Annotation of wikisrc/ports/xen/howto.mdwn, revision 1.43
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:
1.36 gdt 155: Build problems
156: --------------
157:
158: Ideally, all versions of Xen in pkgsrc would build on all versions of
159: NetBSD on both i386 and amd64. However, that isn't the case. Besides
160: aging code and aging compilers, qemu (included in xentools for HVM
161: support) is difficult to build. The following are known to fail:
162:
163: xenkernel3 netbsd-6 i386
164: xentools42 netbsd-6 i386
165:
166: The following are known to work:
167:
168: xenkernel41 netbsd-5 amd64
169: xentools41 netbsd-5 amd64
170: xenkernel41 netbsd-6 i386
171: xentools41 netbsd-6 i386
172:
1.15 gdt 173: NetBSD as a dom0
174: ================
175:
176: NetBSD can be used as a dom0 and works very well. The following
177: sections address installation, updating NetBSD, and updating Xen.
1.19 gdt 178: Note that it doesn't make sense to talk about installing a dom0 OS
179: without also installing Xen itself. We first address installing
180: NetBSD, which is not yet a dom0, and then adding Xen, pivoting the
181: NetBSD install to a dom0 install by just changing the kernel and boot
182: configuration.
1.15 gdt 183:
184: Styles of dom0 operation
185: ------------------------
186:
187: There are two basic ways to use Xen. The traditional method is for
188: the dom0 to do absolutely nothing other than providing support to some
189: number of domUs. Such a system was probably installed for the sole
190: purpose of hosting domUs, and sits in a server room on a UPS.
191:
192: The other way is to put Xen under a normal-usage computer, so that the
193: dom0 is what the computer would have been without Xen, perhaps a
194: desktop or laptop. Then, one can run domUs at will. Purists will
195: deride this as less secure than the previous approach, and for a
196: computer whose purpose is to run domUs, they are right. But Xen and a
197: dom0 (without domUs) is not meaingfully less secure than the same
198: things running without Xen. One can boot Xen or boot regular NetBSD
199: alternately with little problems, simply refraining from starting the
200: Xen daemons when not running Xen.
201:
202: Note that NetBSD as dom0 does not support multiple CPUs. This will
203: limit the performance of the Xen/dom0 workstation approach.
204:
1.19 gdt 205: Installation of NetBSD
206: ----------------------
1.13 gdt 207:
1.19 gdt 208: First,
1.27 jnemeth 209: [install NetBSD/amd64](/guide/inst/)
1.19 gdt 210: just as you would if you were not using Xen.
211: However, the partitioning approach is very important.
212:
213: If you want to use RAIDframe for the dom0, there are no special issues
214: for Xen. Typically one provides RAID storage for the dom0, and the
1.22 gdt 215: domU systems are unaware of RAID. The 2nd-stage loader bootxx_* skips
216: over a RAID1 header to find /boot from a filesystem within a RAID
217: partition; this is no different when booting Xen.
1.19 gdt 218:
219: There are 4 styles of providing backing storage for the virtual disks
220: used by domUs: raw partitions, LVM, file-backed vnd(4), and SAN,
221:
222: With raw partitions, one has a disklabel (or gpt) partition sized for
223: each virtual disk to be used by the domU. (If you are able to predict
224: how domU usage will evolve, please add an explanation to the HOWTO.
225: Seriously, needs tend to change over time.)
226:
1.27 jnemeth 227: One can use [lvm(8)](/guide/lvm/) to create logical devices to use
228: for domU disks. This is almost as efficient as raw disk partitions
229: and more flexible. Hence raw disk partitions should typically not
230: be used.
1.19 gdt 231:
232: One can use files in the dom0 filesystem, typically created by dd'ing
233: /dev/zero to create a specific size. This is somewhat less efficient,
234: but very convenient, as one can cp the files for backup, or move them
235: between dom0 hosts.
236:
237: Finally, in theory one can place the files backing the domU disks in a
238: SAN. (This is an invitation for someone who has done this to add a
239: HOWTO page.)
1.1 mspo 240:
1.19 gdt 241: Installation of Xen
242: -------------------
1.1 mspo 243:
1.20 gdt 244: In the dom0, install sysutils/xenkernel42 and sysutils/xentools42 from
245: pkgsrc (or another matching pair).
246: See [the pkgsrc
247: documentation](http://www.NetBSD.org/docs/pkgsrc/) for help with pkgsrc.
248:
249: For Xen 3.1, support for HVM guests is in sysutils/xentool3-hvm. More
250: recent versions have HVM support integrated in the main xentools
251: package. It is entirely reasonable to run only PV guests.
252:
253: Next you need to install the selected Xen kernel itself, which is
254: installed by pkgsrc as "/usr/pkg/xen*-kernel/xen.gz". Copy it to /.
255: For debugging, one may copy xen-debug.gz; this is conceptually similar
256: to DIAGNOSTIC and DEBUG in NetBSD. xen-debug.gz is basically only
257: useful with a serial console. Then, place a NetBSD XEN3_DOM0 kernel
258: in /, copied from releasedir/amd64/binary/kernel/netbsd-XEN3_DOM0.gz
259: of a NetBSD build. Both xen and NetBSD may be left compressed. (If
260: using i386, use releasedir/i386/binary/kernel/netbsd-XEN3PAE_DOM0.gz.)
261:
262: In a dom0 kernel, kernfs is mandatory for xend to comunicate with the
263: kernel, so ensure that /kern is in fstab.
264:
265: Because you already installed NetBSD, you have a working boot setup
266: with an MBR bootblock, either bootxx_ffsv1 or bootxx_ffsv2 at the
267: beginning of your root filesystem, /boot present, and likely
268: /boot.cfg. (If not, fix before continuing!)
269:
270: See boot.cfg(5) for an example. The basic line is
271:
1.37 gdt 272: menu=Xen:load /netbsd-XEN3_DOM0.gz console=pc;multiboot /xen.gz dom0_mem=256M
1.20 gdt 273:
274: which specifies that the dom0 should have 256M, leaving the rest to be
1.37 gdt 275: allocated for domUs. In an attempt to add performance, one can also
276: add
277:
278: dom0_max_vcpus=1 dom0_vcpus_pin
279:
280: to force only one vcpu to be provided (since NetBSD dom0 can't use
281: more) and to pin that vcpu to a physical cpu. TODO: benchmark this.
1.20 gdt 282:
283: As with non-Xen systems, you should have a line to boot /netbsd (a
284: kernel that works without Xen) and fallback versions of the non-Xen
285: kernel, Xen, and the dom0 kernel.
1.1 mspo 286:
1.28 gdt 287: The [HowTo on Installing into
288: RAID-1](http://mail-index.NetBSD.org/port-xen/2006/03/01/0010.html)
289: explains how to set up booting a dom0 with Xen using grub with
290: NetBSD's RAIDframe. (This is obsolete with the use of NetBSD's native
291: boot.)
292:
1.21 gdt 293: Configuring Xen
294: ---------------
295:
296: Now, you have a system that will boot Xen and the dom0 kernel, and
297: just run the dom0 kernel. There will be no domUs, and none can be
1.31 gdt 298: started because you still have to configure the dom0 tools. The
299: daemons which should be run vary with Xen version and with whether one
300: is using xm or xl. Note that xend is for supporting "xm", and should
301: only be used if you plan on using "xm". Do NOT enable xend if you
302: plan on using "xl" as it will cause problems.
1.21 gdt 303:
1.43 ! gdt 304: The installation of NetBSD should already have created devices for xen
! 305: (xencons, xenevt), but if they are not present, create them:
! 306:
! 307: cd /dev && sh MAKEDEV xen
! 308:
1.31 gdt 309: TODO: Give 3.1 advice (or remove it from pkgsrc).
310:
311: For 3.3 (and thus xm), add to rc.conf (but note that you should have
312: installed 4.1 or 4.2):
313:
1.32 gdt 314: xend=YES
315: xenbackendd=YES
1.31 gdt 316:
1.33 gdt 317: For 4.1 (and thus xm; xl is believed not to work well), add to rc.conf:
1.31 gdt 318:
319: xend=YES
320: xencommons=YES
321:
322: TODO: Explain why if xm is preferred on 4.1, rc.d/xendomains has xl.
1.33 gdt 323: Or fix the package.
1.31 gdt 324:
1.33 gdt 325: For 4.2 with xm, add to rc.conf
326:
327: xend=YES
328: xencommons=YES
329:
330: For 4.2 with xl (preferred), add to rc.conf:
1.31 gdt 331:
332: TODO: explain if there is a xend replacement
333: xencommons=YES
334:
335: TODO: Recommend for/against xen-watchdog.
1.27 jnemeth 336:
1.43 ! gdt 337: After you have configured the daemons and either started them or
1.42 gdt 338: rebooted, run the following (or use xl) to inspect Xen's boot
339: messages, available resources, and running domains:
1.34 gdt 340:
1.43 ! gdt 341: # xm dmesg
! 342: [xen's boot info]
! 343: # xm info
! 344: [available memory, etc.]
! 345: # xm list
! 346: Name Id Mem(MB) CPU State Time(s) Console
! 347: Domain-0 0 64 0 r---- 58.1
1.33 gdt 348:
1.41 gdt 349: anita (for testing NetBSD)
350: --------------------------
351:
352: With the setup so far, one should be able to run anita (see
353: pkgsrc/sysutils/py-anita) to test NetBSD releases, by doing (as root,
354: because anita must create a domU):
355:
356: anita --vmm=xm test file:///usr/obj/i386/
357:
358: Alternatively, one can use --vmm=xl to use xl-based domU creation instead.
359: TODO: check this.
360:
1.40 gdt 361: Xen-specific NetBSD issues
362: --------------------------
363:
364: There are (at least) two additional things different about NetBSD as a
365: dom0 kernel compared to hardware.
366:
367: One is that modules are not usable in DOM0 kernels, so one must
368: compile in what's needed. It's not really that modules cannot work,
369: but that modules must be built for XEN3_DOM0 because some of the
370: defines change and the normal module builds don't do this. Basically,
371: enabling Xen changes the kernel ABI, and the module build system
372: doesn't cope with this.
373:
374: The other difference is that XEN3_DOM0 does not have exactly the same
375: options as GENERIC. While it is debatable whether or not this is a
376: bug, users should be aware of this and can simply add missing config
377: items if desired.
378:
1.15 gdt 379: Updating NetBSD in a dom0
380: -------------------------
381:
382: This is just like updating NetBSD on bare hardware, assuming the new
383: version supports the version of Xen you are running. Generally, one
384: replaces the kernel and reboots, and then overlays userland binaries
385: and adjusts /etc.
386:
387: Note that one must update both the non-Xen kernel typically used for
388: rescue purposes and the DOM0 kernel used with Xen.
389:
1.22 gdt 390: To convert from grub to /boot, install an mbr bootblock with fdisk,
391: bootxx_ with installboot, /boot and /boot.cfg. This really should be
392: no different than completely reinstalling boot blocks on a non-Xen
393: system.
394:
1.15 gdt 395: Updating Xen versions
396: ---------------------
397:
1.21 gdt 398: Updating Xen is conceptually not difficult, but can run into all the
399: issues found when installing Xen. Assuming migration from 4.1 to 4.2,
400: remove the xenkernel41 and xentools41 packages and install the
401: xenkernel42 and xentools42 packages. Copy the 4.2 xen.gz to /.
402:
403: Ensure that the contents of /etc/rc.d/xen* are correct. Enable the
404: correct set of daemons. Ensure that the domU config files are valid
405: for the new version.
1.15 gdt 406:
1.28 gdt 407:
408: Unprivileged domains (domU)
409: ===========================
410:
411: This section describes general concepts about domUs. It does not
1.33 gdt 412: address specific domU operating systems or how to install them. The
413: config files for domUs are typically in /usr/pkg/etc/xen, and are
414: typically named so that the file anme, domU name and the domU's host
415: name match.
416:
417: The domU is provided with cpu and memory by Xen, configured by the
418: dom0. The domU is provided with disk and network by the dom0,
419: mediated by Xen, and configured in the dom0.
420:
421: Entropy in domUs can be an issue; physical disks and network are on
422: the dom0. NetBSD's /dev/random system works, but is often challenged.
423:
424: CPU and memory
425: --------------
426:
427: A domain is provided with some number of vcpus, less than the
428: number of cpus seen by the hypervisor. For a dom0, this is controlled
429: by the boot argument "dom0_max_vcpus=1". For a domU, it is controlled
430: from the config file.
431:
432: A domain is provided with memory, In the straightforward case, the sum
433: of the the memory allocated to the dom0 and all domUs must be less
434: than the available memory.
435:
436: Xen also provides a "balloon" driver, which can be used to let domains
437: use more memory temporarily. TODO: Explain better, and explain how
438: well it works with NetBSD.
1.28 gdt 439:
440: Virtual disks
441: -------------
442:
1.33 gdt 443: With the file/vnd style, typically one creates a directory,
444: e.g. /u0/xen, on a disk large enough to hold virtual disks for all
445: domUs. Then, for each domU disk, one writes zeros to a file that then
446: serves to hold the virtual disk's bits; a suggested name is foo-xbd0
447: for the first virtual disk for the domU called foo. Writing zeros to
448: the file serves two purposes. One is that preallocating the contents
449: improves performance. The other is that vnd on sparse files has
450: failed to work. TODO: give working/notworking NetBSD versions for
451: sparse vnd. Note that the use of file/vnd for Xen is not really
452: different than creating a file-backed virtual disk for some other
1.39 gdt 453: purpose, except that xentools handles the vnconfig commands. To
454: create an empty 4G virtual disk, simply do
455:
456: dd if=/dev/zero of=foo-xbd0 bs=1m count=4096
1.33 gdt 457:
458: With the lvm style, one creates logical devices. They are then used
459: similarly to vnds.
1.28 gdt 460:
461: Virtual Networking
462: ------------------
463:
464: TODO: explain xvif concept, and that it's general.
465:
466: There are two normal styles: bridging and NAT.
467:
468: With bridging, the domU perceives itself to be on the same network as
469: the dom0. For server virtualization, this is usually best.
470:
471: With NAT, the domU perceives itself to be behind a NAT running on the
472: dom0. This is often appropriate when running Xen on a workstation.
473:
474: One can construct arbitrary other configurations, but there is no
475: script support.
476:
1.33 gdt 477: Sizing domains
478: --------------
479:
480: Modern x86 hardware has vast amounts of resources. However, many
481: virtual servers can function just fine on far less. A system with
482: 256M of RAM and a 4G disk can be a reasonable choice. Note that it is
483: far easier to adjust virtual resources than physical ones. For
484: memory, it's just a config file edit and a reboot. For disk, one can
485: create a new file and vnconfig it (or lvm), and then dump/restore,
486: just like updating physical disks, but without having to be there and
487: without those pesky connectors.
488:
1.39 gdt 489: domU kernels
490: ------------
491:
492: On a physical computer, the BIOS reads sector 0, and a chain of boot
493: loaders finds and loads a kernel. Normally this comes from the root
494: filesystem. With Xen domUs, the process is totally different. The
495: normal path is for the domU kernel to be a file in the dom0's
496: filesystem. At the request of the dom0, Xen loads that kernel into a
497: new domU instance and starts execution. While domU kernels can be
498: anyplace, reasonable places to store domU kernels on the dom0 are in /
499: (so they are near the dom0 kernel), in /usr/pkg/etc/xen (near the
500: config files), or in /u0/xen (where the vdisks are).
501:
502: See the VPS section near the end for discussion of alternate ways to
503: obtain domU kernels.
504:
1.28 gdt 505: Config files
506: ------------
507:
508: TODO: give example config files. Use both lvm and vnd.
509:
510: TODO: explain the mess with 3 arguments for disks and how to cope (0x1).
511:
512: Starting domains
513: ----------------
514:
515: TODO: Explain "xm start" and "xl start". Explain rc.d/xendomains.
516:
517: TODO: Explain why 4.1 rc.d/xendomains has xl, when one should use xm
518: on 4.1.
519:
520: Creating specific unprivileged domains (domU)
521: =============================================
1.14 gdt 522:
523: Creating domUs is almost entirely independent of operating system. We
524: first explain NetBSD, and then differences for Linux and Solaris.
1.43 ! gdt 525: Note that you must have already completed the dom0 setup so that "xm
! 526: list" (or "xl list") works.
1.14 gdt 527:
528: Creating an unprivileged NetBSD domain (domU)
529: ---------------------------------------------
1.1 mspo 530:
531: 'xm create' allows you to create a new domain. It uses a config file in
532: PKG\_SYSCONFDIR for its parameters. By default, this file will be in
1.5 mspo 533: `/usr/pkg/etc/xen/`. On creation, a kernel has to be specified, which
534: will be executed in the new domain (this kernel is in the *domain0* file
535: system, not on the new domain virtual disk; but please note, you should
536: install the same kernel into *domainU* as `/netbsd` in order to make
1.27 jnemeth 537: your system tools, like savecore(8), work). A suitable kernel is
1.5 mspo 538: provided as part of the i386 and amd64 binary sets: XEN3\_DOMU.
1.1 mspo 539:
540: Here is an /usr/pkg/etc/xen/nbsd example config file:
541:
1.3 mspo 542: # -*- mode: python; -*-
543: #============================================================================
544: # Python defaults setup for 'xm create'.
545: # Edit this file to reflect the configuration of your system.
546: #============================================================================
1.5 mspo 547:
1.3 mspo 548: #----------------------------------------------------------------------------
549: # Kernel image file. This kernel will be loaded in the new domain.
550: kernel = "/home/bouyer/netbsd-XEN3_DOMU"
551: #kernel = "/home/bouyer/netbsd-INSTALL_XEN3_DOMU"
1.5 mspo 552:
1.3 mspo 553: # Memory allocation (in megabytes) for the new domain.
554: memory = 128
1.5 mspo 555:
1.3 mspo 556: # A handy name for your new domain. This will appear in 'xm list',
557: # and you can use this as parameters for xm in place of the domain
558: # number. All domains must have different names.
559: #
560: name = "nbsd"
1.5 mspo 561:
1.3 mspo 562: # The number of virtual CPUs this domain has.
563: #
564: vcpus = 1
1.5 mspo 565:
1.3 mspo 566: #----------------------------------------------------------------------------
567: # Define network interfaces for the new domain.
1.5 mspo 568:
1.3 mspo 569: # Number of network interfaces (must be at least 1). Default is 1.
570: nics = 1
1.5 mspo 571:
1.3 mspo 572: # Define MAC and/or bridge for the network interfaces.
573: #
574: # The MAC address specified in ``mac'' is the one used for the interface
575: # in the new domain. The interface in domain0 will use this address XOR'd
576: # with 00:00:00:01:00:00 (i.e. aa:00:00:51:02:f0 in our example). Random
577: # MACs are assigned if not given.
578: #
579: # ``bridge'' is a required parameter, which will be passed to the
580: # vif-script called by xend(8) when a new domain is created to configure
581: # the new xvif interface in domain0.
582: #
583: # In this example, the xvif is added to bridge0, which should have been
584: # set up prior to the new domain being created -- either in the
585: # ``network'' script or using a /etc/ifconfig.bridge0 file.
586: #
587: vif = [ 'mac=aa:00:00:50:02:f0, bridge=bridge0' ]
1.5 mspo 588:
1.3 mspo 589: #----------------------------------------------------------------------------
590: # Define the disk devices you want the domain to have access to, and
591: # what you want them accessible as.
592: #
593: # Each disk entry is of the form:
594: #
1.5 mspo 595: # phy:DEV,VDEV,MODE
1.3 mspo 596: #
597: # where DEV is the device, VDEV is the device name the domain will see,
598: # and MODE is r for read-only, w for read-write. You can also create
599: # file-backed domains using disk entries of the form:
600: #
1.5 mspo 601: # file:PATH,VDEV,MODE
1.3 mspo 602: #
603: # where PATH is the path to the file used as the virtual disk, and VDEV
604: # and MODE have the same meaning as for ``phy'' devices.
605: #
606: # VDEV doesn't really matter for a NetBSD guest OS (it's just used as an index),
607: # but it does for Linux.
608: # Worse, the device has to exist in /dev/ of domain0, because xm will
609: # try to stat() it. This means that in order to load a Linux guest OS
610: # from a NetBSD domain0, you'll have to create /dev/hda1, /dev/hda2, ...
611: # on domain0, with the major/minor from Linux :(
612: # Alternatively it's possible to specify the device number in hex,
613: # e.g. 0x301 for /dev/hda1, 0x302 for /dev/hda2, etc ...
1.5 mspo 614:
1.3 mspo 615: disk = [ 'phy:/dev/wd0e,0x1,w' ]
616: #disk = [ 'file:/var/xen/nbsd-disk,0x01,w' ]
617: #disk = [ 'file:/var/xen/nbsd-disk,0x301,w' ]
1.5 mspo 618:
1.3 mspo 619: #----------------------------------------------------------------------------
620: # Set the kernel command line for the new domain.
1.5 mspo 621:
1.3 mspo 622: # Set root device. This one does matter for NetBSD
623: root = "xbd0"
624: # extra parameters passed to the kernel
625: # this is where you can set boot flags like -s, -a, etc ...
626: #extra = ""
1.5 mspo 627:
1.3 mspo 628: #----------------------------------------------------------------------------
629: # Set according to whether you want the domain restarted when it exits.
630: # The default is False.
631: #autorestart = True
1.5 mspo 632:
1.3 mspo 633: # end of nbsd config file ====================================================
1.1 mspo 634:
635: When a new domain is created, xen calls the
1.5 mspo 636: `/usr/pkg/etc/xen/vif-bridge` script for each virtual network interface
637: created in *domain0*. This can be used to automatically configure the
638: xvif?.? interfaces in *domain0*. In our example, these will be bridged
639: with the bridge0 device in *domain0*, but the bridge has to exist first.
640: To do this, create the file `/etc/ifconfig.bridge0` and make it look
641: like this:
1.1 mspo 642:
1.3 mspo 643: create
644: !brconfig $int add ex0 up
1.1 mspo 645:
1.5 mspo 646: (replace `ex0` with the name of your physical interface). Then bridge0
1.27 jnemeth 647: will be created on boot. See the bridge(4) man page for details.
1.1 mspo 648:
1.5 mspo 649: So, here is a suitable `/usr/pkg/etc/xen/vif-bridge` for xvif?.? (a
650: working vif-bridge is also provided with xentools20) configuring:
1.1 mspo 651:
1.5 mspo 652: #!/bin/sh
1.3 mspo 653: #============================================================================
1.43 ! gdt 654: # $NetBSD: howto.mdwn,v 1.42 2014/12/26 13:10:00 gdt Exp $
1.3 mspo 655: #
656: # /usr/pkg/etc/xen/vif-bridge
657: #
658: # Script for configuring a vif in bridged mode with a dom0 interface.
659: # The xend(8) daemon calls a vif script when bringing a vif up or down.
660: # The script name to use is defined in /usr/pkg/etc/xen/xend-config.sxp
661: # in the ``vif-script'' field.
662: #
663: # Usage: vif-bridge up|down [var=value ...]
664: #
665: # Actions:
1.5 mspo 666: # up Adds the vif interface to the bridge.
667: # down Removes the vif interface from the bridge.
1.3 mspo 668: #
669: # Variables:
1.5 mspo 670: # domain name of the domain the interface is on (required).
671: # vifq vif interface name (required).
672: # mac vif MAC address (required).
673: # bridge bridge to add the vif to (required).
1.3 mspo 674: #
675: # Example invocation:
676: #
677: # vif-bridge up domain=VM1 vif=xvif1.0 mac="ee:14:01:d0:ec:af" bridge=bridge0
678: #
679: #============================================================================
1.5 mspo 680:
1.3 mspo 681: # Exit if anything goes wrong
682: set -e
1.5 mspo 683:
1.3 mspo 684: echo "vif-bridge $*"
1.5 mspo 685:
1.3 mspo 686: # Operation name.
687: OP=$1; shift
1.5 mspo 688:
1.3 mspo 689: # Pull variables in args into environment
690: for arg ; do export "${arg}" ; done
1.5 mspo 691:
1.3 mspo 692: # Required parameters. Fail if not set.
693: domain=${domain:?}
694: vif=${vif:?}
695: mac=${mac:?}
696: bridge=${bridge:?}
1.5 mspo 697:
1.3 mspo 698: # Optional parameters. Set defaults.
699: ip=${ip:-''} # default to null (do nothing)
1.5 mspo 700:
1.3 mspo 701: # Are we going up or down?
702: case $OP in
1.5 mspo 703: up) brcmd='add' ;;
1.3 mspo 704: down) brcmd='delete' ;;
705: *)
1.5 mspo 706: echo 'Invalid command: ' $OP
707: echo 'Valid commands are: up, down'
708: exit 1
709: ;;
1.3 mspo 710: esac
1.5 mspo 711:
1.3 mspo 712: # Don't do anything if the bridge is "null".
713: if [ "${bridge}" = "null" ] ; then
1.5 mspo 714: exit
1.3 mspo 715: fi
1.5 mspo 716:
1.3 mspo 717: # Don't do anything if the bridge doesn't exist.
718: if ! ifconfig -l | grep "${bridge}" >/dev/null; then
1.5 mspo 719: exit
1.3 mspo 720: fi
1.5 mspo 721:
1.3 mspo 722: # Add/remove vif to/from bridge.
723: ifconfig x${vif} $OP
724: brconfig ${bridge} ${brcmd} x${vif}
1.1 mspo 725:
726: Now, running
727:
1.3 mspo 728: xm create -c /usr/pkg/etc/xen/nbsd
1.1 mspo 729:
1.5 mspo 730: should create a domain and load a NetBSD kernel in it. (Note: `-c`
731: causes xm to connect to the domain's console once created.) The kernel
732: will try to find its root file system on xbd0 (i.e., wd0e) which hasn't
733: been created yet. wd0e will be seen as a disk device in the new domain,
734: so it will be 'sub-partitioned'. We could attach a ccd to wd0e in
735: *domain0* and partition it, newfs and extract the NetBSD/i386 or amd64
736: tarballs there, but there's an easier way: load the
737: `netbsd-INSTALL_XEN3_DOMU` kernel provided in the NetBSD binary sets.
738: Like other install kernels, it contains a ramdisk with sysinst, so you
739: can install NetBSD using sysinst on your new domain.
1.1 mspo 740:
741: If you want to install NetBSD/Xen with a CDROM image, the following line
1.5 mspo 742: should be used in the `/usr/pkg/etc/xen/nbsd` file:
1.1 mspo 743:
1.3 mspo 744: disk = [ 'phy:/dev/wd0e,0x1,w', 'phy:/dev/cd0a,0x2,r' ]
1.1 mspo 745:
746: After booting the domain, the option to install via CDROM may be
1.5 mspo 747: selected. The CDROM device should be changed to `xbd1d`.
1.1 mspo 748:
1.5 mspo 749: Once done installing, `halt -p` the new domain (don't reboot or halt, it
750: would reload the INSTALL\_XEN3\_DOMU kernel even if you changed the
1.1 mspo 751: config file), switch the config file back to the XEN3\_DOMU kernel, and
1.5 mspo 752: start the new domain again. Now it should be able to use `root on xbd0a`
753: and you should have a second, functional NetBSD system on your xen
754: installation.
1.1 mspo 755:
756: When the new domain is booting you'll see some warnings about *wscons*
757: and the pseudo-terminals. These can be fixed by editing the files
1.5 mspo 758: `/etc/ttys` and `/etc/wscons.conf`. You must disable all terminals in
759: `/etc/ttys`, except *console*, like this:
1.1 mspo 760:
1.3 mspo 761: console "/usr/libexec/getty Pc" vt100 on secure
762: ttyE0 "/usr/libexec/getty Pc" vt220 off secure
763: ttyE1 "/usr/libexec/getty Pc" vt220 off secure
764: ttyE2 "/usr/libexec/getty Pc" vt220 off secure
765: ttyE3 "/usr/libexec/getty Pc" vt220 off secure
1.1 mspo 766:
1.5 mspo 767: Finally, all screens must be commented out from `/etc/wscons.conf`.
1.1 mspo 768:
769: It is also desirable to add
770:
1.3 mspo 771: powerd=YES
1.1 mspo 772:
1.5 mspo 773: in rc.conf. This way, the domain will be properly shut down if
774: `xm shutdown -R` or `xm shutdown -H` is used on the domain0.
1.1 mspo 775:
776: Your domain should be now ready to work, enjoy.
777:
1.14 gdt 778: Creating an unprivileged Linux domain (domU)
1.5 mspo 779: --------------------------------------------
1.1 mspo 780:
781: Creating unprivileged Linux domains isn't much different from
782: unprivileged NetBSD domains, but there are some details to know.
783:
784: First, the second parameter passed to the disk declaration (the '0x1' in
785: the example below)
786:
1.3 mspo 787: disk = [ 'phy:/dev/wd0e,0x1,w' ]
1.1 mspo 788:
789: does matter to Linux. It wants a Linux device number here (e.g. 0x300
790: for hda). Linux builds device numbers as: (major \<\< 8 + minor). So,
791: hda1 which has major 3 and minor 1 on a Linux system will have device
792: number 0x301. Alternatively, devices names can be used (hda, hdb, ...)
793: as xentools has a table to map these names to devices numbers. To export
794: a partition to a Linux guest we can use:
795:
1.3 mspo 796: disk = [ 'phy:/dev/wd0e,0x300,w' ]
797: root = "/dev/hda1 ro"
1.1 mspo 798:
799: and it will appear as /dev/hda on the Linux system, and be used as root
800: partition.
801:
802: To install the Linux system on the partition to be exported to the guest
803: domain, the following method can be used: install sysutils/e2fsprogs
804: from pkgsrc. Use mke2fs to format the partition that will be the root
805: partition of your Linux domain, and mount it. Then copy the files from a
1.5 mspo 806: working Linux system, make adjustments in `/etc` (fstab, network
807: config). It should also be possible to extract binary packages such as
808: .rpm or .deb directly to the mounted partition using the appropriate
809: tool, possibly running under NetBSD's Linux emulation. Once the
810: filesystem has been populated, umount it. If desirable, the filesystem
811: can be converted to ext3 using tune2fs -j. It should now be possible to
812: boot the Linux guest domain, using one of the vmlinuz-\*-xenU kernels
813: available in the Xen binary distribution.
1.1 mspo 814:
815: To get the linux console right, you need to add:
816:
1.3 mspo 817: extra = "xencons=tty1"
1.1 mspo 818:
819: to your configuration since not all linux distributions auto-attach a
820: tty to the xen console.
821:
1.14 gdt 822: Creating an unprivileged Solaris domain (domU)
1.5 mspo 823: ----------------------------------------------
1.1 mspo 824:
825: Download an Opensolaris [release](http://opensolaris.org/os/downloads/)
826: or [development snapshot](http://genunix.org/) DVD image. Attach the DVD
1.5 mspo 827: image to a MAN.VND.4 device. Copy the kernel and ramdisk filesystem
828: image to your dom0 filesystem.
1.1 mspo 829:
1.3 mspo 830: dom0# mkdir /root/solaris
831: dom0# vnconfig vnd0 osol-1002-124-x86.iso
832: dom0# mount /dev/vnd0a /mnt
1.5 mspo 833:
1.3 mspo 834: ## for a 64-bit guest
835: dom0# cp /mnt/boot/amd64/x86.microroot /root/solaris
836: dom0# cp /mnt/platform/i86xpv/kernel/amd64/unix /root/solaris
1.5 mspo 837:
1.3 mspo 838: ## for a 32-bit guest
839: dom0# cp /mnt/boot/x86.microroot /root/solaris
840: dom0# cp /mnt/platform/i86xpv/kernel/unix /root/solaris
1.5 mspo 841:
1.3 mspo 842: dom0# umount /mnt
1.5 mspo 843:
844:
845: Keep the MAN.VND.4 configured. For some reason the boot process stalls
846: unless the DVD image is attached to the guest as a "phy" device. Create
847: an initial configuration file with the following contents. Substitute
848: */dev/wd0k* with an empty partition at least 8 GB large.
1.1 mspo 849:
1.4 mspo 850: memory = 640
851: name = 'solaris'
852: disk = [ 'phy:/dev/wd0k,0,w' ]
853: disk += [ 'phy:/dev/vnd0d,6:cdrom,r' ]
854: vif = [ 'bridge=bridge0' ]
855: kernel = '/root/solaris/unix'
856: ramdisk = '/root/solaris/x86.microroot'
857: # for a 64-bit guest
858: extra = '/platform/i86xpv/kernel/amd64/unix - nowin -B install_media=cdrom'
859: # for a 32-bit guest
860: #extra = '/platform/i86xpv/kernel/unix - nowin -B install_media=cdrom'
1.5 mspo 861:
862:
1.1 mspo 863: Start the guest.
864:
1.4 mspo 865: dom0# xm create -c solaris.cfg
866: Started domain solaris
867: v3.3.2 chgset 'unavailable'
868: SunOS Release 5.11 Version snv_124 64-bit
869: Copyright 1983-2009 Sun Microsystems, Inc. All rights reserved.
870: Use is subject to license terms.
871: Hostname: opensolaris
872: Remounting root read/write
873: Probing for device nodes ...
874: WARNING: emlxs: ddi_modopen drv/fct failed: err 2
875: Preparing live image for use
876: Done mounting Live image
1.5 mspo 877:
1.1 mspo 878:
879: Make sure the network is configured. Note that it can take a minute for
880: the xnf0 interface to appear.
881:
1.4 mspo 882: opensolaris console login: jack
883: Password: jack
884: Sun Microsystems Inc. SunOS 5.11 snv_124 November 2008
885: jack@opensolaris:~$ pfexec sh
886: sh-3.2# ifconfig -a
887: sh-3.2# exit
1.5 mspo 888:
1.1 mspo 889:
890: Set a password for VNC and start the VNC server which provides the X11
891: display where the installation program runs.
892:
1.4 mspo 893: jack@opensolaris:~$ vncpasswd
894: Password: solaris
895: Verify: solaris
896: jack@opensolaris:~$ cp .Xclients .vnc/xstartup
897: jack@opensolaris:~$ vncserver :1
1.5 mspo 898:
1.1 mspo 899:
1.5 mspo 900: From a remote machine connect to the VNC server. Use `ifconfig xnf0` on
901: the guest to find the correct IP address to use.
1.1 mspo 902:
1.4 mspo 903: remote$ vncviewer 172.18.2.99:1
1.5 mspo 904:
1.1 mspo 905:
906: It is also possible to launch the installation on a remote X11 display.
907:
1.4 mspo 908: jack@opensolaris:~$ export DISPLAY=172.18.1.1:0
909: jack@opensolaris:~$ pfexec gui-install
1.5 mspo 910:
1.1 mspo 911:
912: After the GUI installation is complete you will be asked to reboot.
913: Before that you need to determine the ZFS ID for the new boot filesystem
914: and update the configuration file accordingly. Return to the guest
915: console.
916:
1.4 mspo 917: jack@opensolaris:~$ pfexec zdb -vvv rpool | grep bootfs
918: bootfs = 43
919: ^C
920: jack@opensolaris:~$
1.5 mspo 921:
1.1 mspo 922:
923: The final configuration file should look like this. Note in particular
924: the last line.
925:
1.4 mspo 926: memory = 640
927: name = 'solaris'
928: disk = [ 'phy:/dev/wd0k,0,w' ]
929: vif = [ 'bridge=bridge0' ]
930: kernel = '/root/solaris/unix'
931: ramdisk = '/root/solaris/x86.microroot'
932: extra = '/platform/i86xpv/kernel/amd64/unix -B zfs-bootfs=rpool/43,bootpath="/xpvd/xdf@0:a"'
1.5 mspo 933:
1.1 mspo 934:
935: Restart the guest to verify it works correctly.
936:
1.4 mspo 937: dom0# xm destroy solaris
938: dom0# xm create -c solaris.cfg
939: Using config file "./solaris.cfg".
940: v3.3.2 chgset 'unavailable'
941: Started domain solaris
942: SunOS Release 5.11 Version snv_124 64-bit
943: Copyright 1983-2009 Sun Microsystems, Inc. All rights reserved.
944: Use is subject to license terms.
945: WARNING: emlxs: ddi_modopen drv/fct failed: err 2
946: Hostname: osol
947: Configuring devices.
948: Loading smf(5) service descriptions: 160/160
949: svccfg import warnings. See /var/svc/log/system-manifest-import:default.log .
950: Reading ZFS config: done.
951: Mounting ZFS filesystems: (6/6)
952: Creating new rsa public/private host key pair
953: Creating new dsa public/private host key pair
1.5 mspo 954:
1.4 mspo 955: osol console login:
1.5 mspo 956:
1.1 mspo 957:
958: Using PCI devices in guest domains
1.14 gdt 959: ----------------------------------
1.1 mspo 960:
961: The domain0 can give other domains access to selected PCI devices. This
962: can allow, for example, a non-privileged domain to have access to a
963: physical network interface or disk controller. However, keep in mind
964: that giving a domain access to a PCI device most likely will give the
965: domain read/write access to the whole physical memory, as PCs don't have
966: an IOMMU to restrict memory access to DMA-capable device. Also, it's not
967: possible to export ISA devices to non-domain0 domains (which means that
968: the primary VGA adapter can't be exported. A guest domain trying to
969: access the VGA registers will panic).
970:
971: This functionality is only available in NetBSD-5.1 (and later) domain0
972: and domU. If the domain0 is NetBSD, it has to be running Xen 3.1, as
973: support has not been ported to later versions at this time.
974:
975: For a PCI device to be exported to a domU, is has to be attached to the
1.5 mspo 976: `pciback` driver in domain0. Devices passed to the domain0 via the
977: pciback.hide boot parameter will attach to `pciback` instead of the
978: usual driver. The list of devices is specified as `(bus:dev.func)`,
979: where bus and dev are 2-digit hexadecimal numbers, and func a
980: single-digit number:
1.1 mspo 981:
1.4 mspo 982: pciback.hide=(00:0a.0)(00:06.0)
1.1 mspo 983:
984: pciback devices should show up in the domain0's boot messages, and the
1.5 mspo 985: devices should be listed in the `/kern/xen/pci` directory.
1.1 mspo 986:
1.5 mspo 987: PCI devices to be exported to a domU are listed in the `pci` array of
988: the domU's config file, with the format `'0000:bus:dev.func'`
1.1 mspo 989:
1.4 mspo 990: pci = [ '0000:00:06.0', '0000:00:0a.0' ]
1.1 mspo 991:
1.5 mspo 992: In the domU an `xpci` device will show up, to which one or more pci
993: busses will attach. Then the PCI drivers will attach to PCI busses as
994: usual. Note that the default NetBSD DOMU kernels do not have `xpci` or
995: any PCI drivers built in by default; you have to build your own kernel
996: to use PCI devices in a domU. Here's a kernel config example:
1.1 mspo 997:
1.4 mspo 998: include "arch/i386/conf/XEN3_DOMU"
999: #include "arch/i386/conf/XENU" # in NetBSD 3.0
1.5 mspo 1000:
1.4 mspo 1001: # Add support for PCI busses to the XEN3_DOMU kernel
1002: xpci* at xenbus ?
1003: pci* at xpci ?
1.5 mspo 1004:
1.4 mspo 1005: # Now add PCI and related devices to be used by this domain
1006: # USB Controller and Devices
1.5 mspo 1007:
1.4 mspo 1008: # PCI USB controllers
1009: uhci* at pci? dev ? function ? # Universal Host Controller (Intel)
1.5 mspo 1010:
1.4 mspo 1011: # USB bus support
1012: usb* at uhci?
1.5 mspo 1013:
1.4 mspo 1014: # USB Hubs
1015: uhub* at usb?
1016: uhub* at uhub? port ? configuration ? interface ?
1.5 mspo 1017:
1.4 mspo 1018: # USB Mass Storage
1019: umass* at uhub? port ? configuration ? interface ?
1020: wd* at umass?
1021: # SCSI controllers
1022: ahc* at pci? dev ? function ? # Adaptec [23]94x, aic78x0 SCSI
1.5 mspo 1023:
1.4 mspo 1024: # SCSI bus support (for both ahc and umass)
1025: scsibus* at scsi?
1.5 mspo 1026:
1.4 mspo 1027: # SCSI devices
1028: sd* at scsibus? target ? lun ? # SCSI disk drives
1029: cd* at scsibus? target ? lun ? # SCSI CD-ROM drives
1.1 mspo 1030:
1031:
1.28 gdt 1032: NetBSD as a domU in a VPS
1033: =========================
1034:
1035: The bulk of the HOWTO is about using NetBSD as a dom0 on your own
1036: hardware. This section explains how to deal with Xen in a domU as a
1037: virtual private server where you do not control or have access to the
1038: dom0.
1039:
1040: TODO: Perhaps reference panix, prmgr, amazon as interesting examples.
1041:
1042: TODO: Somewhere, discuss pvgrub and py-grub to load the domU kernel
1043: from the domU filesystem.
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