Qemu fork with patch to view PCI communication with HDA chips. Useful when fixing linux/bsd HDA driver for specific devices.
Go to file
Daniel P. Berrangé 4f24430821 doc: document that the monitor console is a privileged control interface
A supposed exploit of QEMU was recently announced as CVE-2019-12928
claiming that the monitor console was insecure because the "migrate"
command enabled arbitrary command execution for a remote attacker.

To be a security risk the user launching QEMU must have configured
the monitor in a way that allows for other users to access it. The
exploit report quoted use of the "tcp" character device backend for
QMP.

This would indeed allow any network user to connect to QEMU and
execute arbitrary commands, however, this is not a flaw in QEMU.
It is the normal expected behaviour of the monitor console and the
commands it supports. Given a monitor connection, there are many
ways to access host file system content besides the migrate command.

The reality is that the monitor console (whether QMP or HMP) is
considered a privileged interface to QEMU and as such must only
be made available to trusted users. IOW, making it available with
no authentication over TCP is simply a, very serious, user
configuration error not a security flaw in QEMU itself.

The one thing this bogus security report highlights though is that
we have not clearly documented the security implications around the
use of the monitor. Add a few paragraphs of text to the security
docs explaining why the monitor is a privileged interface and making
a recommendation to only use the UNIX socket character device backend.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-07-19 14:21:08 +01:00
accel kvm: Support KVM_CLEAR_DIRTY_LOG 2019-07-15 15:39:03 +02:00
audio
authz
backends general: Replace global smp variables with smp machine properties 2019-07-05 17:07:36 -03:00
block * VFIO bugfix for AMD SEV (Alex) 2019-07-16 15:08:29 +01:00
bsd-user
capstone@22ead3e0bf
chardev
contrib rdmacm-mux: fix strcpy string warning 2019-07-15 11:20:42 +02:00
crypto crypto: fix function signatures for nettle 2.7 vs 3 2019-07-19 12:48:22 +01:00
default-configs
disas
docs doc: document that the monitor console is a privileged control interface 2019-07-19 14:21:08 +01:00
dtc@88f18909db
dump
fpu
fsdev
gdb-xml
hw hw/block/pflash_cfi01: Start state machine as READY to accept commands 2019-07-16 17:54:06 +02:00
include linux-user: check valid address in access_ok() 2019-07-18 13:57:28 +02:00
io
libdecnumber
linux-headers
linux-user linux-user: fix to handle variably sized SIOCGSTAMP with new kernels 2019-07-19 09:33:55 +02:00
migration migration: always initial RAMBlock.bmap to 1 for new migration 2019-07-15 15:47:47 +02:00
monitor Fix build error when VNC is configured out 2019-07-15 11:26:26 +01:00
nbd
net
pc-bios pseries: Update SLOF firmware image 2019-07-12 15:49:46 +10:00
po
python/qemu
qapi qmp: Add "alias-of" field to query-cpu-definitions 2019-07-05 17:08:04 -03:00
qga
qobject
qom
replay
roms pseries: Update SLOF firmware image 2019-07-12 15:49:46 +10:00
scripts create_config: remove $(CONFIG_SOFTMMU) hack 2019-07-15 20:58:37 +02:00
scsi iscsi: base all handling of check condition on scsi_sense_to_errno 2019-07-15 11:20:42 +02:00
slirp@f0da672620
stubs
target straighten out some things in the gen15 cpu model 2019-07-16 16:05:42 +01:00
tcg tcg/aarch64: Fix output of extract2 opcodes 2019-07-14 12:19:00 +02:00
tests Block patches for 4.1-rc1: 2019-07-15 16:11:47 +01:00
trace
ui
util * VFIO bugfix for AMD SEV (Alex) 2019-07-16 15:08:29 +01:00
.cirrus.yml
.dir-locals.el
.editorconfig
.exrc
.gdbinit
.gitignore
.gitlab-ci.yml
.gitmodules
.gitpublish
.mailmap
.patchew.yml
.shippable.yml
.travis.yml
arch_init.c
balloon.c
block.c block: Deep-clear inherits_from 2019-07-15 15:48:40 +02:00
blockdev-nbd.c
blockdev.c
blockjob.c
bootdevice.c
bt-host.c
bt-vhci.c
Changelog
CODING_STYLE
configure configure: only link capstone to emulation targets 2019-07-19 12:52:04 +01:00
COPYING
COPYING.LIB
cpus-common.c
cpus.c general: Replace global smp variables with smp machine properties 2019-07-05 17:07:36 -03:00
device-hotplug.c
device_tree.c
disas.c
dma-helpers.c
exec.c memory: Introduce memory listener hook log_clear() 2019-07-15 15:39:02 +02:00
gdbstub.c gdbstub: revert to previous set_reg behaviour 2019-07-10 10:54:46 +01:00
gitdm.config
HACKING
hmp-commands-info.hx
hmp-commands.hx
ioport.c
iothread.c
job-qmp.c
job.c
Kconfig.host
LICENSE
MAINTAINERS MAINTAINERS: update RBD block maintainer 2019-07-08 16:00:26 +02:00
Makefile Makefile: Fix missing dependency of on qemu-tech.texi 2019-07-15 21:10:20 +02:00
Makefile.objs
Makefile.target configure: only link capstone to emulation targets 2019-07-19 12:52:04 +01:00
memory.c * VFIO bugfix for AMD SEV (Alex) 2019-07-16 15:08:29 +01:00
memory_ldst.inc.c
memory_mapping.c
module-common.c
os-posix.c
os-win32.c
qdev-monitor.c
qemu-bridge-helper.c
qemu-deprecated.texi docs: Deprecate CPU model runnability guarantees 2019-07-05 17:08:04 -03:00
qemu-doc.texi
qemu-edid.c
qemu-ga.texi
qemu-img-cmds.hx
qemu-img.c
qemu-img.texi
qemu-io-cmds.c
qemu-io.c
qemu-keymap.c
qemu-nbd.c
qemu-nbd.texi
qemu-option-trace.texi
qemu-options-wrapper.h
qemu-options.h
qemu-options.hx vl.c: Add -smp, dies=* command line support and update doc 2019-07-05 17:08:04 -03:00
qemu-seccomp.c
qemu-tech.texi qemu-tech: Fix dangling @menu entries 2019-07-15 21:10:29 +02:00
qemu.nsi
qemu.sasl
qtest.c
README
replication.c
replication.h
rules.mak
thunk.c
tpm.c
trace-events
VERSION Update version for v4.1.0-rc1 release 2019-07-16 18:01:28 +01:00
version.rc
vl.c vl: make sure char-pty message displayed by moving setbuf to the beginning 2019-07-16 09:27:16 +02:00

         QEMU README
         ===========

QEMU is a generic and open source machine & userspace emulator and
virtualizer.

QEMU is capable of emulating a complete machine in software without any
need for hardware virtualization support. By using dynamic translation,
it achieves very good performance. QEMU can also integrate with the Xen
and KVM hypervisors to provide emulated hardware while allowing the
hypervisor to manage the CPU. With hypervisor support, QEMU can achieve
near native performance for CPUs. When QEMU emulates CPUs directly it is
capable of running operating systems made for one machine (e.g. an ARMv7
board) on a different machine (e.g. an x86_64 PC board).

QEMU is also capable of providing userspace API virtualization for Linux
and BSD kernel interfaces. This allows binaries compiled against one
architecture ABI (e.g. the Linux PPC64 ABI) to be run on a host using a
different architecture ABI (e.g. the Linux x86_64 ABI). This does not
involve any hardware emulation, simply CPU and syscall emulation.

QEMU aims to fit into a variety of use cases. It can be invoked directly
by users wishing to have full control over its behaviour and settings.
It also aims to facilitate integration into higher level management
layers, by providing a stable command line interface and monitor API.
It is commonly invoked indirectly via the libvirt library when using
open source applications such as oVirt, OpenStack and virt-manager.

QEMU as a whole is released under the GNU General Public License,
version 2. For full licensing details, consult the LICENSE file.


Building
========

QEMU is multi-platform software intended to be buildable on all modern
Linux platforms, OS-X, Win32 (via the Mingw64 toolchain) and a variety
of other UNIX targets. The simple steps to build QEMU are:

  mkdir build
  cd build
  ../configure
  make

Additional information can also be found online via the QEMU website:

  https://qemu.org/Hosts/Linux
  https://qemu.org/Hosts/Mac
  https://qemu.org/Hosts/W32


Submitting patches
==================

The QEMU source code is maintained under the GIT version control system.

   git clone https://git.qemu.org/git/qemu.git

When submitting patches, one common approach is to use 'git
format-patch' and/or 'git send-email' to format & send the mail to the
qemu-devel@nongnu.org mailing list. All patches submitted must contain
a 'Signed-off-by' line from the author. Patches should follow the
guidelines set out in the HACKING and CODING_STYLE files.

Additional information on submitting patches can be found online via
the QEMU website

  https://qemu.org/Contribute/SubmitAPatch
  https://qemu.org/Contribute/TrivialPatches

The QEMU website is also maintained under source control.

  git clone https://git.qemu.org/git/qemu-web.git
  https://www.qemu.org/2017/02/04/the-new-qemu-website-is-up/

A 'git-publish' utility was created to make above process less
cumbersome, and is highly recommended for making regular contributions,
or even just for sending consecutive patch series revisions. It also
requires a working 'git send-email' setup, and by default doesn't
automate everything, so you may want to go through the above steps
manually for once.

For installation instructions, please go to

  https://github.com/stefanha/git-publish

The workflow with 'git-publish' is:

  $ git checkout master -b my-feature
  $ # work on new commits, add your 'Signed-off-by' lines to each
  $ git publish

Your patch series will be sent and tagged as my-feature-v1 if you need to refer
back to it in the future.

Sending v2:

  $ git checkout my-feature # same topic branch
  $ # making changes to the commits (using 'git rebase', for example)
  $ git publish

Your patch series will be sent with 'v2' tag in the subject and the git tip
will be tagged as my-feature-v2.

Bug reporting
=============

The QEMU project uses Launchpad as its primary upstream bug tracker. Bugs
found when running code built from QEMU git or upstream released sources
should be reported via:

  https://bugs.launchpad.net/qemu/

If using QEMU via an operating system vendor pre-built binary package, it
is preferable to report bugs to the vendor's own bug tracker first. If
the bug is also known to affect latest upstream code, it can also be
reported via launchpad.

For additional information on bug reporting consult:

  https://qemu.org/Contribute/ReportABug


Contact
=======

The QEMU community can be contacted in a number of ways, with the two
main methods being email and IRC

 - qemu-devel@nongnu.org
   https://lists.nongnu.org/mailman/listinfo/qemu-devel
 - #qemu on irc.oftc.net

Information on additional methods of contacting the community can be
found online via the QEMU website:

  https://qemu.org/Contribute/StartHere

-- End