Project ACRN hypervisor
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Yonghua Huang b4386566ef dm: fix mevent mutex deadlock issue
'mevent_lmutex' is initialized as default type,
 while attempting to recursively lock on this
 kind of mutext results in undefined behaviour.

 Recursively lock on 'mevent_lmutex' can be detected
 in mevent thread when user tries to trigger system
 reset from user VM, in this case, user VM reboot hang.

 The backtrace for this issue:
  #1 in mevent_qlock () at core/mevent.c:93
  #2 in mevent_delete_even at core/mevent.c:357
    ===>Recursively LOCK
  #3 in mevent_delete_close at core/mevent.c:387
  #4 in acrn_timer_deinit at core/timer.c:106
  #5 in virtio_reset_dev at hw/pci/virtio/virtio.c:171
  #6 in virtio_console_reset at
     hw/pci/virtio/virtio_console.c:196
  #7 in virtio_console_destroy at
    hw/pci/virtio/virtio_console.c:1015
  #8 in virtio_console_teardown_backend at
    hw/pci/virtio/virtio_console.c:1042
  #9 in mevent_drain_del_list () at
    core/mevent.c:348 ===> 1st LOCK
  #10 in mevent_dispatch () at core/mevent.c:472
  #11 in main at core/main.c:1110

  So the root cause is:
  mevent_mutex lock is recursively locked by mevent thread
  itself (#9 for this first lock and #2 for recursively lock),
  which is not allowed for mutex with default attribute.

  This patch changes the mutex type of 'mevent_lmutex'
  from default to "PTHREAD_MUTEX_RECURSIVE", because
  recrusively lock shall be allowed as user of mevent
  may call mevent functions (where mutex lock maybe required)
  in teardown callbacks.

Tracked-On: #7133
Signed-off-by: Yonghua Huang <yonghua.huang@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>
2022-02-21 14:23:03 +08:00
.github/ISSUE_TEMPLATE Update bug_report.md 2020-07-23 22:50:26 +08:00
devicemodel dm: fix mevent mutex deadlock issue 2022-02-21 14:23:03 +08:00
doc doc: Style cleanup in doc guides 2022-02-18 20:58:10 -08:00
hypervisor hv: change error code of undefined hypercall 2022-02-21 09:25:50 +08:00
misc config tool: modify ivshmem config for scenario.xml 2022-02-18 18:42:00 +08:00
.checkpatch.conf checkpatch: fix the line limit back to 120 2018-10-29 14:10:22 +08:00
.clang-format config_tools: update clang-format file 2021-06-11 12:59:03 +08:00
.deb.conf deb-pkg: Delete the folder name of acrn-hypervisor in the configuration file 2022-01-24 15:39:51 +08:00
.gitignore config_tools: Update GPU passthrough support 2021-11-02 18:30:54 +08:00
CODE_OF_CONDUCT.rst doc: Add CODE_OF_CONDUCT to project repo 2021-09-22 20:13:58 -07:00
CODEOWNERS Add codeowner 2022-02-18 18:34:29 +08:00
CONTRIBUTING.rst doc: Add TSC and membership documentation 2021-11-29 15:24:23 -08:00
LICENSE doc: update LICENSE copyright years 2020-12-18 15:12:18 +08:00
Makefile deb-pkg: Support specifying board.xml and scenario.xml 2021-12-02 14:40:52 +08:00
paths.make Makefile: put 'serial.conf' in final location 2022-02-18 18:38:45 +08:00
README.rst doc: add community support and resources to introduction 2022-01-26 17:20:08 -08:00
VERSION version:2.8-unstable 2021-12-20 14:24:33 +08:00

Project ACRN Embedded Hypervisor
################################


.. raw:: html

   <img src="doc/images/ACRN_Logo_PrimaryLockup_COLOR-300x300-1.png"
   height="175px" align="right">

The open source project ACRN defines a device hypervisor reference stack
and an architecture for running multiple software subsystems, managed
securely, on a consolidated system by means of a virtual machine
manager. It also defines a reference framework implementation for
virtual device emulation, called the "ACRN Device Model".

The ACRN Hypervisor is a Type 1 reference hypervisor stack, running
directly on the bare-metal hardware, and is suitable for a variety of
IoT and embedded device solutions. The ACRN hypervisor addresses the
gap that currently exists between datacenter hypervisors, and hard
partitioning hypervisors. The ACRN hypervisor architecture partitions
the system into different functional domains, with carefully selected
guest OS sharing optimizations for IoT and embedded devices.

.. start_include_here

Community Support
*****************

The Project ACRN Developer Community includes developers from member
organizations and the general community all joining in the development of
software within the project. Members contribute and discuss ideas,
submit bugs and bug fixes. They also help those in need
through the community's forums such as mailing lists and IRC channels. Anyone
can join the developer community and the community is always willing to help
its members and the User Community to get the most out of Project ACRN.

Welcome to the project ACRN community!

We're now holding monthly Technical Community Meetings and encourage you
to call in and learn more about the project. Meeting information is on
the `TCM Meeting page`_ in our `ACRN wiki <https://wiki.projectacrn.org/>`_.

.. _TCM Meeting page:
   https://github.com/projectacrn/acrn-hypervisor/wiki/ACRN-Committee-and-Working-Group-Meetings#technical-community-meetings

Resources
*********

Here's a quick summary of resources to find your way around the Project
ACRN support systems:

* **Project ACRN Website**: The https://projectacrn.org website is the
  central source of information about the project. On this site, you'll
  find background and current information about the project as well as
  relevant links to project material.  For a quick start, refer to the
  `ACRN Introduction`_ and `Getting Started Guide`_.

* **Source Code in GitHub**: Project ACRN source code is maintained on a
  public GitHub repository at https://github.com/projectacrn/acrn-hypervisor.
  You'll find information about getting access to the repository and how to
  contribute to the project in this `Contribution Guide`_ document.

* **Documentation**: Project technical documentation is developed
  along with the project's code, and can be found at
  https://projectacrn.github.io.  Additional documentation is maintained in
  the `Project ACRN GitHub wiki`_.

* **Issue Reporting and Tracking**: Requirements and Issue tracking is done in
  the Github issues system: https://github.com/projectacrn/acrn-hypervisor/issues.
  You can browse through the reported issues and submit issues of your own.

* **Reporting a Potential Security Vulnerability**: If you have discovered potential
  security vulnerability in ACRN, please send an e-mail to acrn-security@lists.projectacrn.org.

  It is important to include the following details:

  - The projects and versions affected
  - Detailed description of the vulnerability
  - Information on known exploits

* **Mailing List**: The `Project ACRN Development mailing list`_ is perhaps the most convenient
  way to track developer discussions and to ask your own support questions to
  the project ACRN community.  There are also specific `ACRN mailing list
  subgroups`_ for builds, users, and Technical
  Steering Committee notes, for example.
  You can read through the message archives to follow
  past posts and discussions, a good thing to do to discover more about the
  project.


.. _ACRN Introduction: https://projectacrn.github.io/latest/introduction/
.. _Getting Started Guide: https://projectacrn.github.io/latest/getting-started/
.. _Contribution Guide: https://projectacrn.github.io/latest/contribute.html
.. _Project ACRN GitHub wiki: https://github.com/projectacrn/acrn-hypervisor/wiki
.. _PGP Key: https://www.intel.com/content/www/us/en/security-center/pgp-public-key.html
.. _vulnerability handling guidelines:
   https://www.intel.com/content/www/us/en/security-center/vulnerability-handling-guidelines.html
.. _Project ACRN Development mailing list: https://lists.projectacrn.org/g/acrn-dev
.. _ACRN mailing list subgroups: https://lists.projectacrn.org/g/main/subgroups