Annotation of wikisrc/ports/xen/howto.mdwn, revision 1.45
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:
1.45 ! gdt 184: For experimenting with Xen, a machine with as little as 1G of RAM and
! 185: 100G of disk can work. For running many domUs in productions, far
! 186: more will be needed.
! 187:
1.15 gdt 188: Styles of dom0 operation
189: ------------------------
190:
191: There are two basic ways to use Xen. The traditional method is for
192: the dom0 to do absolutely nothing other than providing support to some
193: number of domUs. Such a system was probably installed for the sole
194: purpose of hosting domUs, and sits in a server room on a UPS.
195:
196: The other way is to put Xen under a normal-usage computer, so that the
197: dom0 is what the computer would have been without Xen, perhaps a
198: desktop or laptop. Then, one can run domUs at will. Purists will
199: deride this as less secure than the previous approach, and for a
200: computer whose purpose is to run domUs, they are right. But Xen and a
201: dom0 (without domUs) is not meaingfully less secure than the same
202: things running without Xen. One can boot Xen or boot regular NetBSD
203: alternately with little problems, simply refraining from starting the
204: Xen daemons when not running Xen.
205:
206: Note that NetBSD as dom0 does not support multiple CPUs. This will
207: limit the performance of the Xen/dom0 workstation approach.
208:
1.19 gdt 209: Installation of NetBSD
210: ----------------------
1.13 gdt 211:
1.19 gdt 212: First,
1.27 jnemeth 213: [install NetBSD/amd64](/guide/inst/)
1.19 gdt 214: just as you would if you were not using Xen.
215: However, the partitioning approach is very important.
216:
217: If you want to use RAIDframe for the dom0, there are no special issues
218: for Xen. Typically one provides RAID storage for the dom0, and the
1.22 gdt 219: domU systems are unaware of RAID. The 2nd-stage loader bootxx_* skips
220: over a RAID1 header to find /boot from a filesystem within a RAID
221: partition; this is no different when booting Xen.
1.19 gdt 222:
223: There are 4 styles of providing backing storage for the virtual disks
224: used by domUs: raw partitions, LVM, file-backed vnd(4), and SAN,
225:
226: With raw partitions, one has a disklabel (or gpt) partition sized for
227: each virtual disk to be used by the domU. (If you are able to predict
228: how domU usage will evolve, please add an explanation to the HOWTO.
229: Seriously, needs tend to change over time.)
230:
1.27 jnemeth 231: One can use [lvm(8)](/guide/lvm/) to create logical devices to use
232: for domU disks. This is almost as efficient as raw disk partitions
233: and more flexible. Hence raw disk partitions should typically not
234: be used.
1.19 gdt 235:
236: One can use files in the dom0 filesystem, typically created by dd'ing
237: /dev/zero to create a specific size. This is somewhat less efficient,
238: but very convenient, as one can cp the files for backup, or move them
239: between dom0 hosts.
240:
241: Finally, in theory one can place the files backing the domU disks in a
242: SAN. (This is an invitation for someone who has done this to add a
243: HOWTO page.)
1.1 mspo 244:
1.19 gdt 245: Installation of Xen
246: -------------------
1.1 mspo 247:
1.20 gdt 248: In the dom0, install sysutils/xenkernel42 and sysutils/xentools42 from
249: pkgsrc (or another matching pair).
250: See [the pkgsrc
251: documentation](http://www.NetBSD.org/docs/pkgsrc/) for help with pkgsrc.
252:
253: For Xen 3.1, support for HVM guests is in sysutils/xentool3-hvm. More
254: recent versions have HVM support integrated in the main xentools
255: package. It is entirely reasonable to run only PV guests.
256:
257: Next you need to install the selected Xen kernel itself, which is
258: installed by pkgsrc as "/usr/pkg/xen*-kernel/xen.gz". Copy it to /.
259: For debugging, one may copy xen-debug.gz; this is conceptually similar
260: to DIAGNOSTIC and DEBUG in NetBSD. xen-debug.gz is basically only
261: useful with a serial console. Then, place a NetBSD XEN3_DOM0 kernel
262: in /, copied from releasedir/amd64/binary/kernel/netbsd-XEN3_DOM0.gz
263: of a NetBSD build. Both xen and NetBSD may be left compressed. (If
264: using i386, use releasedir/i386/binary/kernel/netbsd-XEN3PAE_DOM0.gz.)
265:
266: In a dom0 kernel, kernfs is mandatory for xend to comunicate with the
267: kernel, so ensure that /kern is in fstab.
268:
269: Because you already installed NetBSD, you have a working boot setup
270: with an MBR bootblock, either bootxx_ffsv1 or bootxx_ffsv2 at the
271: beginning of your root filesystem, /boot present, and likely
272: /boot.cfg. (If not, fix before continuing!)
273:
274: See boot.cfg(5) for an example. The basic line is
275:
1.37 gdt 276: menu=Xen:load /netbsd-XEN3_DOM0.gz console=pc;multiboot /xen.gz dom0_mem=256M
1.20 gdt 277:
278: which specifies that the dom0 should have 256M, leaving the rest to be
1.37 gdt 279: allocated for domUs. In an attempt to add performance, one can also
280: add
281:
282: dom0_max_vcpus=1 dom0_vcpus_pin
283:
284: to force only one vcpu to be provided (since NetBSD dom0 can't use
285: more) and to pin that vcpu to a physical cpu. TODO: benchmark this.
1.20 gdt 286:
287: As with non-Xen systems, you should have a line to boot /netbsd (a
288: kernel that works without Xen) and fallback versions of the non-Xen
289: kernel, Xen, and the dom0 kernel.
1.1 mspo 290:
1.28 gdt 291: The [HowTo on Installing into
292: RAID-1](http://mail-index.NetBSD.org/port-xen/2006/03/01/0010.html)
293: explains how to set up booting a dom0 with Xen using grub with
294: NetBSD's RAIDframe. (This is obsolete with the use of NetBSD's native
295: boot.)
296:
1.21 gdt 297: Configuring Xen
298: ---------------
299:
300: Now, you have a system that will boot Xen and the dom0 kernel, and
301: just run the dom0 kernel. There will be no domUs, and none can be
1.31 gdt 302: started because you still have to configure the dom0 tools. The
303: daemons which should be run vary with Xen version and with whether one
304: is using xm or xl. Note that xend is for supporting "xm", and should
305: only be used if you plan on using "xm". Do NOT enable xend if you
306: plan on using "xl" as it will cause problems.
1.21 gdt 307:
1.43 gdt 308: The installation of NetBSD should already have created devices for xen
309: (xencons, xenevt), but if they are not present, create them:
310:
311: cd /dev && sh MAKEDEV xen
312:
1.31 gdt 313: TODO: Give 3.1 advice (or remove it from pkgsrc).
314:
315: For 3.3 (and thus xm), add to rc.conf (but note that you should have
316: installed 4.1 or 4.2):
317:
1.32 gdt 318: xend=YES
319: xenbackendd=YES
1.31 gdt 320:
1.33 gdt 321: For 4.1 (and thus xm; xl is believed not to work well), add to rc.conf:
1.31 gdt 322:
323: xend=YES
324: xencommons=YES
325:
326: TODO: Explain why if xm is preferred on 4.1, rc.d/xendomains has xl.
1.33 gdt 327: Or fix the package.
1.31 gdt 328:
1.33 gdt 329: For 4.2 with xm, add to rc.conf
330:
331: xend=YES
332: xencommons=YES
333:
334: For 4.2 with xl (preferred), add to rc.conf:
1.31 gdt 335:
336: TODO: explain if there is a xend replacement
337: xencommons=YES
338:
339: TODO: Recommend for/against xen-watchdog.
1.27 jnemeth 340:
1.43 gdt 341: After you have configured the daemons and either started them or
1.42 gdt 342: rebooted, run the following (or use xl) to inspect Xen's boot
343: messages, available resources, and running domains:
1.34 gdt 344:
1.43 gdt 345: # xm dmesg
346: [xen's boot info]
347: # xm info
348: [available memory, etc.]
349: # xm list
350: Name Id Mem(MB) CPU State Time(s) Console
351: Domain-0 0 64 0 r---- 58.1
1.33 gdt 352:
1.41 gdt 353: anita (for testing NetBSD)
354: --------------------------
355:
356: With the setup so far, one should be able to run anita (see
357: pkgsrc/sysutils/py-anita) to test NetBSD releases, by doing (as root,
358: because anita must create a domU):
359:
360: anita --vmm=xm test file:///usr/obj/i386/
361:
362: Alternatively, one can use --vmm=xl to use xl-based domU creation instead.
363: TODO: check this.
364:
1.40 gdt 365: Xen-specific NetBSD issues
366: --------------------------
367:
368: There are (at least) two additional things different about NetBSD as a
369: dom0 kernel compared to hardware.
370:
371: One is that modules are not usable in DOM0 kernels, so one must
372: compile in what's needed. It's not really that modules cannot work,
373: but that modules must be built for XEN3_DOM0 because some of the
374: defines change and the normal module builds don't do this. Basically,
375: enabling Xen changes the kernel ABI, and the module build system
376: doesn't cope with this.
377:
378: The other difference is that XEN3_DOM0 does not have exactly the same
379: options as GENERIC. While it is debatable whether or not this is a
380: bug, users should be aware of this and can simply add missing config
381: items if desired.
382:
1.15 gdt 383: Updating NetBSD in a dom0
384: -------------------------
385:
386: This is just like updating NetBSD on bare hardware, assuming the new
387: version supports the version of Xen you are running. Generally, one
388: replaces the kernel and reboots, and then overlays userland binaries
389: and adjusts /etc.
390:
391: Note that one must update both the non-Xen kernel typically used for
392: rescue purposes and the DOM0 kernel used with Xen.
393:
1.22 gdt 394: To convert from grub to /boot, install an mbr bootblock with fdisk,
395: bootxx_ with installboot, /boot and /boot.cfg. This really should be
396: no different than completely reinstalling boot blocks on a non-Xen
397: system.
398:
1.15 gdt 399: Updating Xen versions
400: ---------------------
401:
1.21 gdt 402: Updating Xen is conceptually not difficult, but can run into all the
403: issues found when installing Xen. Assuming migration from 4.1 to 4.2,
404: remove the xenkernel41 and xentools41 packages and install the
405: xenkernel42 and xentools42 packages. Copy the 4.2 xen.gz to /.
406:
407: Ensure that the contents of /etc/rc.d/xen* are correct. Enable the
408: correct set of daemons. Ensure that the domU config files are valid
409: for the new version.
1.15 gdt 410:
1.28 gdt 411:
412: Unprivileged domains (domU)
413: ===========================
414:
415: This section describes general concepts about domUs. It does not
1.33 gdt 416: address specific domU operating systems or how to install them. The
417: config files for domUs are typically in /usr/pkg/etc/xen, and are
418: typically named so that the file anme, domU name and the domU's host
419: name match.
420:
421: The domU is provided with cpu and memory by Xen, configured by the
422: dom0. The domU is provided with disk and network by the dom0,
423: mediated by Xen, and configured in the dom0.
424:
425: Entropy in domUs can be an issue; physical disks and network are on
426: the dom0. NetBSD's /dev/random system works, but is often challenged.
427:
428: CPU and memory
429: --------------
430:
431: A domain is provided with some number of vcpus, less than the
432: number of cpus seen by the hypervisor. For a dom0, this is controlled
433: by the boot argument "dom0_max_vcpus=1". For a domU, it is controlled
434: from the config file.
435:
436: A domain is provided with memory, In the straightforward case, the sum
437: of the the memory allocated to the dom0 and all domUs must be less
438: than the available memory.
439:
440: Xen also provides a "balloon" driver, which can be used to let domains
441: use more memory temporarily. TODO: Explain better, and explain how
442: well it works with NetBSD.
1.28 gdt 443:
444: Virtual disks
445: -------------
446:
1.33 gdt 447: With the file/vnd style, typically one creates a directory,
448: e.g. /u0/xen, on a disk large enough to hold virtual disks for all
449: domUs. Then, for each domU disk, one writes zeros to a file that then
450: serves to hold the virtual disk's bits; a suggested name is foo-xbd0
451: for the first virtual disk for the domU called foo. Writing zeros to
452: the file serves two purposes. One is that preallocating the contents
453: improves performance. The other is that vnd on sparse files has
454: failed to work. TODO: give working/notworking NetBSD versions for
455: sparse vnd. Note that the use of file/vnd for Xen is not really
456: different than creating a file-backed virtual disk for some other
1.39 gdt 457: purpose, except that xentools handles the vnconfig commands. To
458: create an empty 4G virtual disk, simply do
459:
460: dd if=/dev/zero of=foo-xbd0 bs=1m count=4096
1.33 gdt 461:
462: With the lvm style, one creates logical devices. They are then used
463: similarly to vnds.
1.28 gdt 464:
465: Virtual Networking
466: ------------------
467:
468: TODO: explain xvif concept, and that it's general.
469:
470: There are two normal styles: bridging and NAT.
471:
472: With bridging, the domU perceives itself to be on the same network as
473: the dom0. For server virtualization, this is usually best.
474:
475: With NAT, the domU perceives itself to be behind a NAT running on the
476: dom0. This is often appropriate when running Xen on a workstation.
477:
478: One can construct arbitrary other configurations, but there is no
479: script support.
480:
1.33 gdt 481: Sizing domains
482: --------------
483:
484: Modern x86 hardware has vast amounts of resources. However, many
485: virtual servers can function just fine on far less. A system with
486: 256M of RAM and a 4G disk can be a reasonable choice. Note that it is
487: far easier to adjust virtual resources than physical ones. For
488: memory, it's just a config file edit and a reboot. For disk, one can
489: create a new file and vnconfig it (or lvm), and then dump/restore,
490: just like updating physical disks, but without having to be there and
491: without those pesky connectors.
492:
1.39 gdt 493: domU kernels
494: ------------
495:
496: On a physical computer, the BIOS reads sector 0, and a chain of boot
497: loaders finds and loads a kernel. Normally this comes from the root
498: filesystem. With Xen domUs, the process is totally different. The
499: normal path is for the domU kernel to be a file in the dom0's
500: filesystem. At the request of the dom0, Xen loads that kernel into a
501: new domU instance and starts execution. While domU kernels can be
502: anyplace, reasonable places to store domU kernels on the dom0 are in /
503: (so they are near the dom0 kernel), in /usr/pkg/etc/xen (near the
504: config files), or in /u0/xen (where the vdisks are).
505:
506: See the VPS section near the end for discussion of alternate ways to
507: obtain domU kernels.
508:
1.28 gdt 509: Config files
510: ------------
511:
512: TODO: give example config files. Use both lvm and vnd.
513:
514: TODO: explain the mess with 3 arguments for disks and how to cope (0x1).
515:
516: Starting domains
517: ----------------
518:
519: TODO: Explain "xm start" and "xl start". Explain rc.d/xendomains.
520:
521: TODO: Explain why 4.1 rc.d/xendomains has xl, when one should use xm
522: on 4.1.
523:
524: Creating specific unprivileged domains (domU)
525: =============================================
1.14 gdt 526:
527: Creating domUs is almost entirely independent of operating system. We
528: first explain NetBSD, and then differences for Linux and Solaris.
1.43 gdt 529: Note that you must have already completed the dom0 setup so that "xm
530: list" (or "xl list") works.
1.14 gdt 531:
532: Creating an unprivileged NetBSD domain (domU)
533: ---------------------------------------------
1.1 mspo 534:
535: 'xm create' allows you to create a new domain. It uses a config file in
536: PKG\_SYSCONFDIR for its parameters. By default, this file will be in
1.5 mspo 537: `/usr/pkg/etc/xen/`. On creation, a kernel has to be specified, which
538: will be executed in the new domain (this kernel is in the *domain0* file
539: system, not on the new domain virtual disk; but please note, you should
540: install the same kernel into *domainU* as `/netbsd` in order to make
1.27 jnemeth 541: your system tools, like savecore(8), work). A suitable kernel is
1.5 mspo 542: provided as part of the i386 and amd64 binary sets: XEN3\_DOMU.
1.1 mspo 543:
544: Here is an /usr/pkg/etc/xen/nbsd example config file:
545:
1.3 mspo 546: # -*- mode: python; -*-
547: #============================================================================
548: # Python defaults setup for 'xm create'.
549: # Edit this file to reflect the configuration of your system.
550: #============================================================================
1.5 mspo 551:
1.3 mspo 552: #----------------------------------------------------------------------------
553: # Kernel image file. This kernel will be loaded in the new domain.
554: kernel = "/home/bouyer/netbsd-XEN3_DOMU"
555: #kernel = "/home/bouyer/netbsd-INSTALL_XEN3_DOMU"
1.5 mspo 556:
1.3 mspo 557: # Memory allocation (in megabytes) for the new domain.
558: memory = 128
1.5 mspo 559:
1.3 mspo 560: # A handy name for your new domain. This will appear in 'xm list',
561: # and you can use this as parameters for xm in place of the domain
562: # number. All domains must have different names.
563: #
564: name = "nbsd"
1.5 mspo 565:
1.3 mspo 566: # The number of virtual CPUs this domain has.
567: #
568: vcpus = 1
1.5 mspo 569:
1.3 mspo 570: #----------------------------------------------------------------------------
571: # Define network interfaces for the new domain.
1.5 mspo 572:
1.3 mspo 573: # Number of network interfaces (must be at least 1). Default is 1.
574: nics = 1
1.5 mspo 575:
1.3 mspo 576: # Define MAC and/or bridge for the network interfaces.
577: #
578: # The MAC address specified in ``mac'' is the one used for the interface
579: # in the new domain. The interface in domain0 will use this address XOR'd
580: # with 00:00:00:01:00:00 (i.e. aa:00:00:51:02:f0 in our example). Random
581: # MACs are assigned if not given.
582: #
583: # ``bridge'' is a required parameter, which will be passed to the
584: # vif-script called by xend(8) when a new domain is created to configure
585: # the new xvif interface in domain0.
586: #
587: # In this example, the xvif is added to bridge0, which should have been
588: # set up prior to the new domain being created -- either in the
589: # ``network'' script or using a /etc/ifconfig.bridge0 file.
590: #
591: vif = [ 'mac=aa:00:00:50:02:f0, bridge=bridge0' ]
1.5 mspo 592:
1.3 mspo 593: #----------------------------------------------------------------------------
594: # Define the disk devices you want the domain to have access to, and
595: # what you want them accessible as.
596: #
597: # Each disk entry is of the form:
598: #
1.5 mspo 599: # phy:DEV,VDEV,MODE
1.3 mspo 600: #
601: # where DEV is the device, VDEV is the device name the domain will see,
602: # and MODE is r for read-only, w for read-write. You can also create
603: # file-backed domains using disk entries of the form:
604: #
1.5 mspo 605: # file:PATH,VDEV,MODE
1.3 mspo 606: #
607: # where PATH is the path to the file used as the virtual disk, and VDEV
608: # and MODE have the same meaning as for ``phy'' devices.
609: #
610: # VDEV doesn't really matter for a NetBSD guest OS (it's just used as an index),
611: # but it does for Linux.
612: # Worse, the device has to exist in /dev/ of domain0, because xm will
613: # try to stat() it. This means that in order to load a Linux guest OS
614: # from a NetBSD domain0, you'll have to create /dev/hda1, /dev/hda2, ...
615: # on domain0, with the major/minor from Linux :(
616: # Alternatively it's possible to specify the device number in hex,
617: # e.g. 0x301 for /dev/hda1, 0x302 for /dev/hda2, etc ...
1.5 mspo 618:
1.3 mspo 619: disk = [ 'phy:/dev/wd0e,0x1,w' ]
620: #disk = [ 'file:/var/xen/nbsd-disk,0x01,w' ]
621: #disk = [ 'file:/var/xen/nbsd-disk,0x301,w' ]
1.5 mspo 622:
1.3 mspo 623: #----------------------------------------------------------------------------
624: # Set the kernel command line for the new domain.
1.5 mspo 625:
1.3 mspo 626: # Set root device. This one does matter for NetBSD
627: root = "xbd0"
628: # extra parameters passed to the kernel
629: # this is where you can set boot flags like -s, -a, etc ...
630: #extra = ""
1.5 mspo 631:
1.3 mspo 632: #----------------------------------------------------------------------------
633: # Set according to whether you want the domain restarted when it exits.
634: # The default is False.
635: #autorestart = True
1.5 mspo 636:
1.3 mspo 637: # end of nbsd config file ====================================================
1.1 mspo 638:
639: When a new domain is created, xen calls the
1.5 mspo 640: `/usr/pkg/etc/xen/vif-bridge` script for each virtual network interface
641: created in *domain0*. This can be used to automatically configure the
642: xvif?.? interfaces in *domain0*. In our example, these will be bridged
643: with the bridge0 device in *domain0*, but the bridge has to exist first.
644: To do this, create the file `/etc/ifconfig.bridge0` and make it look
645: like this:
1.1 mspo 646:
1.3 mspo 647: create
648: !brconfig $int add ex0 up
1.1 mspo 649:
1.5 mspo 650: (replace `ex0` with the name of your physical interface). Then bridge0
1.27 jnemeth 651: will be created on boot. See the bridge(4) man page for details.
1.1 mspo 652:
1.5 mspo 653: So, here is a suitable `/usr/pkg/etc/xen/vif-bridge` for xvif?.? (a
654: working vif-bridge is also provided with xentools20) configuring:
1.1 mspo 655:
1.5 mspo 656: #!/bin/sh
1.3 mspo 657: #============================================================================
1.45 ! gdt 658: # $NetBSD: howto.mdwn,v 1.44 2014/12/26 14:20:27 gdt Exp $
1.3 mspo 659: #
660: # /usr/pkg/etc/xen/vif-bridge
661: #
662: # Script for configuring a vif in bridged mode with a dom0 interface.
663: # The xend(8) daemon calls a vif script when bringing a vif up or down.
664: # The script name to use is defined in /usr/pkg/etc/xen/xend-config.sxp
665: # in the ``vif-script'' field.
666: #
667: # Usage: vif-bridge up|down [var=value ...]
668: #
669: # Actions:
1.5 mspo 670: # up Adds the vif interface to the bridge.
671: # down Removes the vif interface from the bridge.
1.3 mspo 672: #
673: # Variables:
1.5 mspo 674: # domain name of the domain the interface is on (required).
675: # vifq vif interface name (required).
676: # mac vif MAC address (required).
677: # bridge bridge to add the vif to (required).
1.3 mspo 678: #
679: # Example invocation:
680: #
681: # vif-bridge up domain=VM1 vif=xvif1.0 mac="ee:14:01:d0:ec:af" bridge=bridge0
682: #
683: #============================================================================
1.5 mspo 684:
1.3 mspo 685: # Exit if anything goes wrong
686: set -e
1.5 mspo 687:
1.3 mspo 688: echo "vif-bridge $*"
1.5 mspo 689:
1.3 mspo 690: # Operation name.
691: OP=$1; shift
1.5 mspo 692:
1.3 mspo 693: # Pull variables in args into environment
694: for arg ; do export "${arg}" ; done
1.5 mspo 695:
1.3 mspo 696: # Required parameters. Fail if not set.
697: domain=${domain:?}
698: vif=${vif:?}
699: mac=${mac:?}
700: bridge=${bridge:?}
1.5 mspo 701:
1.3 mspo 702: # Optional parameters. Set defaults.
703: ip=${ip:-''} # default to null (do nothing)
1.5 mspo 704:
1.3 mspo 705: # Are we going up or down?
706: case $OP in
1.5 mspo 707: up) brcmd='add' ;;
1.3 mspo 708: down) brcmd='delete' ;;
709: *)
1.5 mspo 710: echo 'Invalid command: ' $OP
711: echo 'Valid commands are: up, down'
712: exit 1
713: ;;
1.3 mspo 714: esac
1.5 mspo 715:
1.3 mspo 716: # Don't do anything if the bridge is "null".
717: if [ "${bridge}" = "null" ] ; then
1.5 mspo 718: exit
1.3 mspo 719: fi
1.5 mspo 720:
1.3 mspo 721: # Don't do anything if the bridge doesn't exist.
722: if ! ifconfig -l | grep "${bridge}" >/dev/null; then
1.5 mspo 723: exit
1.3 mspo 724: fi
1.5 mspo 725:
1.3 mspo 726: # Add/remove vif to/from bridge.
727: ifconfig x${vif} $OP
728: brconfig ${bridge} ${brcmd} x${vif}
1.1 mspo 729:
730: Now, running
731:
1.3 mspo 732: xm create -c /usr/pkg/etc/xen/nbsd
1.1 mspo 733:
1.5 mspo 734: should create a domain and load a NetBSD kernel in it. (Note: `-c`
735: causes xm to connect to the domain's console once created.) The kernel
736: will try to find its root file system on xbd0 (i.e., wd0e) which hasn't
737: been created yet. wd0e will be seen as a disk device in the new domain,
738: so it will be 'sub-partitioned'. We could attach a ccd to wd0e in
739: *domain0* and partition it, newfs and extract the NetBSD/i386 or amd64
740: tarballs there, but there's an easier way: load the
741: `netbsd-INSTALL_XEN3_DOMU` kernel provided in the NetBSD binary sets.
742: Like other install kernels, it contains a ramdisk with sysinst, so you
743: can install NetBSD using sysinst on your new domain.
1.1 mspo 744:
745: If you want to install NetBSD/Xen with a CDROM image, the following line
1.5 mspo 746: should be used in the `/usr/pkg/etc/xen/nbsd` file:
1.1 mspo 747:
1.3 mspo 748: disk = [ 'phy:/dev/wd0e,0x1,w', 'phy:/dev/cd0a,0x2,r' ]
1.1 mspo 749:
750: After booting the domain, the option to install via CDROM may be
1.5 mspo 751: selected. The CDROM device should be changed to `xbd1d`.
1.1 mspo 752:
1.5 mspo 753: Once done installing, `halt -p` the new domain (don't reboot or halt, it
754: would reload the INSTALL\_XEN3\_DOMU kernel even if you changed the
1.1 mspo 755: config file), switch the config file back to the XEN3\_DOMU kernel, and
1.5 mspo 756: start the new domain again. Now it should be able to use `root on xbd0a`
757: and you should have a second, functional NetBSD system on your xen
758: installation.
1.1 mspo 759:
760: When the new domain is booting you'll see some warnings about *wscons*
761: and the pseudo-terminals. These can be fixed by editing the files
1.5 mspo 762: `/etc/ttys` and `/etc/wscons.conf`. You must disable all terminals in
763: `/etc/ttys`, except *console*, like this:
1.1 mspo 764:
1.3 mspo 765: console "/usr/libexec/getty Pc" vt100 on secure
766: ttyE0 "/usr/libexec/getty Pc" vt220 off secure
767: ttyE1 "/usr/libexec/getty Pc" vt220 off secure
768: ttyE2 "/usr/libexec/getty Pc" vt220 off secure
769: ttyE3 "/usr/libexec/getty Pc" vt220 off secure
1.1 mspo 770:
1.5 mspo 771: Finally, all screens must be commented out from `/etc/wscons.conf`.
1.1 mspo 772:
773: It is also desirable to add
774:
1.3 mspo 775: powerd=YES
1.1 mspo 776:
1.5 mspo 777: in rc.conf. This way, the domain will be properly shut down if
778: `xm shutdown -R` or `xm shutdown -H` is used on the domain0.
1.1 mspo 779:
780: Your domain should be now ready to work, enjoy.
781:
1.14 gdt 782: Creating an unprivileged Linux domain (domU)
1.5 mspo 783: --------------------------------------------
1.1 mspo 784:
785: Creating unprivileged Linux domains isn't much different from
786: unprivileged NetBSD domains, but there are some details to know.
787:
788: First, the second parameter passed to the disk declaration (the '0x1' in
789: the example below)
790:
1.3 mspo 791: disk = [ 'phy:/dev/wd0e,0x1,w' ]
1.1 mspo 792:
793: does matter to Linux. It wants a Linux device number here (e.g. 0x300
794: for hda). Linux builds device numbers as: (major \<\< 8 + minor). So,
795: hda1 which has major 3 and minor 1 on a Linux system will have device
796: number 0x301. Alternatively, devices names can be used (hda, hdb, ...)
797: as xentools has a table to map these names to devices numbers. To export
798: a partition to a Linux guest we can use:
799:
1.3 mspo 800: disk = [ 'phy:/dev/wd0e,0x300,w' ]
801: root = "/dev/hda1 ro"
1.1 mspo 802:
803: and it will appear as /dev/hda on the Linux system, and be used as root
804: partition.
805:
806: To install the Linux system on the partition to be exported to the guest
807: domain, the following method can be used: install sysutils/e2fsprogs
808: from pkgsrc. Use mke2fs to format the partition that will be the root
809: partition of your Linux domain, and mount it. Then copy the files from a
1.5 mspo 810: working Linux system, make adjustments in `/etc` (fstab, network
811: config). It should also be possible to extract binary packages such as
812: .rpm or .deb directly to the mounted partition using the appropriate
813: tool, possibly running under NetBSD's Linux emulation. Once the
814: filesystem has been populated, umount it. If desirable, the filesystem
815: can be converted to ext3 using tune2fs -j. It should now be possible to
816: boot the Linux guest domain, using one of the vmlinuz-\*-xenU kernels
817: available in the Xen binary distribution.
1.1 mspo 818:
819: To get the linux console right, you need to add:
820:
1.3 mspo 821: extra = "xencons=tty1"
1.1 mspo 822:
823: to your configuration since not all linux distributions auto-attach a
824: tty to the xen console.
825:
1.14 gdt 826: Creating an unprivileged Solaris domain (domU)
1.5 mspo 827: ----------------------------------------------
1.1 mspo 828:
829: Download an Opensolaris [release](http://opensolaris.org/os/downloads/)
830: or [development snapshot](http://genunix.org/) DVD image. Attach the DVD
1.5 mspo 831: image to a MAN.VND.4 device. Copy the kernel and ramdisk filesystem
832: image to your dom0 filesystem.
1.1 mspo 833:
1.3 mspo 834: dom0# mkdir /root/solaris
835: dom0# vnconfig vnd0 osol-1002-124-x86.iso
836: dom0# mount /dev/vnd0a /mnt
1.5 mspo 837:
1.3 mspo 838: ## for a 64-bit guest
839: dom0# cp /mnt/boot/amd64/x86.microroot /root/solaris
840: dom0# cp /mnt/platform/i86xpv/kernel/amd64/unix /root/solaris
1.5 mspo 841:
1.3 mspo 842: ## for a 32-bit guest
843: dom0# cp /mnt/boot/x86.microroot /root/solaris
844: dom0# cp /mnt/platform/i86xpv/kernel/unix /root/solaris
1.5 mspo 845:
1.3 mspo 846: dom0# umount /mnt
1.5 mspo 847:
848:
849: Keep the MAN.VND.4 configured. For some reason the boot process stalls
850: unless the DVD image is attached to the guest as a "phy" device. Create
851: an initial configuration file with the following contents. Substitute
852: */dev/wd0k* with an empty partition at least 8 GB large.
1.1 mspo 853:
1.4 mspo 854: memory = 640
855: name = 'solaris'
856: disk = [ 'phy:/dev/wd0k,0,w' ]
857: disk += [ 'phy:/dev/vnd0d,6:cdrom,r' ]
858: vif = [ 'bridge=bridge0' ]
859: kernel = '/root/solaris/unix'
860: ramdisk = '/root/solaris/x86.microroot'
861: # for a 64-bit guest
862: extra = '/platform/i86xpv/kernel/amd64/unix - nowin -B install_media=cdrom'
863: # for a 32-bit guest
864: #extra = '/platform/i86xpv/kernel/unix - nowin -B install_media=cdrom'
1.5 mspo 865:
866:
1.1 mspo 867: Start the guest.
868:
1.4 mspo 869: dom0# xm create -c solaris.cfg
870: Started domain solaris
871: v3.3.2 chgset 'unavailable'
872: SunOS Release 5.11 Version snv_124 64-bit
873: Copyright 1983-2009 Sun Microsystems, Inc. All rights reserved.
874: Use is subject to license terms.
875: Hostname: opensolaris
876: Remounting root read/write
877: Probing for device nodes ...
878: WARNING: emlxs: ddi_modopen drv/fct failed: err 2
879: Preparing live image for use
880: Done mounting Live image
1.5 mspo 881:
1.1 mspo 882:
883: Make sure the network is configured. Note that it can take a minute for
884: the xnf0 interface to appear.
885:
1.4 mspo 886: opensolaris console login: jack
887: Password: jack
888: Sun Microsystems Inc. SunOS 5.11 snv_124 November 2008
889: jack@opensolaris:~$ pfexec sh
890: sh-3.2# ifconfig -a
891: sh-3.2# exit
1.5 mspo 892:
1.1 mspo 893:
894: Set a password for VNC and start the VNC server which provides the X11
895: display where the installation program runs.
896:
1.4 mspo 897: jack@opensolaris:~$ vncpasswd
898: Password: solaris
899: Verify: solaris
900: jack@opensolaris:~$ cp .Xclients .vnc/xstartup
901: jack@opensolaris:~$ vncserver :1
1.5 mspo 902:
1.1 mspo 903:
1.5 mspo 904: From a remote machine connect to the VNC server. Use `ifconfig xnf0` on
905: the guest to find the correct IP address to use.
1.1 mspo 906:
1.4 mspo 907: remote$ vncviewer 172.18.2.99:1
1.5 mspo 908:
1.1 mspo 909:
910: It is also possible to launch the installation on a remote X11 display.
911:
1.4 mspo 912: jack@opensolaris:~$ export DISPLAY=172.18.1.1:0
913: jack@opensolaris:~$ pfexec gui-install
1.5 mspo 914:
1.1 mspo 915:
916: After the GUI installation is complete you will be asked to reboot.
917: Before that you need to determine the ZFS ID for the new boot filesystem
918: and update the configuration file accordingly. Return to the guest
919: console.
920:
1.4 mspo 921: jack@opensolaris:~$ pfexec zdb -vvv rpool | grep bootfs
922: bootfs = 43
923: ^C
924: jack@opensolaris:~$
1.5 mspo 925:
1.1 mspo 926:
927: The final configuration file should look like this. Note in particular
928: the last line.
929:
1.4 mspo 930: memory = 640
931: name = 'solaris'
932: disk = [ 'phy:/dev/wd0k,0,w' ]
933: vif = [ 'bridge=bridge0' ]
934: kernel = '/root/solaris/unix'
935: ramdisk = '/root/solaris/x86.microroot'
936: extra = '/platform/i86xpv/kernel/amd64/unix -B zfs-bootfs=rpool/43,bootpath="/xpvd/xdf@0:a"'
1.5 mspo 937:
1.1 mspo 938:
939: Restart the guest to verify it works correctly.
940:
1.4 mspo 941: dom0# xm destroy solaris
942: dom0# xm create -c solaris.cfg
943: Using config file "./solaris.cfg".
944: v3.3.2 chgset 'unavailable'
945: Started domain solaris
946: SunOS Release 5.11 Version snv_124 64-bit
947: Copyright 1983-2009 Sun Microsystems, Inc. All rights reserved.
948: Use is subject to license terms.
949: WARNING: emlxs: ddi_modopen drv/fct failed: err 2
950: Hostname: osol
951: Configuring devices.
952: Loading smf(5) service descriptions: 160/160
953: svccfg import warnings. See /var/svc/log/system-manifest-import:default.log .
954: Reading ZFS config: done.
955: Mounting ZFS filesystems: (6/6)
956: Creating new rsa public/private host key pair
957: Creating new dsa public/private host key pair
1.5 mspo 958:
1.4 mspo 959: osol console login:
1.5 mspo 960:
1.1 mspo 961:
962: Using PCI devices in guest domains
1.14 gdt 963: ----------------------------------
1.1 mspo 964:
965: The domain0 can give other domains access to selected PCI devices. This
966: can allow, for example, a non-privileged domain to have access to a
967: physical network interface or disk controller. However, keep in mind
968: that giving a domain access to a PCI device most likely will give the
969: domain read/write access to the whole physical memory, as PCs don't have
970: an IOMMU to restrict memory access to DMA-capable device. Also, it's not
971: possible to export ISA devices to non-domain0 domains (which means that
972: the primary VGA adapter can't be exported. A guest domain trying to
973: access the VGA registers will panic).
974:
975: This functionality is only available in NetBSD-5.1 (and later) domain0
976: and domU. If the domain0 is NetBSD, it has to be running Xen 3.1, as
977: support has not been ported to later versions at this time.
978:
979: For a PCI device to be exported to a domU, is has to be attached to the
1.5 mspo 980: `pciback` driver in domain0. Devices passed to the domain0 via the
981: pciback.hide boot parameter will attach to `pciback` instead of the
982: usual driver. The list of devices is specified as `(bus:dev.func)`,
983: where bus and dev are 2-digit hexadecimal numbers, and func a
984: single-digit number:
1.1 mspo 985:
1.4 mspo 986: pciback.hide=(00:0a.0)(00:06.0)
1.1 mspo 987:
988: pciback devices should show up in the domain0's boot messages, and the
1.5 mspo 989: devices should be listed in the `/kern/xen/pci` directory.
1.1 mspo 990:
1.5 mspo 991: PCI devices to be exported to a domU are listed in the `pci` array of
992: the domU's config file, with the format `'0000:bus:dev.func'`
1.1 mspo 993:
1.4 mspo 994: pci = [ '0000:00:06.0', '0000:00:0a.0' ]
1.1 mspo 995:
1.5 mspo 996: In the domU an `xpci` device will show up, to which one or more pci
997: busses will attach. Then the PCI drivers will attach to PCI busses as
998: usual. Note that the default NetBSD DOMU kernels do not have `xpci` or
999: any PCI drivers built in by default; you have to build your own kernel
1000: to use PCI devices in a domU. Here's a kernel config example:
1.1 mspo 1001:
1.4 mspo 1002: include "arch/i386/conf/XEN3_DOMU"
1003: #include "arch/i386/conf/XENU" # in NetBSD 3.0
1.5 mspo 1004:
1.4 mspo 1005: # Add support for PCI busses to the XEN3_DOMU kernel
1006: xpci* at xenbus ?
1007: pci* at xpci ?
1.5 mspo 1008:
1.4 mspo 1009: # Now add PCI and related devices to be used by this domain
1010: # USB Controller and Devices
1.5 mspo 1011:
1.4 mspo 1012: # PCI USB controllers
1013: uhci* at pci? dev ? function ? # Universal Host Controller (Intel)
1.5 mspo 1014:
1.4 mspo 1015: # USB bus support
1016: usb* at uhci?
1.5 mspo 1017:
1.4 mspo 1018: # USB Hubs
1019: uhub* at usb?
1020: uhub* at uhub? port ? configuration ? interface ?
1.5 mspo 1021:
1.4 mspo 1022: # USB Mass Storage
1023: umass* at uhub? port ? configuration ? interface ?
1024: wd* at umass?
1025: # SCSI controllers
1026: ahc* at pci? dev ? function ? # Adaptec [23]94x, aic78x0 SCSI
1.5 mspo 1027:
1.4 mspo 1028: # SCSI bus support (for both ahc and umass)
1029: scsibus* at scsi?
1.5 mspo 1030:
1.4 mspo 1031: # SCSI devices
1032: sd* at scsibus? target ? lun ? # SCSI disk drives
1033: cd* at scsibus? target ? lun ? # SCSI CD-ROM drives
1.1 mspo 1034:
1035:
1.28 gdt 1036: NetBSD as a domU in a VPS
1037: =========================
1038:
1039: The bulk of the HOWTO is about using NetBSD as a dom0 on your own
1040: hardware. This section explains how to deal with Xen in a domU as a
1041: virtual private server where you do not control or have access to the
1042: dom0.
1043:
1044: TODO: Perhaps reference panix, prmgr, amazon as interesting examples.
1045:
1046: TODO: Somewhere, discuss pvgrub and py-grub to load the domU kernel
1047: from the domU filesystem.
1.44 gdt 1048:
1049: Using npf
1050: ---------
1051:
1052: In standard kernels, npf is a module, and thus cannot be loadeed in a
1053: DOMU kernel.
1054:
1055: TODO: explain how to compile npf into a custom kernel, answering:
1056: http://mail-index.netbsd.org/netbsd-users/2014/12/26/msg015576.html
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