60 lines
1.8 KiB
ReStructuredText
60 lines
1.8 KiB
ReStructuredText
.. _split-device-model:
|
|
|
|
Split Device Model
|
|
==================
|
|
|
|
We usually emulate devices in the Device Model. However, in some cases, we
|
|
need to emulate devices in the ACRN Hypervisor. For example, the
|
|
post-launched RTVM needs to emulate passthrough PCI(e) devices in the ACRN
|
|
Hypervisor so that it can continue to run even if the Device Model is
|
|
no longer working. Nevertheless, the Device Model still owns the overall
|
|
resource management such as memory/MMIO space and interrupt pins.
|
|
|
|
One communication method provided by the ACRN Hypervisor aligns the resource information for the Device Model with the ACRN Hypervisor emulated device.
|
|
|
|
Let's take the passthrough PCI(e) device as an example. Before we split
|
|
passthrough PCI(e) devices from the Device Model to the ACRN Hypervisor, the
|
|
whole picture looks like this:
|
|
|
|
.. figure:: images/split-dm-image1.png
|
|
:align: center
|
|
:width: 900px
|
|
:name: split-dm-architecture-overview1
|
|
|
|
PCI Config space access in the Service VM or Pre-launched VM
|
|
|
|
.. figure:: images/split-dm-image2.png
|
|
:align: center
|
|
:width: 900px
|
|
:name: split-dm-architecture-overview2
|
|
|
|
PCI Config space access in the Post-launched VM
|
|
|
|
After we split passthrough PCI(e) devices from the Device Model to the
|
|
ACRN Hypervisor, the whole picture looks like this:
|
|
|
|
.. figure:: images/split-dm-image3.png
|
|
:align: center
|
|
:width: 900px
|
|
:name: split-dm-architecture-overview3
|
|
|
|
.. figure:: images/split-dm-image4.png
|
|
:align: center
|
|
:width: 900px
|
|
:name: split-dm-architecture-overview4
|
|
|
|
PCI Config space access in the Post-launched VM
|
|
|
|
Interfaces Design
|
|
=================
|
|
|
|
In order to achieve this, we have added a new pair of hypercalls to align
|
|
the PCI(e) BAR and INTx information.
|
|
|
|
.. doxygenfunction:: hcall_assign_pcidev
|
|
:project: Project ACRN
|
|
|
|
.. doxygenfunction:: hcall_deassign_pcidev
|
|
:project: Project ACRN
|
|
|