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QEMU

tip
  • QEMU 主要用于同架构，TCG 模拟非常慢，以准确为主
# Mac 安装
brew install qemu

# 使用硬件加速启动一个空虚拟机 - 验证是否支持虚拟化
qemu-system-x86_64 -machine accel=kvm

# 显示支持的 accel
qemu-system-x86_64 -accel help

# 生成随机 mac 地址到 macaddr
printf -v macaddr "52:54:%02x:%02x:%02x:%02x" $(( $RANDOM & 0xff)) $(( $RANDOM & 0xff )) $(( $RANDOM & 0xff)) $(( $RANDOM & 0xff ))

random-macaddr(){
  printf "52:54:%02x:%02x:%02x:%02x" $(( $RANDOM & 0xff)) $(( $RANDOM & 0xff )) $(( $RANDOM & 0xff)) $(( $RANDOM & 0xff ))
}

# -netdev tap,id=t0,ifname=en5,script=no,downscript=no -device e1000,netdev=t0,id=nic0,mac=52:54:00:12:34:58
qemu-system-x86_64 -hda vdisk.img -cdrom alpine-standard-3.6.2-x86_64.iso -netdev user,id=en5,net=192.168.8.0/22,dhcpstart=192.168.8.1 -device e1000,netdev=en5,id=nic0,mac=$(random-macaddr)

# 在 macOS 下使用桥接
# 1. 需要在网络偏好中添加一个桥接网络,需要选择物理网卡
# 2. 启动时使用自定义的脚本
qemu-system-x86_64 -smp 2 -vnc :5 -m 1024 -drive file=disk.img,if=virtio -device virtio-balloon -boot c \
  -net nic,model=virtio,macaddr=54:54:00:55:55:55 -net tap,script=../scripts/tap-up,downscript=../scripts/tap-down

# tap-up
TAPDEV="$1"
BRIDGEDEV="bridge0"
ifconfig $BRIDGEDEV addm $TAPDEV

# tap-down
TAPDEV="$1"
BRIDGEDEV="bridge0"
ifconfig $BRIDGEDEV deletem $TAPDEV

# OpenWRT - ARM
# https://wiki.openwrt.org/doc/howto/qemu
# 下载页 https://downloads.openwrt.org/snapshots/trunk/realview/generic/
# 由于没有对应的 PCI 实现, 无法从磁盘等 IDE/SCSI 控制器启动, 但可以从 SD 启动, 只是可能 SD 有大小限制
wget https://downloads.openwrt.org/snapshots/trunk/realview/generic/openwrt-realview-vmlinux-initramfs.elf
qemu-system-arm -M realview-eb-mpcore -kernel openwrt-realview-vmlinux-initramfs.elf -net nic -net user -nographic

# 从 SD 启动
wget https://downloads.openwrt.org/snapshots/trunk/realview/generic/openwrt-realview-vmlinux.elf
wget https://downloads.openwrt.org/snapshots/trunk/realview/generic/openwrt-realview-sdcard.img
qemu-system-arm -M realview-pbx-a9 -m 1024M -nographic \
  -kernel openwrt-realview-vmlinux.elf \
  -sd openwrt-realview-sdcard.img \
  -append "console=ttyAMA0 verbose debug root=/dev/mmcblk0p1"

# Alpine - ARM
tar -zxvf alpine-uboot-3.6.2-armhf.tar.gz -C alpine-uboot-3.6.2-armhf
cd alpine-uboot-3.6.2-armhf
# qemu-system-arm -M vexpress-a9 -kernel zImage -initrd initramfs-grsec -dtb vexpress-v2p-ca9.dtb -hda hda.img -serial stdio
qemu-system-arm -M vexpress-a9 -kernel boot/vmlinuz-hardened \
  -initrd boot/initramfs-hardened -dtb boot/dtbs/vexpress-v2p-ca9.dtb \
  -append "console=ttyAMA0 verbose debug" -nographic

qemu-system-arm -M vexpress-a9 -kernel boot/vmlinuz-hardened \
  -initrd boot/initramfs-hardened -dtb boot/dtbs/vexpress-v2p-ca9.dtb \
  -append "console=ttyAMA0 verbose debug root=/dev/mmcblk0" -nographic

快捷键​

  • M -> 修饰键
    • 默认为 Ctrl+Alt
    • -alt-grab - Ctrl-Alt-Shift
    • -ctrl-grab - 右 Ctrl
快捷键作用
M-f全屏切换
M-+增大屏幕
M--缩小屏幕
M-u恢复屏幕大小
M-n切换为虚拟控制台 'n', 1: 目标系统显示, 2: 监视器, 3: 串口
C-A切换键盘和鼠标捕获
C-a h在 -nographic 显示帮助

特性​

  • 运行模式
    • 全系统模拟
      • 运行任意系统任意架构
    • 用户模式模拟
      • 需要与宿主机架构相同
    • 虚拟化
      • 运行于 KVM 和 XEN
  • 特点
    • 在没有主机驱动的前提下提供可接受的性能
    • 支持多台
    • 提供精确的软件模拟 FPU
  • PC 支持模拟的外设
    • i440FX host PCI bridge and PIIX3 PCI to ISA bridge
    • Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA extensions (hardware level, including all non standard modes).
    • PS/2 mouse and keyboard
    • 2 PCI IDE interfaces with hard disk and CD-ROM support
    • Floppy disk
    • PCI and ISA network adapters
    • Serial ports
    • IPMI BMC, either and internal or external one
    • Creative SoundBlaster 16 sound card
    • ENSONIQ AudioPCI ES1370 sound card
    • Intel 82801AA AC97 Audio compatible sound card
    • Intel HD Audio Controller and HDA codec
    • Adlib (OPL2) - Yamaha YM3812 compatible chip
    • Gravis Ultrasound GF1 sound card
    • CS4231A compatible sound card
    • PCI UHCI, OHCI, EHCI or XHCI USB controller and a virtual USB-1.1 hub.
  • SMP is supported with up to 255 CPUs.

虚拟化说明​

  • x86/x86-64
    • 特性
      • 支持 16/32 为地址段; 支持模拟 LDT/GDT 和 IDT; 支持 VM86 允许 DOSEMU; 部分支持 MMX/3DNow, SSE, SSE2, SSE3, SSE4, x86-64 SVM
      • 用户空间模拟支持主机页文件大于 4k
      • QEMU 支持在 x86 自身模拟
      • 包含部分测试程序 tests/test-i386
    • 限制
      • Limited x86-64 support
      • IPC syscalls are missing
      • The x86 segment limits and access rights are not tested at every memory access (yet). Hopefully, very few OSes seem to rely on that for normal use.
  • ARM
    • 完全支持 ARM7 用户模拟
    • Linux 支持 NWFPE FPU
    • 能运行大部分 ARM Linux 二进制文件