This example demonstrates how to extend the Bareflank hypervisor to use the APIs for hooking store/load access to the control registers. For more information on how Bareflank extensions work, please see the following:

API Documentation

To setup our extension, run the following (assuming Linux):

cd ~/
git clone https://github.com/Bareflank/hypervisor.git
git clone https://github.com/Bareflank/extended_apis.git
git clone https://github.com/Bareflank/extended_apis_example_control_registers.git
cd ~/hypervisor

./tools/scripts/setup-<xxx>.sh --no-configure
sudo reboot

cd ~/
mkdir build
cd ~/build

~/hypervisor/configure -m ~/hypervisor_example_cr_access_hooks/bin/cr_access_hooks.modules -e ~/hypervisor_example_cr_access_hooks
make

To test out our extended version of Bareflank, all we need to do is run the make shortcuts as usual:

make driver_load
make quick

make status
make dump

make stop
make driver_unload

The debug output should be something like:

DEBUG: enabling mov to cr3 exits

DEBUG: success: host os is now in a vm on vcpuid = 0

DEBUG: enabling mov to cr3 exits

DEBUG: success: host os is now in a vm on vcpuid = 1

DEBUG: cr3 example store callback hook #100; got value: 63a37000

DEBUG: cr3 example store callback hook #c8; got value: 6fab4000

DEBUG: cr3 example load callback hook #3e8; got value: 8fe8f000

DEBUG: cr3 example store callback hook #12c; got value: 8fe8f000

DEBUG: cr3 example store callback hook #190; got value: b5fc3000

DEBUG: cr3 example store callback hook #1f4; got value: 63a61000

DEBUG: cr3 example load callback hook #7d0; got value: 8fe8f000

DEBUG: cr3 example store callback hook #258; got value: 6fb14000