Preparing the Environment

Usage

• StratoVirt can run on VMs with the x86_64 or AArch64 processor architecture.
• You are advised to compile, debug, and deploy StratoVirt on openEuler 22.03 LTS SP2.
• StratoVirt can run with non-root permissions.

Environment Requirements

The following are required in the environment for running StratoVirt:

• /dev/vhost-vsock device (for implementing MMIO)
• nmap tool
• Kernel and rootfs images

Preparing Devices and Tools

• To run StratoVirt, the MMIO device must be implemented. Therefore, before running StratoVirt, ensure that the /dev/vhost-vsock device exists.

  Check whether the device exists.

  $ ls /dev/vhost-vsock
  /dev/vhost-vsock
  

  If the device does not exist, run the following command to generate it:

  modprobe vhost_vsock
  

• To use QMP commands, install the nmap tool first. After configuring the Yum source, run the following command to install the tool:

  # yum install nmap
  

Preparing Images

Creating the Kernel Image

StratoVirt of the current version supports only the PE kernel image of the x86_64 and AArch64 platforms. The kernel image in PE format can be generated by using the following method:

1. Run the following commands to obtain the kernel source code of openEuler:

   git clone https://gitee.com/openeuler/kernel.git
   cd kernel
   

2. Run the following command to check and switch to the kernel version openEuler-22.03-LTS-SP2:

   git checkout openEuler-22.03-LTS-SP2
   

3. Configure and compile the Linux kernel. You are advised to use the recommended configuration file). Copy the file to the kernel directory, rename it to .config, and run the make olddefconfig command to update to the latest default configuration (otherwise, you may need to manually select options for subsequent compilation). Alternatively, you can run the following command to configure the kernel as prompted. The system may display a message indicating that specific dependencies are missing. Run the yum install command to install the dependencies as prompted.

   make menuconfig
   

4. Run the following command to create and convert the kernel image to the PE format. The converted image is vmlinux.bin.

   make -j vmlinux && objcopy -O binary vmlinux vmlinux.bin
   

5. If you want to use the kernel in bzImage format on the x86 platform, run the following command:

   make -j bzImage
   

Creating the Rootfs Image

The rootfs image is a file system image. When StratoVirt is started, the ext4 image with init can be loaded. To create an ext4 rootfs image, perform the following steps:

1. Prepare a file with a proper size (for example, create a file with the size of 10 GB in /home).

   cd /home
   dd if=/dev/zero of=./rootfs.ext4 bs=1G count=10
   

2. Create an empty ext4 file system on this file.

   mkfs.ext4 ./rootfs.ext4
   

3. Mount the file image. Create the /mnt/rootfs directory and mount rootfs.ext4 to the directory as user root.

   $ mkdir /mnt/rootfs
   # Return to the directory where the file system is created, for example, **/home**.
   $ cd /home
   $ sudo mount ./rootfs.ext4 /mnt/rootfs && cd /mnt/rootfs
   

4. Obtain the latest alpine-mini rootfs of the corresponding processor architecture.

   • If the AArch64 processor architecture is used, you can get the latest rootfs from the alpine. For example, alpine-minirootfs-3.16.0-aarch64.tar.gz, the reference commands are as follows:

   wget http://dl-cdn.alpinelinux.org/alpine/latest-stable/releases/aarch64/alpine-minirootfs-3.16.0-aarch64.tar.gz
   tar -zxvf alpine-minirootfs-3.16.0-aarch64.tar.gz
   rm alpine-minirootfs-3.16.0-aarch64.tar.gz
   

   • If the x86_64 processor architecture is used, you can get the latest rootfs from the alpine. For example, alpine-minirootfs-3.16.0-x86_64.tar.gz, the reference commands are as follows:

   wget http://dl-cdn.alpinelinux.org/alpine/latest-stable/releases/x86_64/alpine-minirootfs-3.16.0-x86_64.tar.gz
   tar -zxvf alpine-minirootfs-3.16.0-x86_64.tar.gz
   rm alpine-minirootfs-3.16.0-x86_64.tar.gz
   

5. Run the following commands to create a simple /sbin/init for the ext4 file image:

   $ rm sbin/init; touch sbin/init && cat > sbin/init <<EOF
   #! /bin/sh
   mount -t devtmpfs dev /dev
   mount -t proc proc /proc
   mount -t sysfs sysfs /sys
   ip link set up dev lo
   
   exec /sbin/getty -n -l /bin/sh 115200 /dev/ttyS0
   poweroff -f
   EOF
   
   sudo chmod +x sbin/init
   

6. Unmount the rootfs image.

   cd /home; umount /mnt/rootfs
   

   The rootfs is created successfully. You can use the ext4 rootfs image file rootfs.ext4, which is stored in the /home directory.

Obtaining Firmware Required for Standard Boot

Firmware refers to the device driver stored in a device. An OS can be booted in standard boot mode only through firmware. Currently, StratoVirt supports standard boot based on the Unified Extensible Firmware Interface (UEFI) only in the x86_64 and AArch64 architectures.

EDK II is open source software that implements the UEFI standard. StratoVirt uses EDK II as the standard boot firmware, and therefore you need to obtain the EDK II firmware binary, which can be installed by yum commands.

Run the following command in the x86_64 architecture:

sudo yum install -y edk2-ovmf

Run the following command in the AArch64 architecture:

sudo yum install -y edk2-aarch64

The EDK II firmware binary contains two files: one is used to save executable code, and the other is used to save boot configuration information. After the installation is complete, in the x86_64 architecture, the firmware file OVMF_CODE.fd and firmware configuration file OVMF_VARS.fd are saved in the /usr/share/edk2/ovmf directory. In the AArch64 architecture, the firmware file QEMU_EFI-pflash.raw and firmware configuration file vars-template-pflash.raw are saved in the /usr/share/edk2/aarch64 directory.