| <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" |
| "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" |
| [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] > |
| <!--SPDX-License-Identifier: CC-BY-2.0-UK--> |
| |
| <chapter id='dev-manual-qemu'> |
| |
| <title>Using the Quick EMUlator (QEMU)</title> |
| |
| <para> |
| The Yocto Project uses an implementation of the Quick EMUlator (QEMU) |
| Open Source project as part of the Yocto Project development "tool |
| set". |
| This chapter provides both procedures that show you how to use the |
| Quick EMUlator (QEMU) and other QEMU information helpful for |
| development purposes. |
| </para> |
| |
| <section id='qemu-dev-overview'> |
| <title>Overview</title> |
| |
| <para> |
| Within the context of the Yocto Project, QEMU is an |
| emulator and virtualization machine that allows you to run a |
| complete image you have built using the Yocto Project as just |
| another task on your build system. |
| QEMU is useful for running and testing images and applications on |
| supported Yocto Project architectures without having actual |
| hardware. |
| Among other things, the Yocto Project uses QEMU to run automated |
| Quality Assurance (QA) tests on final images shipped with each |
| release. |
| <note> |
| This implementation is not the same as QEMU in general. |
| </note> |
| This section provides a brief reference for the Yocto Project |
| implementation of QEMU. |
| </para> |
| |
| <para> |
| For official information and documentation on QEMU in general, see |
| the following references: |
| <itemizedlist> |
| <listitem><para> |
| <emphasis><ulink url='http://wiki.qemu.org/Main_Page'>QEMU Website</ulink>:</emphasis> |
| The official website for the QEMU Open Source project. |
| </para></listitem> |
| <listitem><para> |
| <emphasis><ulink url='http://wiki.qemu.org/Manual'>Documentation</ulink>:</emphasis> |
| The QEMU user manual. |
| </para></listitem> |
| </itemizedlist> |
| </para> |
| </section> |
| |
| <section id='qemu-running-qemu'> |
| <title>Running QEMU</title> |
| |
| <para> |
| To use QEMU, you need to have QEMU installed and initialized as |
| well as have the proper artifacts (i.e. image files and root |
| filesystems) available. |
| Follow these general steps to run QEMU: |
| <orderedlist> |
| <listitem><para> |
| <emphasis>Install QEMU:</emphasis> |
| QEMU is made available with the Yocto Project a number of |
| ways. |
| One method is to install a Software Development Kit (SDK). |
| See |
| "<ulink url='&YOCTO_DOCS_SDK_URL;#the-qemu-emulator'>The QEMU Emulator</ulink>" |
| section in the Yocto Project Application Development and |
| the Extensible Software Development Kit (eSDK) manual |
| for information on how to install QEMU. |
| </para></listitem> |
| <listitem><para> |
| <emphasis>Setting Up the Environment:</emphasis> |
| How you set up the QEMU environment depends on how you |
| installed QEMU: |
| <itemizedlist> |
| <listitem><para> |
| If you cloned the <filename>poky</filename> |
| repository or you downloaded and unpacked a |
| Yocto Project release tarball, you can source |
| the build environment script (i.e. |
| <ulink url='&YOCTO_DOCS_REF_URL;#structure-core-script'><filename>&OE_INIT_FILE;</filename></ulink>): |
| <literallayout class='monospaced'> |
| $ cd ~/poky |
| $ source oe-init-build-env |
| </literallayout> |
| </para></listitem> |
| <listitem><para> |
| If you installed a cross-toolchain, you can |
| run the script that initializes the toolchain. |
| For example, the following commands run the |
| initialization script from the default |
| <filename>poky_sdk</filename> directory: |
| <literallayout class='monospaced'> |
| . ~/poky_sdk/environment-setup-core2-64-poky-linux |
| </literallayout> |
| </para></listitem> |
| </itemizedlist> |
| </para></listitem> |
| <listitem><para> |
| <emphasis>Ensure the Artifacts are in Place:</emphasis> |
| You need to be sure you have a pre-built kernel that |
| will boot in QEMU. |
| You also need the target root filesystem for your target |
| machine's architecture: |
| <itemizedlist> |
| <listitem><para> |
| If you have previously built an image for QEMU |
| (e.g. <filename>qemux86</filename>, |
| <filename>qemuarm</filename>, and so forth), |
| then the artifacts are in place in your |
| <ulink url='&YOCTO_DOCS_REF_URL;#build-directory'>Build Directory</ulink>. |
| </para></listitem> |
| <listitem><para> |
| If you have not built an image, you can go to the |
| <ulink url='&YOCTO_MACHINES_DL_URL;'>machines/qemu</ulink> |
| area and download a pre-built image that matches |
| your architecture and can be run on QEMU. |
| </para></listitem> |
| </itemizedlist></para> |
| |
| <para>See the |
| "<ulink url='&YOCTO_DOCS_SDK_URL;#sdk-extracting-the-root-filesystem'>Extracting the Root Filesystem</ulink>" |
| section in the Yocto Project Application Development and |
| the Extensible Software Development Kit (eSDK) manual |
| for information on how to extract a root filesystem. |
| </para></listitem> |
| <listitem><para> |
| <emphasis>Run QEMU:</emphasis> |
| The basic <filename>runqemu</filename> command syntax is as |
| follows: |
| <literallayout class='monospaced'> |
| $ runqemu [<replaceable>option</replaceable> ] [...] |
| </literallayout> |
| Based on what you provide on the command line, |
| <filename>runqemu</filename> does a good job of figuring |
| out what you are trying to do. |
| For example, by default, QEMU looks for the most recently |
| built image according to the timestamp when it needs to |
| look for an image. |
| Minimally, through the use of options, you must provide |
| either a machine name, a virtual machine image |
| (<filename>*wic.vmdk</filename>), or a kernel image |
| (<filename>*.bin</filename>).</para> |
| |
| <para>Here are some additional examples to help illustrate |
| further QEMU: |
| <itemizedlist> |
| <listitem><para> |
| This example starts QEMU with |
| <replaceable>MACHINE</replaceable> set to "qemux86-64". |
| Assuming a standard |
| <ulink url='&YOCTO_DOCS_REF_URL;#build-directory'>Build Directory</ulink>, |
| <filename>runqemu</filename> automatically finds the |
| <filename>bzImage-qemux86-64.bin</filename> image file and |
| the |
| <filename>core-image-minimal-qemux86-64-20200218002850.rootfs.ext4</filename> |
| (assuming the current build created a |
| <filename>core-image-minimal</filename> image). |
| <note> |
| When more than one image with the same name exists, QEMU finds |
| and uses the most recently built image according to the |
| timestamp. |
| </note> |
| <literallayout class='monospaced'> |
| $ runqemu qemux86-64 |
| </literallayout> |
| </para></listitem> |
| <listitem><para> |
| This example produces the exact same results as the |
| previous example. |
| This command, however, specifically provides the image |
| and root filesystem type. |
| <literallayout class='monospaced'> |
| $ runqemu qemux86-64 core-image-minimal ext4 |
| </literallayout> |
| </para></listitem> |
| <listitem><para> |
| This example specifies to boot an initial RAM disk image |
| and to enable audio in QEMU. |
| For this case, <filename>runqemu</filename> set the |
| internal variable <filename>FSTYPE</filename> to |
| "cpio.gz". |
| Also, for audio to be enabled, an appropriate driver must |
| be installed (see the previous description for the |
| <filename>audio</filename> option for more information). |
| <literallayout class='monospaced'> |
| $ runqemu qemux86-64 ramfs audio |
| </literallayout> |
| </para></listitem> |
| <listitem><para> |
| This example does not provide enough information for |
| QEMU to launch. |
| While the command does provide a root filesystem type, it |
| must also minimally provide a |
| <replaceable>MACHINE</replaceable>, |
| <replaceable>KERNEL</replaceable>, or |
| <replaceable>VM</replaceable> option. |
| <literallayout class='monospaced'> |
| $ runqemu ext4 |
| </literallayout> |
| </para></listitem> |
| <listitem><para> |
| This example specifies to boot a virtual machine |
| image (<filename>.wic.vmdk</filename> file). |
| From the <filename>.wic.vmdk</filename>, |
| <filename>runqemu</filename> determines the QEMU |
| architecture (<replaceable>MACHINE</replaceable>) to be |
| "qemux86-64" and the root filesystem type to be "vmdk". |
| <literallayout class='monospaced'> |
| $ runqemu /home/scott-lenovo/vm/core-image-minimal-qemux86-64.wic.vmdk |
| </literallayout> |
| </para></listitem> |
| </itemizedlist> |
| </para></listitem> |
| </orderedlist> |
| </para> |
| </section> |
| |
| <section id='switching-between-consoles'> |
| <title>Switching Between Consoles</title> |
| |
| <para> |
| When booting or running QEMU, you can switch between |
| supported consoles by using |
| Ctrl+Alt+<replaceable>number</replaceable>. |
| For example, Ctrl+Alt+3 switches you to the serial console |
| as long as that console is enabled. |
| Being able to switch consoles is helpful, for example, if |
| the main QEMU console breaks for some reason. |
| <note> |
| Usually, "2" gets you to the main console and "3" |
| gets you to the serial console. |
| </note> |
| </para> |
| </section> |
| |
| <section id='removing-the-splash-screen'> |
| <title>Removing the Splash Screen</title> |
| |
| <para> |
| You can remove the splash screen when QEMU is booting by |
| using Alt+left. |
| Removing the splash screen allows you to see what is |
| happening in the background. |
| </para> |
| </section> |
| |
| <section id='disabling-the-cursor-grab'> |
| <title>Disabling the Cursor Grab</title> |
| |
| <para> |
| The default QEMU integration captures the cursor within the |
| main window. |
| It does this since standard mouse devices only provide |
| relative input and not absolute coordinates. |
| You then have to break out of the grab using the "Ctrl+Alt" |
| key combination. |
| However, the Yocto Project's integration of QEMU enables |
| the wacom USB touch pad driver by default to allow input |
| of absolute coordinates. |
| This default means that the mouse can enter and leave the |
| main window without the grab taking effect leading to a |
| better user experience. |
| </para> |
| </section> |
| |
| <section id='qemu-running-under-a-network-file-system-nfs-server'> |
| <title>Running Under a Network File System (NFS) Server</title> |
| |
| <para> |
| One method for running QEMU is to run it on an NFS server. |
| This is useful when you need to access the same file system |
| from both the build and the emulated system at the same time. |
| It is also worth noting that the system does not need root |
| privileges to run. |
| It uses a user space NFS server to avoid that. |
| Follow these steps to set up for running QEMU using an NFS |
| server. |
| <orderedlist> |
| <listitem><para> |
| <emphasis>Extract a Root Filesystem:</emphasis> |
| Once you are able to run QEMU in your environment, you can |
| use the <filename>runqemu-extract-sdk</filename> script, |
| which is located in the <filename>scripts</filename> |
| directory along with the <filename>runqemu</filename> |
| script.</para> |
| |
| <para>The <filename>runqemu-extract-sdk</filename> takes a |
| root filesystem tarball and extracts it into a location |
| that you specify. |
| Here is an example that takes a file system and |
| extracts it to a directory named |
| <filename>test-nfs</filename>: |
| <literallayout class='monospaced'> |
| runqemu-extract-sdk ./tmp/deploy/images/qemux86-64/core-image-sato-qemux86-64.tar.bz2 test-nfs |
| </literallayout> |
| </para></listitem> |
| <listitem><para> |
| <emphasis>Start QEMU:</emphasis> |
| Once you have extracted the file system, you can run |
| <filename>runqemu</filename> normally with the additional |
| location of the file system. |
| You can then also make changes to the files within |
| <filename>./test-nfs</filename> and see those changes |
| appear in the image in real time. |
| Here is an example using the <filename>qemux86</filename> |
| image: |
| <literallayout class='monospaced'> |
| runqemu qemux86-64 ./test-nfs |
| </literallayout> |
| </para></listitem> |
| </orderedlist> |
| <note> |
| <para> |
| Should you need to start, stop, or restart the NFS share, |
| you can use the following commands: |
| <itemizedlist> |
| <listitem><para> |
| The following command starts the NFS share: |
| <literallayout class='monospaced'> |
| runqemu-export-rootfs start <replaceable>file-system-location</replaceable> |
| </literallayout> |
| </para></listitem> |
| <listitem><para> |
| The following command stops the NFS share: |
| <literallayout class='monospaced'> |
| runqemu-export-rootfs stop <replaceable>file-system-location</replaceable> |
| </literallayout> |
| </para></listitem> |
| <listitem><para> |
| The following command restarts the NFS share: |
| <literallayout class='monospaced'> |
| runqemu-export-rootfs restart <replaceable>file-system-location</replaceable> |
| </literallayout> |
| </para></listitem> |
| </itemizedlist> |
| </para> |
| </note> |
| </para> |
| </section> |
| |
| <section id='qemu-kvm-cpu-compatibility'> |
| <title>QEMU CPU Compatibility Under KVM</title> |
| |
| <para> |
| By default, the QEMU build compiles for and targets 64-bit and x86 |
| <trademark class='registered'>Intel</trademark> <trademark class='trademark'>Core</trademark>2 |
| Duo processors and 32-bit x86 |
| <trademark class='registered'>Intel</trademark> <trademark class='registered'>Pentium</trademark> |
| II processors. |
| QEMU builds for and targets these CPU types because they display |
| a broad range of CPU feature compatibility with many commonly |
| used CPUs. |
| </para> |
| |
| <para> |
| Despite this broad range of compatibility, the CPUs could support |
| a feature that your host CPU does not support. |
| Although this situation is not a problem when QEMU uses software |
| emulation of the feature, it can be a problem when QEMU is |
| running with KVM enabled. |
| Specifically, software compiled with a certain CPU feature crashes |
| when run on a CPU under KVM that does not support that feature. |
| To work around this problem, you can override QEMU's runtime CPU |
| setting by changing the <filename>QB_CPU_KVM</filename> |
| variable in <filename>qemuboot.conf</filename> in the |
| <ulink url='&YOCTO_DOCS_REF_URL;#build-directory'>Build Directory's</ulink> |
| <filename>deploy/image</filename> directory. |
| This setting specifies a <filename>-cpu</filename> option |
| passed into QEMU in the <filename>runqemu</filename> script. |
| Running <filename>qemu -cpu help</filename> returns a list of |
| available supported CPU types. |
| </para> |
| </section> |
| |
| <section id='qemu-dev-performance'> |
| <title>QEMU Performance</title> |
| |
| <para> |
| Using QEMU to emulate your hardware can result in speed issues |
| depending on the target and host architecture mix. |
| For example, using the <filename>qemux86</filename> image in the |
| emulator on an Intel-based 32-bit (x86) host machine is fast |
| because the target and host architectures match. |
| On the other hand, using the <filename>qemuarm</filename> image |
| on the same Intel-based host can be slower. |
| But, you still achieve faithful emulation of ARM-specific issues. |
| </para> |
| |
| <para> |
| To speed things up, the QEMU images support using |
| <filename>distcc</filename> to call a cross-compiler outside the |
| emulated system. |
| If you used <filename>runqemu</filename> to start QEMU, and the |
| <filename>distccd</filename> application is present on the host |
| system, any BitBake cross-compiling toolchain available from the |
| build system is automatically used from within QEMU simply by |
| calling <filename>distcc</filename>. |
| You can accomplish this by defining the cross-compiler variable |
| (e.g. <filename>export CC="distcc"</filename>). |
| Alternatively, if you are using a suitable SDK image or the |
| appropriate stand-alone toolchain is present, the toolchain is |
| also automatically used. |
| <note> |
| Several mechanisms exist that let you connect to the system |
| running on the QEMU emulator: |
| <itemizedlist> |
| <listitem><para> |
| QEMU provides a framebuffer interface that makes |
| standard consoles available. |
| </para></listitem> |
| <listitem><para> |
| Generally, headless embedded devices have a serial port. |
| If so, you can configure the operating system of the |
| running image to use that port to run a console. |
| The connection uses standard IP networking. |
| </para></listitem> |
| <listitem><para> |
| SSH servers exist in some QEMU images. |
| The <filename>core-image-sato</filename> QEMU image |
| has a Dropbear secure shell (SSH) server that runs |
| with the root password disabled. |
| The <filename>core-image-full-cmdline</filename> and |
| <filename>core-image-lsb</filename> QEMU images |
| have OpenSSH instead of Dropbear. |
| Including these SSH servers allow you to use standard |
| <filename>ssh</filename> and <filename>scp</filename> |
| commands. |
| The <filename>core-image-minimal</filename> QEMU image, |
| however, contains no SSH server. |
| </para></listitem> |
| <listitem><para> |
| You can use a provided, user-space NFS server to boot |
| the QEMU session using a local copy of the root |
| filesystem on the host. |
| In order to make this connection, you must extract a |
| root filesystem tarball by using the |
| <filename>runqemu-extract-sdk</filename> command. |
| After running the command, you must then point the |
| <filename>runqemu</filename> |
| script to the extracted directory instead of a root |
| filesystem image file. |
| See the |
| "<link linkend='qemu-running-under-a-network-file-system-nfs-server'>Running Under a Network File System (NFS) Server</link>" |
| section for more information. |
| </para></listitem> |
| </itemizedlist> |
| </note> |
| </para> |
| </section> |
| |
| <section id='qemu-dev-command-line-syntax'> |
| <title>QEMU Command-Line Syntax</title> |
| |
| <para> |
| The basic <filename>runqemu</filename> command syntax is as |
| follows: |
| <literallayout class='monospaced'> |
| $ runqemu [<replaceable>option</replaceable> ] [...] |
| </literallayout> |
| Based on what you provide on the command line, |
| <filename>runqemu</filename> does a good job of figuring out what |
| you are trying to do. |
| For example, by default, QEMU looks for the most recently built |
| image according to the timestamp when it needs to look for an |
| image. |
| Minimally, through the use of options, you must provide either |
| a machine name, a virtual machine image |
| (<filename>*wic.vmdk</filename>), or a kernel image |
| (<filename>*.bin</filename>). |
| </para> |
| |
| <para> |
| Following is the command-line help output for the |
| <filename>runqemu</filename> command: |
| <literallayout class='monospaced'> |
| $ runqemu --help |
| |
| Usage: you can run this script with any valid combination |
| of the following environment variables (in any order): |
| KERNEL - the kernel image file to use |
| ROOTFS - the rootfs image file or nfsroot directory to use |
| MACHINE - the machine name (optional, autodetected from KERNEL filename if unspecified) |
| Simplified QEMU command-line options can be passed with: |
| nographic - disable video console |
| serial - enable a serial console on /dev/ttyS0 |
| slirp - enable user networking, no root privileges is required |
| kvm - enable KVM when running x86/x86_64 (VT-capable CPU required) |
| kvm-vhost - enable KVM with vhost when running x86/x86_64 (VT-capable CPU required) |
| publicvnc - enable a VNC server open to all hosts |
| audio - enable audio |
| [*/]ovmf* - OVMF firmware file or base name for booting with UEFI |
| tcpserial=<port> - specify tcp serial port number |
| biosdir=<dir> - specify custom bios dir |
| biosfilename=<filename> - specify bios filename |
| qemuparams=<xyz> - specify custom parameters to QEMU |
| bootparams=<xyz> - specify custom kernel parameters during boot |
| help, -h, --help: print this text |
| |
| Examples: |
| runqemu |
| runqemu qemuarm |
| runqemu tmp/deploy/images/qemuarm |
| runqemu tmp/deploy/images/qemux86/<qemuboot.conf> |
| runqemu qemux86-64 core-image-sato ext4 |
| runqemu qemux86-64 wic-image-minimal wic |
| runqemu path/to/bzImage-qemux86.bin path/to/nfsrootdir/ serial |
| runqemu qemux86 iso/hddimg/wic.vmdk/wic.qcow2/wic.vdi/ramfs/cpio.gz... |
| runqemu qemux86 qemuparams="-m 256" |
| runqemu qemux86 bootparams="psplash=false" |
| runqemu path/to/<image>-<machine>.wic |
| runqemu path/to/<image>-<machine>.wic.vmdk |
| </literallayout> |
| </para> |
| </section> |
| |
| <section id='qemu-dev-runqemu-command-line-options'> |
| <title><filename>runqemu</filename> Command-Line Options</title> |
| |
| <para> |
| Following is a description of <filename>runqemu</filename> |
| options you can provide on the command line: |
| <note><title>Tip</title> |
| If you do provide some "illegal" option combination or perhaps |
| you do not provide enough in the way of options, |
| <filename>runqemu</filename> provides appropriate error |
| messaging to help you correct the problem. |
| </note> |
| <itemizedlist> |
| <listitem><para> |
| <replaceable>QEMUARCH</replaceable>: |
| The QEMU machine architecture, which must be "qemuarm", |
| "qemuarm64", "qemumips", "qemumips64", "qemuppc", |
| "qemux86", or "qemux86-64". |
| </para></listitem> |
| <listitem><para> |
| <filename><replaceable>VM</replaceable></filename>: |
| The virtual machine image, which must be a |
| <filename>.wic.vmdk</filename> file. |
| Use this option when you want to boot a |
| <filename>.wic.vmdk</filename> image. |
| The image filename you provide must contain one of the |
| following strings: "qemux86-64", "qemux86", "qemuarm", |
| "qemumips64", "qemumips", "qemuppc", or "qemush4". |
| </para></listitem> |
| <listitem><para> |
| <replaceable>ROOTFS</replaceable>: |
| A root filesystem that has one of the following |
| filetype extensions: "ext2", "ext3", "ext4", "jffs2", |
| "nfs", or "btrfs". |
| If the filename you provide for this option uses "nfs", it |
| must provide an explicit root filesystem path. |
| </para></listitem> |
| <listitem><para> |
| <replaceable>KERNEL</replaceable>: |
| A kernel image, which is a <filename>.bin</filename> file. |
| When you provide a <filename>.bin</filename> file, |
| <filename>runqemu</filename> detects it and assumes the |
| file is a kernel image. |
| </para></listitem> |
| <listitem><para> |
| <replaceable>MACHINE</replaceable>: |
| The architecture of the QEMU machine, which must be one |
| of the following: "qemux86", "qemux86-64", "qemuarm", |
| "qemuarm64", "qemumips", "qemumips64", or "qemuppc". |
| The <replaceable>MACHINE</replaceable> and |
| <replaceable>QEMUARCH</replaceable> options are basically |
| identical. |
| If you do not provide a <replaceable>MACHINE</replaceable> |
| option, <filename>runqemu</filename> tries to determine |
| it based on other options. |
| </para></listitem> |
| <listitem><para> |
| <filename>ramfs</filename>: |
| Indicates you are booting an initial RAM disk (initramfs) |
| image, which means the <filename>FSTYPE</filename> is |
| <filename>cpio.gz</filename>. |
| </para></listitem> |
| <listitem><para> |
| <filename>iso</filename>: |
| Indicates you are booting an ISO image, which means the |
| <filename>FSTYPE</filename> is |
| <filename>.iso</filename>. |
| </para></listitem> |
| <listitem><para> |
| <filename>nographic</filename>: |
| Disables the video console, which sets the console to |
| "ttys0". |
| This option is useful when you have logged into a server |
| and you do not want to disable forwarding from the |
| X Window System (X11) to your workstation or laptop. |
| </para></listitem> |
| <listitem><para> |
| <filename>serial</filename>: |
| Enables a serial console on |
| <filename>/dev/ttyS0</filename>. |
| </para></listitem> |
| <listitem><para> |
| <filename>biosdir</filename>: |
| Establishes a custom directory for BIOS, VGA BIOS and |
| keymaps. |
| </para></listitem> |
| <listitem><para> |
| <filename>biosfilename</filename>: |
| Establishes a custom BIOS name. |
| </para></listitem> |
| <listitem><para> |
| <filename>qemuparams=\"<replaceable>xyz</replaceable>\"</filename>: |
| Specifies custom QEMU parameters. |
| Use this option to pass options other than the simple |
| "kvm" and "serial" options. |
| </para></listitem> |
| <listitem><para><filename>bootparams=\"<replaceable>xyz</replaceable>\"</filename>: |
| Specifies custom boot parameters for the kernel. |
| </para></listitem> |
| <listitem><para> |
| <filename>audio</filename>: |
| Enables audio in QEMU. |
| The <replaceable>MACHINE</replaceable> option must be |
| either "qemux86" or "qemux86-64" in order for audio to be |
| enabled. |
| Additionally, the <filename>snd_intel8x0</filename> |
| or <filename>snd_ens1370</filename> driver must be |
| installed in linux guest. |
| </para></listitem> |
| <listitem><para> |
| <filename>slirp</filename>: |
| Enables "slirp" networking, which is a different way |
| of networking that does not need root access |
| but also is not as easy to use or comprehensive |
| as the default. |
| </para></listitem> |
| <listitem><para id='kvm-cond'> |
| <filename>kvm</filename>: |
| Enables KVM when running "qemux86" or "qemux86-64" |
| QEMU architectures. |
| For KVM to work, all the following conditions must be met: |
| <itemizedlist> |
| <listitem><para> |
| Your <replaceable>MACHINE</replaceable> must be either |
| qemux86" or "qemux86-64". |
| </para></listitem> |
| <listitem><para> |
| Your build host has to have the KVM modules |
| installed, which are |
| <filename>/dev/kvm</filename>. |
| </para></listitem> |
| <listitem><para> |
| The build host <filename>/dev/kvm</filename> |
| directory has to be both writable and readable. |
| </para></listitem> |
| </itemizedlist> |
| </para></listitem> |
| <listitem><para> |
| <filename>kvm-vhost</filename>: |
| Enables KVM with VHOST support when running "qemux86" |
| or "qemux86-64" QEMU architectures. |
| For KVM with VHOST to work, the following conditions must |
| be met: |
| <itemizedlist> |
| <listitem><para> |
| <link linkend='kvm-cond'>kvm</link> option |
| conditions must be met. |
| </para></listitem> |
| <listitem><para> |
| Your build host has to have virtio net device, which |
| are <filename>/dev/vhost-net</filename>. |
| </para></listitem> |
| <listitem><para> |
| The build host <filename>/dev/vhost-net</filename> |
| directory has to be either readable or writable |
| and "slirp-enabled". |
| </para></listitem> |
| </itemizedlist> |
| </para></listitem> |
| <listitem><para> |
| <filename>publicvnc</filename>: |
| Enables a VNC server open to all hosts. |
| </para></listitem> |
| </itemizedlist> |
| </para> |
| </section> |
| </chapter> |
| <!-- |
| vim: expandtab tw=80 ts=4 |
| --> |