? lun ? # SCSI CD-ROM drives
1.1 mspo 963:
964:
1.28 gdt 965: NetBSD as a domU in a VPS
966: =========================
967:
968: The bulk of the HOWTO is about using NetBSD as a dom0 on your own
969: hardware. This section explains how to deal with Xen in a domU as a
970: virtual private server where you do not control or have access to the
971: dom0.
972:
973: TODO: Perhaps reference panix, prmgr, amazon as interesting examples.
974:
975: TODO: Somewhere, discuss pvgrub and py-grub to load the domU kernel
976: from the domU filesystem.
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