Files
acrn-hypervisor/devicemodel
Liu Shuo A fa7f6c2c83 dm: fix deadlock between emulate_mem and un/register_mem
There is a deadlock when emulate_mem is called on the memory region
of PCI extended configuration space. The call trace is something like:
    emulate_mem
 -> pci_emul_ecfg_handler
 -> pci_cfgrw
 -> pci_emul_cmdsts_write
 -> unregister_bar/register_bar
 -> modify_bar_registration
 -> unregister_mem/register_mem

mmio_rwlock is hold in emulate_mem when calling unregister_mem/
register_mem which is trying to acquire mmio_rwlock again, and deadlock
happened.

It is possible that bar address is changed just between a on-going
MMIO access which can bring a race condition in theroy. Guest needs to
take care of the serial operation between bar addess update and MMIO
access of that bar.

Tracked-On: #2962
Signed-off-by: Yu Wang <yu1.wang@intel.com>
Signed-off-by: Jian Jun Chen <jian.jun.chen@intel.com>
Signed-off-by: Liu Shuo A <shuo.a.liu@intel.com>
Acked-by: Yin Fengwei <fengwei.yin@intel.com>
2019-04-16 15:03:04 +08:00
..
2019-04-01 12:39:42 +08:00
2019-04-11 13:21:30 +08:00
2018-05-15 17:19:39 +08:00
2019-03-26 00:21:52 -07:00

ACRN Device Model
#################

Introduction
============
The ACRN Device Model provides **device sharing** capabilities between the
Service OS and Guest OSs. It is a component that is used in conjunction with
the `ACRN Hypervisor`_ and this is installed within the Service OS. You can
find out more about Project ACRN on the `Project ACRN documentation`_ website.

.. _`ACRN Hypervisor`: https://github.com/projectacrn/acrn-hypervisor
.. _`Project ACRN documentation`: https://projectacrn.github.io/