README.md

djournalplus.code

DJPLUS: High-performance data journaling

Setting environment variables

source set_env.sh

Get the submodule source code

git submodule update --recursive --init

Compile Kernel

Develop data journal modules (jbd2) in kernel code. Modify code and build on host. Then reboot on QEMU. HIGHLY recommend you to use gcc-9 (gcc-13 makes compile error)

cp ./VM_kernel.config ./djournalplus-kernel.code/.config
cd ./djournal-kernel.code
make menuconfig # Optional
make -j
sudo make modules_install
sudo make install

PCIe Passthrough to QEMU

Before setting Passthrough, check memlock of user by following command

ulimit -l

If it is not "unlimited" then modify "/etc/security/limits.conf" file.

For example add follow lines to the file. jhlee soft memlock unlimited jhlee hard memlock unlimited

Then applying the changes

sudo systemctl restart systemd-logind

After checking memlock, follow below steps

1. Enable Vt-d at BIOS setup

2. Make host Linux to use IOMMU

1. Add intel_iommu=on to GRUB_CMDLINE_LINUX_DEFAULT variable in /etc/default/grub file.
2. sudo update-grub
3. Reboot the host machine.
4. Check IOMMU has been activated with dmesg | grep DMAR.

3. Enable Vt-d at BIOS setup

SPDK repo will be used only for PCIe Passthrough setting. DO NOT build SPDK on host machine.

cd ./spdk
sudo ./scripts/setup.sh

You may see "0000:86:00.0 (144d a824): nvme -> vfio-pci" 86.00.0 will be PCIe address of NVMe drive, used in QEMU

You can reset PCIe passthrough

cd ./spdk
sudo ./scripts/setup.sh reset

QEMU/GDB setting

Refer to README file in qemu directory.