Preparing the Environment

Usage Instructions

• StratoVirt can run on VMs with the x86_64 or AArch64 processor architecture.
• You are advised to compile, commission, and deploy StratoVirt on openEuler 21.03.
• 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 the 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
   $ cd kernel
   

2. Run the following command to check and switch the kernel version to 4.19:

   $ git checkout kernel-4.19
   

3. Configure and compile the Linux kernel. It is better to use the recommended configuration file (Obtain configuration file). Copy it to the kernel directory, and rename it as .config. You can also run the following command to configure the kernel 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 bzImzge 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 GiB 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, run the following command:

   $ wget http://dl-cdn.alpinelinux.org/alpine/latest-stable/releases/aarch64/alpine-minirootfs-3.12.0-aarch64.tar.gz
   $ tar -zxvf alpine-minirootfs-3.12.0-aarch64.tar.gz
   $ rm alpine-minirootfs-3.12.0-aarch64.tar.gz
   

   • If the x86_64 processor architecture is used, run the following command:

   $ wget http://dl-cdn.alpinelinux.org/alpine/latest-stable/releases/x86_64/alpine-minirootfs-3.12.0-x86_64.tar.gz
   $ tar -zxvf alpine-minirootfs-3.12.0-x86_64.tar.gz
   $ rm alpine-minirootfs-3.12.0-x86_64.tar.gz
   

5. Run the following command 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. Uninstall 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.