\setlength\parindent{0in}
\setlength\parskip{0.1in}
+\newcommand{\note}[1]{{$\rightarrow$ \bf Note: \emph{#1}}}
+
\begin{document}
\title{
\maketitle
-This manual is written for Internal Palacios developers. It contains
-information on how to obtain the palacios code base, how to go about
+This manual is written for internal Palacios developers. It contains
+information on how to obtain the Palacios code base, how to go about
the development process, and how to commit those changes to the
mainline source tree. This assumes that the reader has read {\em An
Introduction to the Palacios Virtual Machine Monitor -- Release 1.0}
models. A central repository exists that holds the master version of
the code base. This central repository is cloned by multiple people
and in multiple places to support various development efforts. A
-feature of git is that every developer actually has a fully copy of
+feature of \texttt{git} is that every developer actually has a fully copy of
the entire repository, and so can function independently until such
-time as they need to resync with the master version.
+time as they need to re-sync with the master version.
There are typically multiple levels of access to the central
repository, that are granted based on the type of developer being
privileges are:
\begin{itemize}
-\item Core Developers: These are the lead developers and are in
+\item Core developers: These are the lead developers and are in
charge of managing the master repository. They have full read/write
access permissions to the central repository.
-\item Internal Developers: Formal members of the development
+\item Internal developers: Formal members of the development
team. These people are capable of pulling directly from the central
repository, but lack the ability to write directly to it.
-\item External Developers: People who are not actual members of the
+\item External developers: People who are not actual members of the
development team. These people can only access the public repository
which is only updated to contain the release versions.
\end{itemize}
\section{Checking out Palacios}
-The central palacios repository is located on {\em
+The central Palacios repository is located on {\em
newskysaw.cs.northwestern.edu} in {\em /home/palacios/palacios}. All
internal developers have read access to the directory. Each developer
must create their own local version of the repository, this is done
\end{verbatim}
{\em Important:}
-Note that palacios is very actively developed so the contents of the
+Note that Palacios is very actively developed so the contents of the
{\em devel} branch are frequently changing. In order to keep up to
date with the latest version, it is necessary to periodically pull the
latest changes from the master repository by running \verb.git pull..
\section{Checking out Kitten}
Kitten is available from Sandia National Labs, and is the main host OS
-we are targetting with Palacios. Loosely speaking core Palacios
+we are targeting with Palacios. Loosely speaking, core Palacios
developers are internal Kitten developers, and internal Palacios
developers are external Kitten developers. Because we have limited
access to the Kitten repository, we are maintaining a local mirror
Kitten uses Mercurial for their source management, so you will have to
make sure the local mercurial version is configured correctly.
-Specifically you should add the following python path to your shell environment.
+Specifically you should add the following Python path to your shell environment.
\begin{verbatim}
export PYTHONPATH=/usr/local/lib64/python2.4/site-packages/
\end{verbatim}
Both the Kitten and Palacios clone commands should be run from the
-same direcotyr. This means that both repositories should be located at
+same directory. This means that both repositories should be located at
the same directory level. The Kitten build process depends on this.
-{\em Important:} Like Palacios, Kitten is very actively developed so
-source tree is frequently changing. In order to keep up to date with
-the latest version, it is necessary to periodically pull the latest
-changes from the mirror repository by running \verb.hg pull. followed
-by \verb.hg update..
+{\em Important:} Like Palacios, Kitten is under active development,
+and its source tree is frequently changing. In order to keep up to
+date with the latest version, it is necessary to periodically pull the
+latest changes from the mirror repository by running \verb.hg.
+pull. followed by \verb.hg update..
\section{Compiling Palacios}
-Palacios is capable of targeting 32 and 64 bit operating systems, and
-includes a build process that supports both these
+Palacios is capable of targeting 32-bit and 64-bit operating systems,
+and includes a build process that supports both these
architectures. Furthermore, Palacios has multiple build locations,
-with multiple makefiles: a top level build directory and a Palacios
-specific build directory. The Palacios build process first generates a
-static library that includes the Palacios VMM. This static library is
-then linked into a host operating system. Palacios internally supports
-GeekOS and can generate a complete OS image via a unified build
-process. To combine Palacios with Kitten, it is necessary to first
-compile Palacios and then to compile Kitten externally link it with
+with multiple Makefiles: a top level build directory and a
+Palacios-specific build directory. The Palacios build process first
+generates a static library that includes the Palacios VMM. This static
+library is then linked into a host operating system. Palacios
+internally supports GeekOS and can generate a complete OS image via a
+unified build process.
+
+To combine Palacios with Kitten, it is necessary to first compile
+Palacios and then to compile Kitten externally link it with
Palacios. The output of the compilation process is a bit more complex
and generates multiple binaries, and the specifics can be found in the
Makefiles.
The top level build directory provides a number of high level make
targets, and is located in {\em palacios/build/}. It supports building
-32 and 64 bit versions of the Palacios library independently as well
+32-bit and 64-bit versions of the Palacios library independently as well
as building an integrated version of GeekOS. The basic targets are:
\begin{itemize}
\item \verb.make palacios-full32. -- Generates a 32 bit version of the Palacios static library
The second build directory is located at {\em palacios/palacios/build}
and handles only the Palacios compilation process. It supports a
-differnt set of targets and arguments:
+different set of targets and arguments:
\begin{itemize}
\item \verb.make ARCH=32. -- iteratively compiles a 32 bit version of Palacios
\item \verb.make ARCH=64. -- iteratively compiles a 64 bit version of
\section{Compiling Kitten}
-Kitten requires a 64 bit version of Palacios, so make sure that
+Kitten requires a 64-bit version of Palacios, so make sure that
Palacios has been correctly compiled before compiling Kitten.
\subsection{Configuration}
There are some specific configuration options that should be disabled
to work with Palacios. Because Palacios is configured by default to
provide a guest with direct access to the VGA console, the {\em VGA
-console} device driver should be disbabled in the Kitten
+console} device driver should be disabled in the Kitten
configuration. Similarly the {\em VM console} driver should be
disabled as well.
The guest OS that is booted as a VM is included as an ISO image in raw
binary format inside Kitten's {\em init\_task}. To change the guest
-ISO, you must change the makefile for the init\_task. This is located
+ISO, you must change the Makefile for the init\_task. This is located
in {\em user/hello\_world/Makefile} and the syntax is well commented.
On {\em newskysaw} a collection of guest ISO images are located in
{\em /opt/vmm-tools/isos/}.
\subsection{Compilation}
-After Kitten has been configured the compilation can be done. The
+After Kitten has been configured it can be compiled. The
general process is to compile a reference build of Kitten, followed by
compiling Palacios support as a kernel module, and then doing a new
full recompilation of Kitten.
make isoimage
\end{verbatim}
+\note{This should probably explain how to change the iso (helloworld,etc)}
+
This generates an ISO boot image containing Kitten, Palacios, and the
guest that will be run as a VM. The ISO image is located at {\em
./arch/x86\_64/boot/image.iso}.
\section{Running Palacios/Kitten}
-Kitten and Palacios are capable of running under Qemu, which makes
+Kitten and Palacios are capable of running under QEMU, which makes
debugging much simpler.
-The basic form of the command to start the Qemu emulator is:
+The basic form of the command to start the Emu emulator is:
\begin{verbatim}
/usr/local/qemu/bin/qemu-system-x86_64 -smp 1 -m 1024 \
-serial file:./serial.out \
< /dev/null
\end{verbatim}
-The command starts up a single processor emulated machine, with 1gig
-of RAM and a cdrom drive loaded with the Kitten ISO image. Furthermore
-all output to the serial port is written directly to a file called
-{\em serial.out}. This command can be copied into a shell script for easy access.
+The command starts up a single processor emulated machine, with 1GB of
+RAM and a CD-ROM drive loaded with the Kitten ISO image. All output
+to the serial port is written directly to a file called {\em
+ serial.out}. This command can be copied into a shell script for easy
+access.
\section{Development Guidelines}
There are standard requirements we have for code entering the mainline.
-First and foremost, Palacios is designed to be OS indenpendent and
-support 32 and 64 bit architectures. This means that developers should
+First and foremost, Palacios is designed to be OS independent and
+support 32-bit and 64-bit architectures. This means that developers should
not include any external OS specific dependencies in any Palacios
-component. Also all changes need to be tested on both 32 and 64 bit
-architectures to make sure that they compile as well as run corrrectly.
+component. Also all changes need to be tested on both 32-bit and 64-bit
+architectures to make sure that they compile as well as run correctly.
\paragraph*{Coding Style}
overlooked principle of design gives the eye a "place to rest,"
increasing the appeal of a composition through subtle means."
\newline\newline
-Translation: Use the spacebar, newlines, and parentheses.
+Translation: Use the space bar, newlines, and parentheses.
Curly-brackets are not optional, even for single line conditionals.
{\em Good}
-
\begin{verbatim}
if (((a) && (b == 5)) ||
(c != 0)) {
\paragraph*{Fail Stop}
-Because booting a basic linux kernel results in over 1 million VM exits
+Because booting a basic Linux kernel results in over 1 million VM exits
catching silent errors is next to impossible. For this reason
ANY time your code has an error it should return -1, and expect the
execution to halt.
header file. You should make an effort to use static functions
whenever possible.
-\item \verb.v3_. prefix
-\newline
-Major interface functions should be named with the prefix \verb.v3_. This
-xallows easy understanding of how to interact with the subsystems. And
-in the case that they need to be externally visible to the host os,
-make them unlikely to collide with other functions.
+\item \verb.v3_. prefix \newline Major interface functions should be
+ named with the prefix \verb.v3_. This allows easy understanding of
+ how to interact with the subsystems. In the case that they need to
+ be externally visible to the host OS, make them unlikely to collide
+ with other functions.
\end{enumerate}
\paragraph*{Debugging Output}
-Debugging output is sent through the host os via functions in the
+Debugging output is sent through the host OS via functions in the
\verb.os_hooks. structure. These functions have various wrappers of the form
-\verb.Print*., with printf style semantics.
+\verb.Print*., with \texttt{printf}-style semantics.
Two functions of note are \verb.PrintDebug. and \verb.PrintError..
applied to the mainline, it will generate a conflicting commit that
will become present when the developer next pulls from the central
repository. This can result in both repositories getting out of
-sync. It is possible to deal with this by manually rebasing the local
+sync. It is possible to deal with this by manually re-basing the local
repository, but it is difficult and error-prone.
This approach also does not map well when patches are being revised. A
For this reason most internal developers should seriously consider
{\em stacked git}. Stacked git is designed to make patch development
easier and less of a headache. The basic mode of operation is for a
-developer to intialize a patch for a new feature and then continuously
+developer to initialize a patch for a new feature and then continuously
apply changes to the patch. Stacked Git allows a developer to layer a
series of patches on top of a local git repository, without causing
the repository to unsync due to local commits. Basically, the
patch. (This is how you can manage revisions that are made by other developers).
\end{itemize}
-You should definately look at the online documentation to better
+You should definitely look at the online documentation to better
understand how stacked git works. It is not required of course, but if
you want your changes to be applied its up to you to generate a patch
that is acceptable to a core developer. Ultimately using Stacked git
\section{Networking}
-\section{Configuring the development host's Qemu network}
-Set up Tap interfaces:
-
-/root/util/tap\_create tapX
-
-Bridging tapX with eth1 will only work (work = send packet and also
-make packet visible on localhost) if the IP address is set correctly
-(correctly = match network it is connected to e.g., network of eth1)
-so bring up the network inside of the VM / QEMU as 10-net, and it
-should route through the eth1 rule and be visible both on the host and
-in the physical network
-
+Both the Kitten and GeekOS substrates on which Palacios can run
+currently include drivers for two simple network cards, the NE2000,
+and the RTL8139. The Kitten substrate is acquiring an ever increasing
+set of drivers for specialized network systems. A lightweight
+networking stack is included so that TCP/IP networking is possible
+from within the host OS kernel and in Palacios.
+
+When debugging Palacios on QEMU, it is very convenient to add an
+RTL8139 card to your QEMU configuration, and then drive it from within
+Palacios. QEMU can be configured to provide local connectivity to the
+QEMU emulated machine, including bridging the emulated machine with a
+physical network. Local connectivity can be done with redirection, or
+with a TAP interface. For global connectivity, a TAP interface must
+be used; it is bridged to a physical interface.
+
+\section{Configuring the development host's QEMU network}
+
+To get local connectivity with redirection, no networking changes on
+the host are needed. However, people usually want to use TAP-based
+networking, which does require changes. For one thing, TAP interfaces
+can be inspected with tools like wireshark, which makes for much
+easier debugging of network code.
+
+In order to get QEMU networking to function, it is necessary to create
+TAP interfaces, and, optionally, to bridge them to real networks. A
+development machine typically will have several TAP interfaces, and
+more can be created. Generally, each developer should have a TAP
+interface of his or her own. In the following, we will use our
+development machine, newskysaw, as an example.
+
+To set up a TAP interface on newskysaw, the following command is used:
+\begin{verbatim}
+/root/util/tap_create tapX
+\end{verbatim}
-\subsection{Configuring Kitten}
+When QEMU runs with a tap interface, it will use /etc/qemu-ifup to
+bring up the interface. On newskysaw, /etc/qemu-ifup looks like this:
-To enable networking in Qemu, networking needs to be enabled in the configuration.
+\begin{verbatim}
+#!/bin/bash
+echo "Executing /etc/qemu-ifup - no external bridging"
+echo "Bringing up $1 for bridged mode..."
+NET=`echo $1 | cut -dp -f2`
+sudo /sbin/ifconfig $1 172.2${NET}.0.1 up
+sleep 2
+\end{verbatim}
-Make sure turn on the network device driver, networking, and input
-kernel command 'console=serial net=rtl8139'
+The interface tap$N$ is brought up with the IP address 172.2$N$.0.1.
+ifconfig will also create a routing rule that sends 172.2$N$.0.1/16
+traffic to tap$N$. The upshot is that if the code running in QEMU
+uses an IP address in this network (for example: 172.2$N$.0.2), you
+will be able to talk to it from newskysaw. For example, from
+newskysaw, if you ping 172.21.0.2, the packet (and ARP) will go out via
+tap1. The source address will appear to be 172.21.0.1. The QEMU
+machine will see these packets on its interface, and the software
+controlling its interface can respond to 172.21.0.1.
+
+This form of networking is local to the machine. You can also bridge
+a TAP interface with a physical interface. The result of this is that
+a packet sent on it will be sent on the physical interface. To do
+this requires more effort (and is not set up by default on newskysaw).
+As an example, consider that on newskysaw, the physical interface eth1
+is connected to a private network switch to which the lab test
+computers (v-test-amd, v-test-amd2, etc.) are connected. To bridge,
+for example, tap10, to this interface, you would do the following
+(with root's help):
+\begin{enumerate}
+\item You need to bring up eth1 (ifconfig eth1 up {\em address}
+netmask {\em mask}). It is important that the address and mask you
+choose are appropriate for the network eth1 is connected to.
+\item You would bring up tap10 without an address: /sbin/ifconfig
+tap10 up
+\item You would bridge tap10 and eth1: /usr/sbin/brctl addif br0
+tap10; /usr/sbin/brctl addif eth1. This assumes that br0 was
+previously created.
+\end{enumerate}
-How to set ip address in kitten:
+Bridging tap$N$ with eth1 will only work (where ``work'' means sending
+a packet on the network and making the packet visible on localhost) if
+the IP address in the code running in QEMU is set correctly. This
+means that it needs to be set to correspond to the network of eth1).
+For the newskysaw configuration, this is a 10-net address.
-Kitten ip address setting is in file drivers/net/ne2k/rtl8139.c, in the code below which is located in function rtl8139\_init.
- struct ip\_addr ipaddr = { htonl(0 | 10 << 24 | 0 << 16 | 2 << 8 | 16 << 0) };
- struct ip\_addr netmask = { htonl(0xffffff00) };
- struct ip\_addr gw = { htonl(0 | 10 << 24 | 0 << 16 | 2 << 8 | 2 << 0) };
+\subsection{Configuring Kitten}
-This sets the ip address as 10.0.2.16, netmask 255.255.255.0 and gateway address 10.0.2.2, change it as you need.
+Kitten needs to be explicitly configured to use networking. Currently
+only a subset of the networking configurations are supported. To
+enable an Ethernet network you should enable the following options:
+\begin{itemize}
+\item Enable TCP Support
+\item Enable UDP Support
+\item Enable socket API
+\item Enable ARP support
+\end{itemize}
+The other options are not supported, and enabling them will probably
+break the kernel compilation.
-\subsection{Running with networking}
+To allow Kitten to communicate with the QEMU network card you also
+need to enable the appropriate device driver: \newline
+\verb.NE2K Device Driver (rtl8139).
-\paragraph*{Tap Interface}
-In which, the command line:
+The driver then needs to be listed as a Kernel Command Line argument
+in the {\em ISOIMAGE configuration}. To do this add
+\verb.net=rtl819. to the end of the argument string.
--net tap, ifname=tap2
+Kitten currently does not support the dynamic assignment or IP
+addresses at runtime. Because of this it is necessary to hardcode the
+IP address into the device driver. For the rtl8139 network driver look
+in the file {\em drivers/net/ne2k/rtl8139.c} for the function
+\verb.rtl8139_init..
-specifies Qemu to use the host's tap0 as its network interface, then Qemu can access the host's physical network.
+There should be a block of code that looks like the following:
+\begin{verbatim}
+ struct ip_addr ipaddr = { htonl(0 | 10 << 24 | 0 << 16 | 2 << 8 | 16 << 0) };
+ struct ip_addr netmask = { htonl(0xffffff00) };
+ struct ip_addr gw = { htonl(0 | 10 << 24 | 0 << 16 | 2 << 8 | 2 << 0) };
+\end{verbatim}
-\paragraph*{Redirection}
+This sets the IP address as 10.0.2.16, netmask 255.255.255.0 and
+gateway address 10.0.2.2. Change these assignments to match your configuration.
-Also you can use the following command instead to redirect host's 9555 port to Qemu's 80 port.
--net user -net nic,model=rtl8139 -redir tcp:9555::80
+\paragraph*{Kitten as the Guest OS}
-In this case, you can access Qemu's 80 port in the host like:
+When running Kitten as a VM, the above applies except that you will
+want to enable the {\em VMNET} device driver instead of the {\em rtl8139}.
-telnet localhost 9555
-Qemu has many options to build up a virtual or real networking. See http://www.h7.dion.ne.jp/~qemu-win/HowToNetwork-en.html for more information.
+\subsection{Running with networking}
+\paragraph*{TAP Interface}
+Running with a TAP interface provides either local or global
+connectivity (depending on how the TAP interface is configured and/or
+bridged). From the perspective of the QEMU command line, both look
+the same, however. You simply add something like this to the command
+line:
+\begin{verbatim}
+-net tap,ifname=tap2 -net nic,model=rtl8139
+\end{verbatim}
+The first \verb.-net. option indicates that you want to use a tap
+interface, specifically \verb.tap2.. The second \verb.-net. option
+specifies that this interface will appear to code in the QEMU machine
+to be a network interface card of the specific model RTL8139. Note
+that this is a model for which we have a driver. If tap2 were
+bridged, we'd get global connectivity. If not, we would just get
+local connectivity.
+\paragraph*{Redirection}
+It is also possible to achieve limited local connectivity even if you
+have no TAP support on your development machine. In redirection, QEMU
+essentially acts as a proxy, translating TCP or other connections and
+low-level packet operations on the network interface in the QEMU
+machine. For example, the following options will redirect the host's
+9555 port to the QEMU machine's 80 port:
+\begin{verbatim}
+-net user -net nic,model=rtl8139 -redir tcp:9555:10.10.10.33:80
+\end{verbatim}
+The first \verb.-net. option indicates that we are using user-level
+networking (proxying). The second \verb.-net. option indicates that
+this user-level network will appear in the QEMU machine as an RTL8139
+network card. The \verb.-redir. option indicates that connections on
+localhost:9555 will be translated into equivalent packet exchanges on
+the RTL8139 card in the QEMU machine. However, we have to tell QEMU
+which IP address and port to use on the QEMU machine's side. This is
+what the 10.10.10.33 address, and port 80 are. In the example, if you
+access port 9555 on localhost, say with:
+\begin{verbatim}
+telnet localhost 9555
+\end{verbatim}
+The packets that appear in the QEMU machine will be bound for
+10.10.10.33, port 80. Within the QEMU machine, your RTL8139 interface
+had better then be up on that address.
+QEMU has many options to build up virtual or real networking. See
+http://www.h7.dion.ne.jp/$\sim$qemu-win/HowToNetwork-en.html for more
+information.
-For more questions, talk to Jack or Lei.
+For more questions, talk to Jack, Lei, or Peter.
\end{document}
