qemu-doc: convert user-mode emulation to a separate Sphinx manual

The final addition to the set of QEMU manuals is the user-mode emulation
manual, which right now is included in qemu-doc.texi.  Extract it and
convert it to rST, so that qemu-doc.texi covers only full system emulation.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200228153619.9906-2-peter.maydell@linaro.org
Message-id: 20200226113034.6741-2-pbonzini@redhat.com
[PMM: Fix makefile conflicts; add user manual to
 index.rst and index.html.in; don't specify empty man_pages
 list; fixed a few comments to say 'user' rather than 'system']
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 326 insertions, 0 deletions

diff --git a/docs/user/conf.py b/docs/user/conf.py
new file mode 100644
index 0000000000..4b09aedd45
--- /dev/null
+++ b/docs/user/conf.py
@@ -0,0 +1,15 @@
+# -*- coding: utf-8 -*-
+#
+# QEMU documentation build configuration file for the 'user' manual.
+#
+# This includes the top level conf file and then makes any necessary tweaks.
+import sys
+import os
+
+qemu_docdir = os.path.abspath("..")
+parent_config = os.path.join(qemu_docdir, "conf.py")
+exec(compile(open(parent_config, "rb").read(), parent_config, 'exec'))
+
+# This slightly misuses the 'description', but is the best way to get
+# the manual title to appear in the sidebar.
+html_theme_options['description'] = u'User Mode Emulation User''s Guide'
diff --git a/docs/user/index.rst b/docs/user/index.rst
new file mode 100644
index 0000000000..e030dadf65
--- /dev/null
+++ b/docs/user/index.rst
@@ -0,0 +1,16 @@
+.. This is the top level page for the 'user' manual.
+
+
+QEMU User Mode Emulation User's Guide
+=====================================
+
+This manual is the overall guide for users using QEMU
+for user-mode emulation.  In this mode, QEMU can launch
+processes compiled for one CPU on another CPU.
+
+Contents:
+
+.. toctree::
+   :maxdepth: 2
+
+   main
diff --git a/docs/user/main.rst b/docs/user/main.rst
new file mode 100644
index 0000000000..ca69f7727d
--- /dev/null
+++ b/docs/user/main.rst
@@ -0,0 +1,295 @@
+QEMU User space emulator
+========================
+
+Supported Operating Systems
+---------------------------
+
+The following OS are supported in user space emulation:
+
+-  Linux (referred as qemu-linux-user)
+
+-  BSD (referred as qemu-bsd-user)
+
+Features
+--------
+
+QEMU user space emulation has the following notable features:
+
+**System call translation:**
+   QEMU includes a generic system call translator. This means that the
+   parameters of the system calls can be converted to fix endianness and
+   32/64-bit mismatches between hosts and targets. IOCTLs can be
+   converted too.
+
+**POSIX signal handling:**
+   QEMU can redirect to the running program all signals coming from the
+   host (such as ``SIGALRM``), as well as synthesize signals from
+   virtual CPU exceptions (for example ``SIGFPE`` when the program
+   executes a division by zero).
+
+   QEMU relies on the host kernel to emulate most signal system calls,
+   for example to emulate the signal mask. On Linux, QEMU supports both
+   normal and real-time signals.
+
+**Threading:**
+   On Linux, QEMU can emulate the ``clone`` syscall and create a real
+   host thread (with a separate virtual CPU) for each emulated thread.
+   Note that not all targets currently emulate atomic operations
+   correctly. x86 and ARM use a global lock in order to preserve their
+   semantics.
+
+QEMU was conceived so that ultimately it can emulate itself. Although it
+is not very useful, it is an important test to show the power of the
+emulator.
+
+Linux User space emulator
+-------------------------
+
+Quick Start
+~~~~~~~~~~~
+
+In order to launch a Linux process, QEMU needs the process executable
+itself and all the target (x86) dynamic libraries used by it.
+
+-  On x86, you can just try to launch any process by using the native
+   libraries::
+
+      qemu-i386 -L / /bin/ls
+
+   ``-L /`` tells that the x86 dynamic linker must be searched with a
+   ``/`` prefix.
+
+-  Since QEMU is also a linux process, you can launch QEMU with QEMU
+   (NOTE: you can only do that if you compiled QEMU from the sources)::
+
+      qemu-i386 -L / qemu-i386 -L / /bin/ls
+
+-  On non x86 CPUs, you need first to download at least an x86 glibc
+   (``qemu-runtime-i386-XXX-.tar.gz`` on the QEMU web page). Ensure that
+   ``LD_LIBRARY_PATH`` is not set::
+
+      unset LD_LIBRARY_PATH
+
+   Then you can launch the precompiled ``ls`` x86 executable::
+
+      qemu-i386 tests/i386/ls
+
+   You can look at ``scripts/qemu-binfmt-conf.sh`` so that QEMU is
+   automatically launched by the Linux kernel when you try to launch x86
+   executables. It requires the ``binfmt_misc`` module in the Linux
+   kernel.
+
+-  The x86 version of QEMU is also included. You can try weird things
+   such as::
+
+      qemu-i386 /usr/local/qemu-i386/bin/qemu-i386 \
+                /usr/local/qemu-i386/bin/ls-i386
+
+Wine launch
+~~~~~~~~~~~
+
+-  Ensure that you have a working QEMU with the x86 glibc distribution
+   (see previous section). In order to verify it, you must be able to
+   do::
+
+      qemu-i386 /usr/local/qemu-i386/bin/ls-i386
+
+-  Download the binary x86 Wine install (``qemu-XXX-i386-wine.tar.gz``
+   on the QEMU web page).
+
+-  Configure Wine on your account. Look at the provided script
+   ``/usr/local/qemu-i386/bin/wine-conf.sh``. Your previous
+   ``${HOME}/.wine`` directory is saved to ``${HOME}/.wine.org``.
+
+-  Then you can try the example ``putty.exe``::
+
+      qemu-i386 /usr/local/qemu-i386/wine/bin/wine \
+                /usr/local/qemu-i386/wine/c/Program\ Files/putty.exe
+
+Command line options
+~~~~~~~~~~~~~~~~~~~~
+
+::
+
+   qemu-i386 [-h] [-d] [-L path] [-s size] [-cpu model] [-g port] [-B offset] [-R size] program [arguments...]
+
+``-h``
+   Print the help
+
+``-L path``
+   Set the x86 elf interpreter prefix (default=/usr/local/qemu-i386)
+
+``-s size``
+   Set the x86 stack size in bytes (default=524288)
+
+``-cpu model``
+   Select CPU model (-cpu help for list and additional feature
+   selection)
+
+``-E var=value``
+   Set environment var to value.
+
+``-U var``
+   Remove var from the environment.
+
+``-B offset``
+   Offset guest address by the specified number of bytes. This is useful
+   when the address region required by guest applications is reserved on
+   the host. This option is currently only supported on some hosts.
+
+``-R size``
+   Pre-allocate a guest virtual address space of the given size (in
+   bytes). \"G\", \"M\", and \"k\" suffixes may be used when specifying
+   the size.
+
+Debug options:
+
+``-d item1,...``
+   Activate logging of the specified items (use '-d help' for a list of
+   log items)
+
+``-p pagesize``
+   Act as if the host page size was 'pagesize' bytes
+
+``-g port``
+   Wait gdb connection to port
+
+``-singlestep``
+   Run the emulation in single step mode.
+
+Environment variables:
+
+QEMU_STRACE
+   Print system calls and arguments similar to the 'strace' program
+   (NOTE: the actual 'strace' program will not work because the user
+   space emulator hasn't implemented ptrace). At the moment this is
+   incomplete. All system calls that don't have a specific argument
+   format are printed with information for six arguments. Many
+   flag-style arguments don't have decoders and will show up as numbers.
+
+Other binaries
+~~~~~~~~~~~~~~
+
+user mode (Alpha)
+``qemu-alpha`` TODO.
+
+user mode (ARM)
+``qemu-armeb`` TODO.
+
+user mode (ARM)
+``qemu-arm`` is also capable of running ARM \"Angel\" semihosted ELF
+binaries (as implemented by the arm-elf and arm-eabi Newlib/GDB
+configurations), and arm-uclinux bFLT format binaries.
+
+user mode (ColdFire)
+user mode (M68K)
+``qemu-m68k`` is capable of running semihosted binaries using the BDM
+(m5xxx-ram-hosted.ld) or m68k-sim (sim.ld) syscall interfaces, and
+coldfire uClinux bFLT format binaries.
+
+The binary format is detected automatically.
+
+user mode (Cris)
+``qemu-cris`` TODO.
+
+user mode (i386)
+``qemu-i386`` TODO. ``qemu-x86_64`` TODO.
+
+user mode (Microblaze)
+``qemu-microblaze`` TODO.
+
+user mode (MIPS)
+``qemu-mips`` executes 32-bit big endian MIPS binaries (MIPS O32 ABI).
+
+``qemu-mipsel`` executes 32-bit little endian MIPS binaries (MIPS O32
+ABI).
+
+``qemu-mips64`` executes 64-bit big endian MIPS binaries (MIPS N64 ABI).
+
+``qemu-mips64el`` executes 64-bit little endian MIPS binaries (MIPS N64
+ABI).
+
+``qemu-mipsn32`` executes 32-bit big endian MIPS binaries (MIPS N32
+ABI).
+
+``qemu-mipsn32el`` executes 32-bit little endian MIPS binaries (MIPS N32
+ABI).
+
+user mode (NiosII)
+``qemu-nios2`` TODO.
+
+user mode (PowerPC)
+``qemu-ppc64abi32`` TODO. ``qemu-ppc64`` TODO. ``qemu-ppc`` TODO.
+
+user mode (SH4)
+``qemu-sh4eb`` TODO. ``qemu-sh4`` TODO.
+
+user mode (SPARC)
+``qemu-sparc`` can execute Sparc32 binaries (Sparc32 CPU, 32 bit ABI).
+
+``qemu-sparc32plus`` can execute Sparc32 and SPARC32PLUS binaries
+(Sparc64 CPU, 32 bit ABI).
+
+``qemu-sparc64`` can execute some Sparc64 (Sparc64 CPU, 64 bit ABI) and
+SPARC32PLUS binaries (Sparc64 CPU, 32 bit ABI).
+
+BSD User space emulator
+-----------------------
+
+BSD Status
+~~~~~~~~~~
+
+-  target Sparc64 on Sparc64: Some trivial programs work.
+
+Quick Start
+~~~~~~~~~~~
+
+In order to launch a BSD process, QEMU needs the process executable
+itself and all the target dynamic libraries used by it.
+
+-  On Sparc64, you can just try to launch any process by using the
+   native libraries::
+
+      qemu-sparc64 /bin/ls
+
+Command line options
+~~~~~~~~~~~~~~~~~~~~
+
+::
+
+   qemu-sparc64 [-h] [-d] [-L path] [-s size] [-bsd type] program [arguments...]
+
+``-h``
+   Print the help
+
+``-L path``
+   Set the library root path (default=/)
+
+``-s size``
+   Set the stack size in bytes (default=524288)
+
+``-ignore-environment``
+   Start with an empty environment. Without this option, the initial
+   environment is a copy of the caller's environment.
+
+``-E var=value``
+   Set environment var to value.
+
+``-U var``
+   Remove var from the environment.
+
+``-bsd type``
+   Set the type of the emulated BSD Operating system. Valid values are
+   FreeBSD, NetBSD and OpenBSD (default).
+
+Debug options:
+
+``-d item1,...``
+   Activate logging of the specified items (use '-d help' for a list of
+   log items)
+
+``-p pagesize``
+   Act as if the host page size was 'pagesize' bytes
+
+``-singlestep``
+   Run the emulation in single step mode.