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Add section on bhyve to Virtualization chapter in prep for closing PR189216.

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Editorial review to follow.

Submitted by:	Allan Jude
Sponsored by:	iXsystems
This commit is contained in:
Dru Lavigne 2014-05-05 16:03:30 +00:00
parent 21b9b455a0
commit a4281c4eb9
Notes: svn2git 2020-12-08 03:00:23 +00:00 
svn path=/head/; revision=44762
1 changed files with 315 additions and 2 deletions

317
en_US.ISO8859-1/books/handbook/virtualization/chapter.xml
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@ -20,6 +20,16 @@
<contrib>Contributed by </contrib>
</author>
</authorgroup>
<authorgroup>
<author>
<personname>
<firstname>Allan</firstname>
<surname>Jude</surname>
</personname>
<contrib>bhyve section by </contrib>
</author>
</authorgroup>
</info>
<sect1 xml:id="virtualization-synopsis">
@ -1110,8 +1120,8 @@ EndSection</programlisting>
</sect2>
</sect1>
<sect1 xml:id="virtualization-host">
<title>&os; as a Host</title>
<sect1 xml:id="virtualization-host-virtualbox">
<title>&os; as a Host with <application>VirtualBox</application></title>
<para><application>&virtualbox;</application> is an actively
developed, complete virtualization package, that is available
@ -1273,7 +1283,310 @@ perm pass* 0660</programlisting>
<screen>&prompt.root; <userinput>service devfs restart</userinput></screen>
</sect2>
</sect1>
<sect1 xml:id="virtualization-host-bhyve">
<title>&os; as a Host with
<application>bhyve</application></title>
<para>Starting with &os; 10.0-RELEASE the BSD licensed hypervisor
<application>bhyve</application> is part of the base system.
<application>bhyve</application> supports a number of guests
including &os;, OpenBSD, and many flavors of &linux;.
<application>bhyve</application> currently only supports a
serial console and does not emulate a graphical console.
<application>bhyve</application> is a legacy-free hypervisor,
meaning that instead of translating instructions, and manually
managing memory mappings, it relies on the virtualization
offload features of newer <acronym>CPU</acronym>s.
<application>bhyve</application> also avoids emulating
compatible hardware for the guest, and instead relies on the
paravirtualization drivers, called
<literal>VirtIO</literal>.</para>
<para>Due to the design of <application>bhyve</application>, it is
only possible to use <application>bhyve</application> on
computers with newer processors that support &intel;
<acronym>EPT</acronym> (Extended Page Tables) or &amd;
<acronym>RVI</acronym> (Rapid Virtualization Indexing, also know
as <acronym>NPT</acronym> or Nested Page Tables). Most newer
processors, specifically the &intel;&nbsp;&core; i3/i5/i7 and
&intel;&nbsp;&xeon; E3/E5/E7 support this feature, for a
complete list of &intel; processors that support
<acronym>EPT</acronym> see the <link
xlink:href="http://ark.intel.com/search/advanced?s=t&amp;ExtendedPageTables=true">&intel;
ARK</link>. <acronym>RVI</acronym> is found on the 3rd
generation and later of the &amd.opteron; (Barcelona)
processors. The easiest way to check for support of
<acronym>EPT</acronym> or <acronym>RVI</acronym> on a system is
to look for the <literal>POPCNT</literal> processor feature flag
on the <literal>Features2</literal> line in
<command>dmesg</command> or
<filename>/var/run/dmesg.boot</filename>.</para>
<sect2 xml:id="virtualization-bhyve-prep">
<title>Preparing the Host</title>
<para>The first step to creating a virtual machine in
<application>bhyve</application> is configuring the host
system. Load the <application>bhyve</application> kernel
module called vmm. Create a <filename>tap</filename>
interface for the network device in the virtual machine to
attach to. Optionally create a bridge interface and add the
<filename>tap</filename> interface as well as the physical
interface as members to allow the virtual machine to have
access to the network.</para>
<screen>&prompt.root; <userinput>kldload vmm</userinput>
&prompt.root; <userinput>kldload nmdm</userinput>
&prompt.root; <userinput>ifconfig <replaceable>tap0</replaceable> create</userinput>
&prompt.root; <userinput>sysctl net.link.tap.up_on_open=1</userinput>
net.link.tap.up_on_open: 0 -> 1
&prompt.root; <userinput>ifconfig <replaceable>bridge0</replaceable> create</userinput>
&prompt.root; <userinput>ifconfig <replaceable>bridge0</replaceable> addm <replaceable>igb0</replaceable> addm <replaceable>tap0</replaceable></userinput>
&prompt.root; <userinput>ifconfig <replaceable>bridge0</replaceable> up</userinput></screen>
</sect2>
<sect2 xml:id="virtualization-bhyve-freebsd">
<title>Creating a FreeBSD Guest</title>
<para>Create a file to use as the virtual disk for the guest
machine.</para>
<screen>&prompt.root; <userinput>truncate -s <replaceable>16G</replaceable> <filename>guest.img</filename></userinput></screen>
<para>Download an installation image of &os; to install:</para>
<screen>&prompt.root; <userinput>fetch <replaceable>ftp://ftp.freebsd.org/pub/FreeBSD/ISO-IMAGES-amd64/10.0/FreeBSD-10.0-RELEASE-amd64-bootonly.iso</replaceable></userinput>
FreeBSD-10.0-RELEASE-amd64-bootonly.iso 100% of 209 MB 570 kBps 06m17s</screen>
<para>&os; comes with an example script for running a virtual
machine in <application>bhyve</application>. The script will
start the virtual machine and run it in a loop, so it will
automatically restart if it crashes. The script takes a
number of options to control the configuration of the machine.
<option>-c</option> controls the number of virtual CPUs.
<option>-m</option> limits the amount of memory available to
the guest. <option>-t</option> defines which
<filename>tap</filename> device to use. <option>-d</option>
indicates which disk image to use. <option>-i</option> tells
<application>bhyve</application> to boot from the CD image
instead of the disk, and <option>-I</option> defines which CD
image to use. Finally the last parameter is the name of the
virtual machine, used to track the running machines. Start
the virtual machine in installation mode:</para>
<screen>&prompt.root; <userinput>sh <filename>/usr/share/examples/bhyve/vmrun.sh</filename> -c <replaceable>4</replaceable> -m <replaceable>1024M</replaceable> -t tap0 -d <filename>guest.img</filename> -i -I <filename>FreeBSD-10.0-RELEASE-amd64-bootonly.iso</filename> <replaceable>guestname</replaceable></userinput></screen>
<para>The system will boot and start the installer. After
installing a system in the virtual machine, when the system
asks about dropping in to a shell at the end of the
installation, choose <guibutton>Yes</guibutton>. A small
change needs to be made to make the system start with a serial
console. Edit <filename>/etc/ttys</filename> and replace the
existing <literal>console</literal> line with:</para>
<programlisting>console "/usr/libexec/getty std.9600" xterm on secure</programlisting>
<para>Reboot the virtual machine. Rebooting the virtual machine
causes <application>bhyve</application> to exit. However the
<filename>vmrun.sh</filename> script runs
<command>bhyve</command> in a loop and will automatically
restart it. When this happens, choose the reboot option from
the boot loader menu, and this will escape the loop. Now the
guest can be started from the virtual disk:</para>
<screen>&prompt.root; <userinput>sh <filename>/usr/share/examples/bhyve/vmrun.sh</filename> -c <replaceable>4</replaceable> -m <replaceable>1024M</replaceable> -t tap0 -d <filename>guest.img</filename> <replaceable>guestname</replaceable></userinput></screen>
</sect2>
<sect2 xml:id="virtualization-bhyve-linux">
<title>Creating a &linux; Guest</title>
<note><para><application>bhyve</application> requires
<package>sysutils/grub2-bhyve</package> in order to boot
operating systems other than &os;.</para></note>
<para>Create a file to use as the virtual disk for the guest
machine.</para>
<screen>&prompt.root; <userinput>truncate -s <replaceable>16G</replaceable> <filename>linux.img</filename></userinput></screen>
<para>Starting a virtual machine with
<application>bhyve</application> is a two step process. First
a kernel must be loaded, then the guest can be started.
<package>sysutils/grub2-bhyve</package> is used to load the
&linux; kernel. Create a <filename>device.map</filename> that
<application>grub</application> will use to map the virtual
devices to the files on the host system:</para>
<programlisting>(hd0) ./linux.img
(cd0) ./somelinux.iso</programlisting>
<para>Use <package>sysutils/grub2-bhyve</package> to load the
&linux; kernel from the <acronym>ISO</acronym> image:</para>
<screen>&prompt.root; <userinput>grub-bhyve -m <filename>device.map</filename> -r cd0 -M <replaceable>1024M</replaceable> <replaceable>linuxguest</replaceable></userinput></screen>
<para>This will start grub. If the installation CD contains a
<filename>grub.cfg</filename> then a menu will be displayed.
If not, the <literal>vmlinuz</literal> and
<literal>initrd</literal> files must be located and loaded
manually:</para>
<screen>grub> <userinput>ls</userinput>
(hd0) (cd0) (cd0,msdos1) (host)
grub> <userinput>ls (cd0)/isolinux</userinput>
boot.cat boot.msg grub.conf initrd.img isolinux.bin isolinux.cfg memtest
splash.jpg TRANS.TBL vesamenu.c32 vmlinuz
grub> <userinput>linux (cd0)/isolinux/vmlinuz</userinput>
grub> <userinput>initrd (cd0)/isolinux/initrd.img</userinput>
grub> <userinput>boot</userinput></screen>
<para>Now that the &linux; kernel is loaded, the guest can be
started:</para>
<screen>&prompt.root; <userinput>bhyve -AI -H -P \
-s 0:0,hostbridge \
-s 1:0,lpc \
-s 2:0,virtio-net,tap1 \
-s 3:0,virtio-blk,./linux.img \
-s 4:0,ahci-cd,./somelinux.iso \
-l com1,stdio \
-c <replaceable>4</replaceable> -m <replaceable>1024M</replaceable> <replaceable>linuxguest</replaceable></userinput></screen>
<para>The system will boot and start the installer. After
installing a system in the virtual machine, reboot the virtual
machine. This will cause <application>bhyve</application> to
exit. The instance of the virtual machine needs to be
destroyed before it can be started again:</para>
<screen>&prompt.root; <userinput>bhyvectl --destroy --vm=<replaceable>linuxguest</replaceable></userinput></screen>
<para>Now the guest can be started directly from the virtual
disk. Load the kernel:</para>
<screen>&prompt.root; <userinput>grub-bhyve -m <filename>device.map</filename> -r hd0,msdos1 -M <replaceable>1024M</replaceable> <replaceable>linuxguest</replaceable></userinput>
grub> <userinput>ls</userinput>
(hd0) (hd0,msdos2) (hd0,msdos1) (cd0) (cd0,msdos1) (host)
(lvm/VolGroup-lv_swap) (lvm/VolGroup-lv_root)
grub> <userinput>ls (hd0,msdos1)/</userinput>
lost+found/ grub/ efi/ System.map-2.6.32-431.el6.x86_64 config-2.6.32-431.el6.x
86_64 symvers-2.6.32-431.el6.x86_64.gz vmlinuz-2.6.32-431.el6.x86_64
initramfs-2.6.32-431.el6.x86_64.img
grub> <userinput>linux (hd0,msdos1)/vmlinuz-2.6.32-431.el6.x86_64 root=/dev/mapper/VolGroup-lv_root</userinput>
grub> <userinput>initrd (hd0,msdos1)/initramfs-2.6.32-431.el6.x86_64.img</userinput>
grub> <userinput>boot</userinput></screen>
<para>Boot the virtual machine:</para>
<screen>&prompt.root; <userinput>bhyve -AI -H -P \
-s 0:0,hostbridge \
-s 1:0,lpc \
-s 2:0,virtio-net,tap1 \
-s 3:0,virtio-blk,./linux.img \
-l com1,stdio \
-c <replaceable>4</replaceable> -m <replaceable>1024M</replaceable> <replaceable>linuxguest</replaceable></userinput></screen>
<para>&linux; will now boot in the virtual machine and
eventually present you with the login prompt. Login and use
the virtual machine. When you are finished, reboot the
virtual machine to exit <application>bhyve</application>.
Destroy the virtual machine instance:</para>
<screen>&prompt.root; <userinput>bhyvectl --destroy --vm=<replaceable>linuxguest</replaceable></userinput></screen>
</sect2>
<sect2 xml:id="virtualization-bhyve-nmdm">
<title>Virtual Machines Consoles</title>
<para>It is advantageous to wrap the
<application>bhyve</application> console in a session
management tool such as <package>sysutils/tmux</package> or
<package>sysutils/screen</package> in order to detach and
reattach to the console. It is also possible to have the
console of <application>bhyve</application> be a null modem
device that can be accessed with <command>cu</command>. Load
the <filename>nmdm</filename> kernel module, and replace
<option>-l com1,stdio</option> with
<option>-l com1,/dev/nmdm0A</option>. The
<filename>/dev/nmdm</filename> devices are created
automatically as needed, each is a pair,
<filename>/dev/nmdm1A</filename> and
<filename>/dev/nmdm1B</filename> corresponding to the two ends
of the null modem cable. See &man.nmdm.4; for more
information.</para>
<screen>&prompt.root; <userinput>bhyve -AI -H -P \
-s 0:0,hostbridge \
-s 1:0,lpc \
-s 2:0,virtio-net,tap1 \
-s 3:0,virtio-blk,./linux.img \
-l com1,<replaceable>/dev/nmdm0A</replaceable> \
-c <replaceable>4</replaceable> -m <replaceable>1024M</replaceable> <replaceable>linuxguest</replaceable></userinput>
&prompt.root; <userinput>cu -l /dev/nmdm0B -s 9600</userinput>
Connected
Ubuntu 13.10 handbook ttyS0
handbook login:</screen>
</sect2>
<sect2 xml:id="virtualization-bhyve-managing">
<title>Managing Virtual Machines</title>
<para>A device node is created in <filename
role="directory">/dev/vmm</filename> for each virtual
machine. This allows the administrator to easily see a list
of the running virtual machines:</para>
<screen>&prompt.root; <userinput>ls -al /dev/vmm</userinput>
total 1
dr-xr-xr-x 2 root wheel 512 Mar 17 12:19 ./
dr-xr-xr-x 14 root wheel 512 Mar 17 06:38 ../
crw------- 1 root wheel 0x1a2 Mar 17 12:20 guestname
crw------- 1 root wheel 0x19f Mar 17 12:19 linuxguest
crw------- 1 root wheel 0x1a1 Mar 17 12:19 otherguest</screen>
<para>Virtual machines can be destroyed using
<command>bhyvectl</command>:</para>
<screen>&prompt.root; bhyvectl --destroy --vm=guestname</screen>
</sect2>
<sect2 xml:id="virtualization-bhyve-onboot">
<title>Persistent Configuration</title>
<para>In order to make the system able to start
<application>bhyve</application> guests at boot time, the
following configurations must be made in the specified
files:</para>
<procedure>
<step>
<title><filename>/etc/sysctl.conf</filename></title>
<programlisting>net.link.tap.up_on_open=1</programlisting>
</step>
<step>
<title><filename>/boot/loader.conf</filename></title>
<programlisting>vmm_load="YES"
nmdm_load="YES"
if_bridge_load="YES"
if_tap_load="YES"</programlisting>
</step>
<step>
<title><filename>/etc/rc.conf</filename></title>
<programlisting>cloned_interfaces="bridge0 tap0"
ifconfig_bridge0="addm igb0 addm tap0"</programlisting>
</step>
</procedure>
</sect2>
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