[Qemu-devel] [PULL 2/4] qemu-tech.texi: Remove "QEMU compared to other emulators" section

[Peter Maydell <peter.maydell@linaro.org>]

The "QEMU compared to other emulators" section of our documentation
hasn't been updated since 2015 (and parts of the text are even older).
We're clearly not very well placed to track the evolution of a
dozen other emulation projects, and an inaccurate or out of date
comparison doesn't serve anybody, so we're best off just removing
the whole documentation section.

If anybody cares strongly about maintaining a comparison page,
it's probably better to do that on the project's wiki where
we can update it more dynamically.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190607152827.18003-3-peter.maydell@linaro.org
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qemu-tech.texi | 107 -------------------------------------------------
 1 file changed, 107 deletions(-)

diff --git a/qemu-tech.texi b/qemu-tech.texi
index eb430daacf2..3451cfaa5be 100644
--- a/qemu-tech.texi
+++ b/qemu-tech.texi
@@ -161,57 +161,6 @@ may be created from overlay with minimal amount of hand-written code.
 
 @end itemize
 
-@node QEMU compared to other emulators
-@section QEMU compared to other emulators
-
-Like bochs [1], QEMU emulates an x86 CPU. But QEMU is much faster than
-bochs as it uses dynamic compilation. Bochs is closely tied to x86 PC
-emulation while QEMU can emulate several processors.
-
-Like Valgrind [2], QEMU does user space emulation and dynamic
-translation. Valgrind is mainly a memory debugger while QEMU has no
-support for it (QEMU could be used to detect out of bound memory
-accesses as Valgrind, but it has no support to track uninitialised data
-as Valgrind does). The Valgrind dynamic translator generates better code
-than QEMU (in particular it does register allocation) but it is closely
-tied to an x86 host and target and has no support for precise exceptions
-and system emulation.
-
-EM86 [3] is the closest project to user space QEMU (and QEMU still uses
-some of its code, in particular the ELF file loader). EM86 was limited
-to an alpha host and used a proprietary and slow interpreter (the
-interpreter part of the FX!32 Digital Win32 code translator [4]).
-
-TWIN from Willows Software was a Windows API emulator like Wine. It is less
-accurate than Wine but includes a protected mode x86 interpreter to launch
-x86 Windows executables. Such an approach has greater potential because most
-of the Windows API is executed natively but it is far more difficult to
-develop because all the data structures and function parameters exchanged
-between the API and the x86 code must be converted.
-
-User mode Linux [5] was the only solution before QEMU to launch a
-Linux kernel as a process while not needing any host kernel
-patches. However, user mode Linux requires heavy kernel patches while
-QEMU accepts unpatched Linux kernels. The price to pay is that QEMU is
-slower.
-
-The Plex86 [6] PC virtualizer is done in the same spirit as the now
-obsolete qemu-fast system emulator. It requires a patched Linux kernel
-to work (you cannot launch the same kernel on your PC), but the
-patches are really small. As it is a PC virtualizer (no emulation is
-done except for some privileged instructions), it has the potential of
-being faster than QEMU. The downside is that a complicated (and
-potentially unsafe) host kernel patch is needed.
-
-The commercial PC Virtualizers (VMWare [7], VirtualPC [8]) are faster
-than QEMU (without virtualization), but they all need specific, proprietary
-and potentially unsafe host drivers. Moreover, they are unable to
-provide cycle exact simulation as an emulator can.
-
-VirtualBox [9], Xen [10] and KVM [11] are based on QEMU. QEMU-SystemC
-[12] uses QEMU to simulate a system where some hardware devices are
-developed in SystemC.
-
 @node Managed start up options
 @section Managed start up options
 
@@ -247,59 +196,3 @@ depend on an initialized machine, including but not limited to:
 @item query-status
 @item x-exit-preconfig
 @end table
-
-@node Bibliography
-@section Bibliography
-
-@table @asis
-
-@item [1]
-@url{http://bochs.sourceforge.net/}, the Bochs IA-32 Emulator Project,
-by Kevin Lawton et al.
-
-@item [2]
-@url{http://www.valgrind.org/}, Valgrind, an open-source memory debugger
-for GNU/Linux.
-
-@item [3]
-@url{http://ftp.dreamtime.org/pub/linux/Linux-Alpha/em86/v0.2/docs/em86.html},
-the EM86 x86 emulator on Alpha-Linux.
-
-@item [4]
-@url{http://www.usenix.org/publications/library/proceedings/usenix-nt97/@/full_papers/chernoff/chernoff.pdf},
-DIGITAL FX!32: Running 32-Bit x86 Applications on Alpha NT, by Anton
-Chernoff and Ray Hookway.
-
-@item [5]
-@url{http://user-mode-linux.sourceforge.net/},
-The User-mode Linux Kernel.
-
-@item [6]
-@url{http://www.plex86.org/},
-The new Plex86 project.
-
-@item [7]
-@url{http://www.vmware.com/},
-The VMWare PC virtualizer.
-
-@item [8]
-@url{https://www.microsoft.com/download/details.aspx?id=3702},
-The VirtualPC PC virtualizer.
-
-@item [9]
-@url{http://virtualbox.org/},
-The VirtualBox PC virtualizer.
-
-@item [10]
-@url{http://www.xen.org/},
-The Xen hypervisor.
-
-@item [11]
-@url{http://www.linux-kvm.org/},
-Kernel Based Virtual Machine (KVM).
-
-@item [12]
-@url{http://www.greensocs.com/projects/QEMUSystemC},
-QEMU-SystemC, a hardware co-simulator.
-
-@end table
-- 
2.20.1