在 ARM 平台上使用 Virtio-Console

[luodeb]

Clone代码

新建一个 clone.sh 文件

#!/bin/bash
BRANCH="-b debin/virtio_dev"
GUEST_BRANCH="-b debin/virtio_guest"

mkdir -p crates

git clone $BRANCH https://github.com/arceos-hypervisor/axvisor.git 

cd axvisor

# 克隆arceos主仓库
git clone $GUEST_BRANCH https://github.com/arceos-hypervisor/arceos.git ../arceos_guest

# 克隆其他仓库到crates目录
REPOS=(
    "arceos"
    "arm_vcpu"
    "axaddrspace"
    "axdevice"
    "axdevice_crates"
    "axvcpu"
    "axvirtio"
    "axvisor_api"
    "axvm"
    "x86_vcpu"
)

for repo in "${REPOS[@]}"; do
    git clone $BRANCH "https://github.com/arceos-hypervisor/${repo}.git" "../crates/${repo}"
done

git clone $BRANCH https://github.com/luodeb/virtio-drivers.git ../crates/virtio-drivers

echo "所有仓库克隆完成！"

cd .. && mkdir .vscode

cat > .vscode/settings.json << 'EOF'
{
    "rust-analyzer.cargo.target": "aarch64-unknown-none-softfloat",
    "rust-analyzer.check.allTargets": false,
    "rust-analyzer.cargo.features": ["irq", "hv"],
    "rust-analyzer.cargo.extraEnv": {
        "RUSTFLAGS": "--cfg platform_family=\"aarch64-qemu-virt\"",
        "AX_CONFIG_PATH": "${workspaceFolder}/axvisor/.axconfig.toml"
    }
}
EOF

使用命令 bash clone.sh 来克隆代码，如果出错得清空文件夹重新克隆

编译Arceos

编译命令以及脚本如下

#!/usr/bin/fish

# 获取参数，默认为 0
set param 0
if test (count $argv) -gt 0
    set param $argv[1]
end

cd ../arceos_guest

# 根据参数选择配置文件
set source_config "configs/platforms/aarch64-qemu-virt_$param.toml"
set target_config "configs/platforms/aarch64-qemu-virt.toml"

# 检查源配置文件是否存在
if not test -f $source_config
    echo "错误: 配置文件 $source_config 不存在"
    exit 1
end

# 复制配置文件
echo "使用配置文件: $source_config"
cp $source_config $target_config

make defconfig ARCH=aarch64
make ARCH=aarch64 SMP=1 A=examples/shell FEATURES=virtio_console BUS=mmio
cp examples/shell/shell_aarch64-qemu-virt.bin ../axvisor/shell_aarch64-qemu-virt_$param.bin
echo "已生成 shell_aarch64-qemu-virt_$param.bin"

编译VM0

首先需要编译第一个 vm，启动地址是在 0x4020_0000

./make_aarch64 0

编译 VM1，启动地址是在 0x8020_0000，这两个 Arcos 只有启动地址不一致，其他的都是一致的

./make_aarch64 1

启动AxVisor

# 创建磁盘文件
make disk_img
# 启动AxVisor
make ACCEL=n ARCH=aarch64 LOG=debug VM_CONFIGS=configs/vms/arceos-aarch64.toml:configs/vms/arceos-aarch64_1.toml FEATURES=hv APP_FEATURES=fs SMP=2 MEM=4G SECOND_SERIAL=y run

# 打开第二个终端
telnet localhost 4321

运行结果

[  0.401525 0 fatfs::dir:139] Is a directory
[  0.409526 0 fatfs::dir:139] Is a directory
[  0.416942 0 fatfs::dir:139] Is a directory
[  0.423362 0 fatfs::dir:139] Is a directory
Available commands:
  cat
  cd
  echo
  exit
  help
  ls
  mkdir
  pwd
  rm
  uname
arceos:/$ ls
drwxr-xr-x     4096 dev
drwxr-xr-x     4096 proc
drwxr-xr-x     4096 sys
drwxr-xr-x     4096 tmp
arceos:/$ ls
drwxr-xr-x     4096 dev
drwxr-xr-x     4096 proc
drwxr-xr-x     4096 sys
drwxr-xr-x     4096 tmp
arceos:/$ mkdir 2222
arceos:/$ ls
ls: command not found
arceos:/$ 
arceos:/$ 
arceos:/$ ls
[ 24.626949 0 fatfs::dir:139] Is a directory
drwxr-xr-x      512 2222
drwxr-xr-x     4096 dev
drwxr-xr-x     4096 proc
drwxr-xr-x     4096 sys
drwxr-xr-x     4096 tmp
arceos:/$

使用 ALT+F1 切换至 VM0，使用 ALT+F2 切换至 VM1

STDIO 后端实现原理

1. 在 arceos 中，实现一个 virtio-console 的前端输出，所有输入输出都通过 virtio 发往后端，后端 virtio-console 接收到数据以后，通过 pl011 将输出发送到 0x904_0000
2. 前端在读取完所有数据以后，主动向后端请求数据，然后后端再从串口中获取数据
3. 默认 pl011 串口绑定 VM0
4. 将所有的输出全部缓存起来，读取快捷键输入，如果检测到快捷键输入，那么正在运行的 VM 取消串口绑定，对应的串口启用绑定，清空屏幕，打印缓存的串口数据