Diff for /wikisrc/ports/xen/howto.mdwn between versions 1.135 and 1.147

version 1.135, 2016/12/21 16:57:10 version 1.147, 2018/07/26 10:47:25
Line 1 Line 1
   [[!meta title="Xen HowTo"]]
   
 Introduction  Introduction
 ============  ============
   
 [![[Xen  [![[Xen
 screenshot]](http://www.netbsd.org/gallery/in-Action/hubertf-xens.png)](http://www.netbsd.org/gallery/in-Action/hubertf-xen.png)  screenshot]](https://www.netbsd.org/gallery/in-Action/hubertf-xens.png)](https://www.netbsd.org/gallery/in-Action/hubertf-xen.png)
   
 Xen is a hypervisor (or virtual machine monitor) for x86 hardware  Xen is a hypervisor (or virtual machine monitor) for x86 hardware
 (i686-class or higher), which supports running multiple guest  (i686-class or higher), which supports running multiple guest
Line 51  attempts to address both the case of run Line 53  attempts to address both the case of run
 and running domUs under it (NetBSD and other), and also running NetBSD  and running domUs under it (NetBSD and other), and also running NetBSD
 as a domU in a VPS.  as a domU in a VPS.
   
 Xen 3.1 in pkgsrc supports "PCI passthrough", which means that  Xen 3.1 in pkgsrc used to support "PCI passthrough", which means that
 specific PCI devices can be made available to a specific domU instead  specific PCI devices can be made available to a specific domU instead
 of the dom0.  This can be useful to let a domU run X11, or access some  of the dom0.  This can be useful to let a domU run X11, or access some
 network interface or other peripheral.  network interface or other peripheral.
Line 86  hardware architecture on which it runs.  Line 88  hardware architecture on which it runs. 
 both Intel and AMD, and in 2016 a normal PC has this CPU  both Intel and AMD, and in 2016 a normal PC has this CPU
 architecture.)  architecture.)
   
 Xen  Xen versions
 ---  ------------
   
 In NetBSD, Xen is provided in pkgsrc, via matching pairs of packages  In NetBSD, Xen is provided in pkgsrc, via matching pairs of packages
 xenkernel and xentools.  We will refer only to the kernel versions,  xenkernel and xentools.  We will refer only to the kernel versions,
 but note that both packages must be installed together and must have  but note that both packages must be installed together and must have
 matching versions.  matching versions.
   
 xenkernel3 provides Xen 3.1.  It is no longer maintained by Xen, and  Versions available in pkgsrc:
 the last applied security patch was in 2011. Thus, it should not be  
 used.  It supports PCI passthrough, which is why people use it anyway.  
 Xen 3.1 runs on i386 (both non-PAE and PAE) and amd64 hardware.  
   
 xenkernel33 provides Xen 3.3.  It is no longer maintained by Xen, and  
 the last applied security patch was in 2012.  Thus, it should not be  
 used.  Xen 3.3 runs on i386 PAE and amd64 hardware.  There are no good  
 reasons to run this version.  
   
 xenkernel41 provides Xen 4.1.  It is no longer maintained by Xen, but  
 as of 2016-12 received backported security patches.  Xen 4.1 runs on  
 i386 PAE and amd64 hardware.  There are no good reasons to run this  
 version.  
   
 xenkernel42 provides Xen 4.2.  It is no longer maintained by Xen, but  
 as of 2016-12 received backported security patches.  Xen 4.2 runs on  
 i386 PAE and amd64 hardware.  The only reason to run this is if you  
 need to use xm instead of xl, or if you need to run on hardware that  
 supports i386 but not amd64.  (This might also be useful if you need  
 an i386 dom0, if it turns out that an amd64 Xen kernel and an i386  
 dom0 is problematic.)  
   
 xenkernel45 provides Xen 4.5.  As of 2016-12, security patches were  
 released by Xen and applied to pkgsrc.  Xen 4.5 runs on amd64 hardware  
 only.  While slightly old, 4.5 has been tested and run by others, so  
 it is the conservative choice.  
   
 xenkernel46 provides Xen 4.6.  It is new to pkgsrc as of 2016-05.  As  
 of 2016-12, security patches were released by Xen and applied to  
 pkgsrc.  Xen 4.6 runs on amd64 hardware only For new installations,  
 4.6 is probably the appropriate choice and it will likely soon be the  
 standard approach.  
   
 Xen 4.7 (released 2016-06) and 4.8 (released 2016-12) are not yet in  [[!table data="""
 pkgsrc.  Xen Version     |Package Name   |Xen CPU Support        |EOL'ed By Upstream
   4.2             |xenkernel42    |32bit, 64bit           |Yes
   4.5             |xenkernel45    |64bit                  |Yes
   4.6             |xenkernel46    |64bit                  |Partially
   4.8             |xenkernel48    |64bit                  |No
   4.11            |xenkernel411   |64bit                  |No
   """]]
   
 See also the [Xen Security Advisory page](http://xenbits.xen.org/xsa/).  See also the [Xen Security Advisory page](http://xenbits.xen.org/xsa/).
   
 Note that NetBSD support is called XEN3.  It works with Xen 3 and Xen  Note: Xen 4.2 was the last version to support 32bit CPUs.
 4 because the hypercall interface has been stable.  
   
 Xen command program  Xen command program
 -------------------  -------------------
Line 147  xm and xl work fine.  4.4 is the last ve Line 122  xm and xl work fine.  4.4 is the last ve
 You must make a global choice to use xm or xl, because it affects not  You must make a global choice to use xm or xl, because it affects not
 only which command you use, but the command used by rc.d scripts  only which command you use, but the command used by rc.d scripts
 (specifically xendomains) and which daemons should be run.  The  (specifically xendomains) and which daemons should be run.  The
 xentools packages provide xm for 3.1, 3.3 and 4.1 and xl for 4.2 and up.  xentools packages provide xl for 4.2 and up.
   
 In 4.2, you can choose to use xm by simply changing the ctl_command  In 4.2, you can choose to use xm by simply changing the ctl_command
 variable and setting xend=YES in rc.conf.  variable and setting xend=YES in rc.conf.
Line 160  xbd, where a vnd must be allocated).  Bu Line 135  xbd, where a vnd must be allocated).  Bu
 been adequately tested for a complex custom setup with a large number  been adequately tested for a complex custom setup with a large number
 of interfaces.  of interfaces.
   
 NetBSD  NetBSD versions
 ------  ---------------
   
 The netbsd-6, netbsd-7, and -current branches are all reasonable  The netbsd-7, netbsd-8, and -current branches are all reasonable
 choices, with more or less the same considerations for non-Xen use.  choices, with more or less the same considerations for non-Xen use.
 Therefore, netbsd-7 is recommended as the stable version of the most  NetBSD 8 is recommended as the stable version of the most recent
 recent release for production use.  In addition, netbsd-7 and -current  release for production use.
 have a important scheduler fix (in November of 2015) affecting  
 contention between dom0 and domUs; see  For developing Xen, netbsd-current may be appropriate.
 https://releng.netbsd.org/cgi-bin/req-7.cgi?show=1040 for a  
 description.  For those wanting to learn Xen or without production  
 stability concerns, netbsd-7 is still likely most appropriate, but  
 -current is also a reasonable choice.  (Xen runs ok on netbsd-5, but  
 the xentools packages are likely difficult to build, and netbsd-5 is  
 not supported.)  
   
 As of NetBSD 6, a NetBSD domU will support multiple vcpus.  There is  As of NetBSD 6, a NetBSD domU will support multiple vcpus.  There is
 no SMP support for NetBSD as dom0.  (The dom0 itself doesn't really  no SMP support for NetBSD as dom0.  (The dom0 itself doesn't really
 need SMP for dom0 functions; the lack of support is really a problem  need SMP for dom0 functions; the lack of support is really a problem
 when using a dom0 as a normal computer.)  when using a dom0 as a normal computer.)
   
   Note: NetBSD support is called XEN3. However, it does support Xen 4,
   because the hypercall interface has remained identical.
   
 Architecture  Architecture
 ------------  ------------
   
Line 225  NetBSD.  TODO: Include link to benchmark Line 197  NetBSD.  TODO: Include link to benchmark
 Stability  Stability
 ---------  ---------
   
 Mostly, NetBSD as a dom0 or domU is quite stable.  Mostly, NetBSD as a dom0 or domU is quite stable. However, just like every
 However, there are some open PRs indicating problems.  other architecture, there are some open PRs indicating problems.
   
  - [PR 48125](http://gnats.netbsd.org/48125)  
  - [PR 47720](http://gnats.netbsd.org/47720)  
   
 Note also that there are issues with sparse vnd(4) instances, but  Note also that there are issues with sparse vnd(4) instances, but
 these are not about Xen -- they just are noticed with sparse vnd(4)  these are not about Xen -- they just are noticed with sparse vnd(4)
Line 238  instances in support of virtual disks in Line 207  instances in support of virtual disks in
 Recommendation  Recommendation
 --------------  --------------
   
 Therefore, this HOWTO recommends running xenkernel45 or xenkernel46,  Therefore, this HOWTO recommends running xenkernel46, xl, the NetBSD 7
 xl, the NetBSD 7 stable branch, and to use an amd64 kernel as the  stable branch, and therefore to use an amd64 kernel as the dom0.
 dom0.  Either the i386PAE or amd64 version of NetBSD may be used as  Either the i386PAE or amd64 version of NetBSD may be used as domUs.
 domUs.  
   A tentative replacement recommendation is xenkernel48, xl, and NetBSD
 Status  8.
 ------  
   Because bugs are fixed quite often, and because of Xen security
 Ideally, all versions of Xen in pkgsrc would build on all supported  advisories, it is good to stay up to date with NetBSD (tracking a
 versions of NetBSD/amd64, to the point where this section would be  stable branch), with the Xen kernel (tracking a Xen version via
 silly.  However, that has not always been the case.  Besides aging  pkgsrc), and with the Xen tools.  Specifically, NetBSD (-7 and
 code and aging compilers, qemu (included in xentools for HVM support)  -current) got an important fix affecting dom0/domU timesharing in
 is difficult to build.  Note that there is intentionally no data for  November, 2015, and xentools46 got a fix to enable Ubuntu guests to
 4.5+ up for i386, and often omits xentools info if the corresponding  boot in December, 2016.
 kernel fails.  
   
 The following table gives status, with the date last checked  
 (generally on the most recent quarterly branch).  The first code is  
 "builds" if it builds ok, and "FAIL" for a failure to build.  The  
 second code/date only appears for xenkernel* and is "works" if it runs  
 ok as a dom0 and can support a domU, and "FAIL" if it won't boot or  
 run a domU.  
   
         xenkernel3 netbsd-6 i386 FAIL 201612  
         xenkernel33 netbsd-6 i386 FAIL 201612  
         xenkernel41 netbsd-6 i386 builds 201612  
         xenkernel42 netbsd-6 i386 builds 201612  
         xentools3 netbsd-6 i386 FAIL 201612  
         xentools33 netbsd-6 i386 FAIL 201612  
         xentools41 netbsd-6 i386 builds 201612  
         xentools42 netbsd-6 i386 FAIL 201612  
   
         xenkernel3 netbsd-7 i386 FAIL 201412  
         xenkernel33 netbsd-7 i386 FAIL 201412  
         xenkernel41 netbsd-7 i386 builds 201412  
         xenkernel42 netbsd-7 i386 builds 201412  
         xentools41 netbsd-7 i386 builds 201412  
         xentools42 netbsd-7 i386 ??FAIL 201412  
   
         xenkernel3 netbsd-6 amd64 FAIL 201612  
         xenkernel33 netbsd-6 amd64 FAIL 201612  
         xenkernel41 netbsd-6 amd64 builds 201612 works 201612  
         xenkernel42 netbsd-6 amd64 builds 201612 works 201612  
         xenkernel45 netbsd-6 amd64 builds 201612  
         xenkernel46 netbsd-6 amd64 builds 201612  
         xentools41 netbsd-6 amd64 builds 201612  
         xentools42 netbsd-6 amd64 builds 201612  
         xentools45 netbsd-6 amd64 builds 201612  
         xentools46 netbsd-6 amd64 FAIL 201612  
   
         xenkernel3 netbsd-7 amd64 builds 201612  
         xenkernel33 netbsd-7 amd64 builds 201612  
         xenkernel41 netbsd-7 amd64 builds 201612  
         xenkernel42 netbsd-7 amd64 builds 201612  
         xenkernel45 netbsd-7 amd64 builds 201612  
         xenkernel46 netbsd-7 amd64 builds 201612  
         xentools3 netbsd-7 amd64 builds 201612  
         xentools3-hvm netbsd-7 amd64 builds 201612  
         xentools33 netbsd-7 amd64 FAIL 201612  
         xentools41 netbsd-7 amd64 builds 201612  
         xentools42 netbsd-7 amd64 builds 201612  
         xentools45 netbsd-7 amd64 builds 201612  
         xentools46 netbsd-7 amd64 builds 201612  
   
 NetBSD as a dom0  NetBSD as a dom0
 ================  ================
Line 320  half-dozen domUs of 512M and 32G each.   Line 240  half-dozen domUs of 512M and 32G each.  
 have to be bigger than the sum of the RAM/disk needs of the dom0 and  have to be bigger than the sum of the RAM/disk needs of the dom0 and
 all the domUs.  all the domUs.
   
   In 2018-05, trouble booting a dom0 was reported with 256M of RAM: with
   512M it worked reliably.  This does not make sense, but if you see
   "not ELF" after Xen boots, try increasing dom0 RAM.
   
 Styles of dom0 operation  Styles of dom0 operation
 ------------------------  ------------------------
   
Line 341  Xen daemons when not running Xen. Line 265  Xen daemons when not running Xen.
 Note that NetBSD as dom0 does not support multiple CPUs.  This will  Note that NetBSD as dom0 does not support multiple CPUs.  This will
 limit the performance of the Xen/dom0 workstation approach.  In theory  limit the performance of the Xen/dom0 workstation approach.  In theory
 the only issue is that the "backend drivers" are not yet MPSAFE:  the only issue is that the "backend drivers" are not yet MPSAFE:
   http://mail-index.netbsd.org/netbsd-users/2014/08/29/msg015195.html    https://mail-index.netbsd.org/netbsd-users/2014/08/29/msg015195.html
   
 Installation of NetBSD  Installation of NetBSD
 ----------------------  ----------------------
Line 384  Installation of Xen Line 308  Installation of Xen
   
 In the dom0, install sysutils/xenkernel42 and sysutils/xentools42 from  In the dom0, install sysutils/xenkernel42 and sysutils/xentools42 from
 pkgsrc (or another matching pair).  See [the pkgsrc  pkgsrc (or another matching pair).  See [the pkgsrc
 documentation](http://www.NetBSD.org/docs/pkgsrc/) for help with  documentation](https://www.NetBSD.org/docs/pkgsrc/) for help with
 pkgsrc.  Ensure that your packages are recent; the HOWTO does not  pkgsrc.  Ensure that your packages are recent; the HOWTO does not
 contemplate old builds.  contemplate old builds.
   
Line 417  beginning of your root file system, have Line 341  beginning of your root file system, have
 Add a line to to /boot.cfg to boot Xen.  See boot.cfg(5) for an  Add a line to to /boot.cfg to boot Xen.  See boot.cfg(5) for an
 example.  The basic line is  example.  The basic line is
   
         menu=Xen:load /netbsd-XEN3_DOM0.gz console=pc;multiboot /xen.gz dom0_mem=256M          menu=Xen:load /netbsd-XEN3_DOM0.gz console=pc;multiboot /xen.gz dom0_mem=512M
   
 which specifies that the dom0 should have 256M, leaving the rest to be  which specifies that the dom0 should have 512M, leaving the rest to be
 allocated for domUs.  To use a serial console, use  allocated for domUs.  To use a serial console, use
   
         menu=Xen:load /netbsd-XEN3_DOM0.gz console=com0;multiboot /xen.gz dom0_mem=256M console=com1 com1=9600,8n1          menu=Xen:load /netbsd-XEN3_DOM0.gz;multiboot /xen.gz dom0_mem=512M console=com1 com1=9600,8n1
   
 which will use the first serial port for Xen (which counts starting  which will use the first serial port for Xen (which counts starting
 from 1), forcing speed/parity, and also for NetBSD (which counts  from 1, unlike NetBSD which counts starting from 0), forcing
 starting at 0).  In an attempt to add performance, one can also add  speed/parity.  Because the NetBSD command line lacks a
   "console=pc" argument, it will use the default "xencons" console device,
   which directs the console I/O through Xen to the same console device Xen
   itself uses (in this case, the serial port).
   
   In an attempt to add performance, one can also add
   
         dom0_max_vcpus=1 dom0_vcpus_pin          dom0_max_vcpus=1 dom0_vcpus_pin
   
Line 459  grub was recommended.  If necessary, see Line 388  grub was recommended.  If necessary, see
 [old grub information](/ports/xen/howto-grub).  [old grub information](/ports/xen/howto-grub).
   
 The [HowTo on Installing into  The [HowTo on Installing into
 RAID-1](http://mail-index.NetBSD.org/port-xen/2006/03/01/0010.html)  RAID-1](https://mail-index.NetBSD.org/port-xen/2006/03/01/0010.html)
 explains how to set up booting a dom0 with Xen using grub with  explains how to set up booting a dom0 with Xen using grub with
 NetBSD's RAIDframe.  (This is obsolete with the use of NetBSD's native  NetBSD's RAIDframe.  (This is obsolete with the use of NetBSD's native
 boot.  Now, just create a system with RAID-1, and alter /boot.cfg as  boot.  Now, just create a system with RAID-1, and alter /boot.cfg as
Line 585  section. Line 514  section.
         # Install secondary boot loader          # Install secondary boot loader
         cp -p /usr/mdec/boot /          cp -p /usr/mdec/boot /
         # Create boot.cfg following earlier guidance:          # Create boot.cfg following earlier guidance:
         menu=Xen:load /netbsd-XEN3PAE_DOM0.gz console=pc;multiboot /xen.gz dom0_mem=256M          menu=Xen:load /netbsd-XEN3PAE_DOM0.gz console=pc;multiboot /xen.gz dom0_mem=512M
         menu=Xen.ok:load /netbsd-XEN3PAE_DOM0.ok.gz console=pc;multiboot /xen.ok.gz dom0_mem=256M          menu=Xen.ok:load /netbsd-XEN3PAE_DOM0.ok.gz console=pc;multiboot /xen.ok.gz dom0_mem=512M
         menu=GENERIC:boot          menu=GENERIC:boot
         menu=GENERIC single-user:boot -s          menu=GENERIC single-user:boot -s
         menu=GENERIC.ok:boot netbsd.ok          menu=GENERIC.ok:boot netbsd.ok
Line 659  In 2015-01, the following combination wa Line 588  In 2015-01, the following combination wa
         dom0 kernel: NetBSD/amd64 6.1.5          dom0 kernel: NetBSD/amd64 6.1.5
         Xen tools: xentools42-4.2.5 from pkgsrc          Xen tools: xentools42-4.2.5 from pkgsrc
   
 See [PR 47720](http://gnats.netbsd.org/47720) for a problem with dom0  See [PR 47720](https://gnats.netbsd.org/47720) for a problem with dom0
 shutdown.  shutdown.
   
 Unprivileged domains (domU)  Unprivileged domains (domU)
Line 855  Sizing domains Line 784  Sizing domains
   
 Modern x86 hardware has vast amounts of resources.  However, many  Modern x86 hardware has vast amounts of resources.  However, many
 virtual servers can function just fine on far less.  A system with  virtual servers can function just fine on far less.  A system with
 256M of RAM and a 4G disk can be a reasonable choice.  Note that it is  512M of RAM and a 4G disk can be a reasonable choice.  Note that it is
 far easier to adjust virtual resources than physical ones.  For  far easier to adjust virtual resources than physical ones.  For
 memory, it's just a config file edit and a reboot.  For disk, one can  memory, it's just a config file edit and a reboot.  For disk, one can
 create a new file and vnconfig it (or lvm), and then dump/restore,  create a new file and vnconfig it (or lvm), and then dump/restore,
Line 1143  to update the special boot partition. Line 1072  to update the special boot partition.
 Amazon  Amazon
 ------  ------
   
 See the [Amazon EC2 page](../amazon_ec2/).  See the [Amazon EC2 page](/amazon_ec2/).
   
 Using npf  
 ---------  
   
 In standard kernels, npf is a module, and thus cannot be loaded in a  
 DOMU kernel.  
   
 TODO: Explain how to compile npf into a custom kernel, answering (but  
 note that the problem was caused by not booting the right kernel)  
 [this email to  
 netbsd-users](http://mail-index.netbsd.org/netbsd-users/2014/12/26/msg015576.html).  
   
 TODO items for improving NetBSD/xen  TODO items for improving NetBSD/xen
 ===================================  ===================================
Line 1169  TODO items for improving NetBSD/xen Line 1087  TODO items for improving NetBSD/xen
     fragsize/blocksize (UFS2 support may be present; the point is to      fragsize/blocksize (UFS2 support may be present; the point is to
     make it so that with any UFS1/UFS2 file system setup that works      make it so that with any UFS1/UFS2 file system setup that works
     with NetBSD grub will also work).      with NetBSD grub will also work).
     See [pkg/40258](http://gnats.netbsd.org/40258).      See [pkg/40258](https://gnats.netbsd.org/40258).
   * Push patches upstream.    * Push patches upstream.
   * Get UFS2 patches into pvgrub.    * Get UFS2 patches into pvgrub.
 * Add support for PV ops to a version of /boot, and make it usable as  * Add support for PV ops to a version of /boot, and make it usable as
   a kernel in Xen, similar to pvgrub.    a kernel in Xen, similar to pvgrub.
 * Solve somehow the issue with modules for GENERIC not being loadable  
   in a Xen dom0 or domU kernel.  
   
 Random pointers  Random pointers
 ===============  ===============

Removed from v.1.135  
changed lines
  Added in v.1.147


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