qemu

README

out-of-tree/qemu

Qemu wrapper for kernel-related CI tasks. Supports GNU/Linux and macOS.

Features:

• Uses upstream virtualization -- KVM in GNU/Linux and Hypervisor.framework in macOS.
• Run files and kernel modules directly from local filesystem. No need to copy byself!
• Run commands inside qemu virtual machine at the same way as you run in it locally.

Installation

$ go get code.dumpstack.io/tools/out-of-tree/qemu

Generate root image

First of all we need to generate rootfs for run qemu.

Install qemu and docker

GNU/Linux

$ sudo apt install -y qemu docker

macOS

Note: qemu on macOS since v2.12 (24 April 2018) supports Hypervisor.framework.

$ brew install qemu
$ brew cask install docker

Generate image

$ cd $GOPATH/src/code.dumpstack.io/tools/out-of-tree/tools/qemu-debian-img
$ ./bootstrap.sh

Fill configuration file

$ $EDITOR $GOPATH/src/code.dumpstack.io/tools/out-of-tree/qemu/test.config.go

Run tests

$ go test -v

Usage

$ go get code.dumpstack.io/tools/out-of-tree/qemu

Minimal example:

kernel := qemu.Kernel{
	Name:       "Some kernel name",
	KernelPath: "/path/to/vmlinuz",
	InitrdPath: "/path/to/initrd", // if required
}
q, err := qemu.NewSystem(qemu.X86_64, kernel, "/path/to/qcow2")
if err != nil {
	log.Fatal(err)
}

if err = q.Start(); err != nil {
	log.Fatal(err)
}
defer q.Stop()

output, err = q.Command("root", "echo Hello, World!")
if err != nil {
	log.Fatal(err)
}

// output == "Hello, World!\n"

More information and list of all functions see at go documentation project, or just run locally:

$ godoc code.dumpstack.io/tools/out-of-tree/qemu

Documentation

Index

• Constants
• type Kernel
• type System
  • func NewSystem(arch arch, kernel Kernel, drivePath string) (q *System, err error)
  • func (q System) AsyncCommand(user, cmd string) (err error)
  • func (q System) Command(user, cmd string) (output string, err error)
  • func (q *System) CopyAndInsmod(localKoPath string) (output string, err error)
  • func (q *System) CopyAndRun(user, path string) (output string, err error)
  • func (q *System) CopyFile(user, localPath, remotePath string) (err error)
  • func (q *System) Debug(conn string)
  • func (q *System) GetKASLR() bool
  • func (q *System) GetKPTI() bool
  • func (q *System) GetSMAP() bool
  • func (q *System) GetSMEP() bool
  • func (q System) GetSSHCommand() (cmd string)
  • func (q *System) SetKASLR(state bool)
  • func (q *System) SetKPTI(state bool)
  • func (q *System) SetSMAP(state bool)
  • func (q *System) SetSMEP(state bool)
  • func (q *System) Start() (err error)
  • func (q *System) Stop()

Constants

const (
	// X86x64 is the qemu-system-x86_64
	X86x64 arch = "x86_64"
	// X86x32 is the qemu-system-i386
	X86x32 = "i386"
)

Types

type Kernel

type Kernel struct {
	Name       string
	KernelPath string
	InitrdPath string
}

Kernel describe kernel parameters for qemu

type System

type System struct {
	Cpus   int
	Memory int

	// Timeout works after Start invocation
	Timeout         time.Duration
	KilledByTimeout bool

	KernelPanic bool

	Died bool

	Stdout, Stderr []byte
	// contains filtered or unexported fields
}

System describe qemu parameters and executed process

func NewSystem

func NewSystem(arch arch, kernel Kernel, drivePath string) (q *System, err error)

NewSystem constructor

func (System) AsyncCommand

func (q System) AsyncCommand(user, cmd string) (err error)

AsyncCommand executes command on qemu system but does not wait for exit

func (System) Command

func (q System) Command(user, cmd string) (output string, err error)

Command executes shell commands on qemu system

func (*System) CopyAndInsmod

func (q *System) CopyAndInsmod(localKoPath string) (output string, err error)

CopyAndInsmod copy kernel module to temporary file on qemu then insmod it

func (*System) CopyAndRun

func (q *System) CopyAndRun(user, path string) (output string, err error)

CopyAndRun is copy local file to qemu vm then run it

func (*System) CopyFile

func (q *System) CopyFile(user, localPath, remotePath string) (err error)

CopyFile is copy file from local machine to remote through ssh/scp

func (*System) Debug

func (q *System) Debug(conn string)

Debug is for enable qemu debug and set hostname and port for listen

func (*System) GetKASLR

func (q *System) GetKASLR() bool

GetKASLR is retrieve KASLR settings

func (*System) GetKPTI

func (q *System) GetKPTI() bool

GetKPTI is retrieve KPTI settings

func (*System) GetSMAP

func (q *System) GetSMAP() bool

GetSMAP is retrieve SMAP settings

func (*System) GetSMEP

func (q *System) GetSMEP() bool

GetSMEP is retrieve SMEP settings

func (System) GetSSHCommand

func (q System) GetSSHCommand() (cmd string)

GetSSHCommand returns command for connect to qemu machine over ssh

func (*System) SetKASLR

func (q *System) SetKASLR(state bool)

SetKASLR is changing KASLR state through kernel boot args

func (*System) SetKPTI

func (q *System) SetKPTI(state bool)

SetKPTI is changing KPTI state through kernel boot args

func (*System) SetSMAP

func (q *System) SetSMAP(state bool)

SetSMAP is changing SMAP state through kernel boot args

func (*System) SetSMEP

func (q *System) SetSMEP(state bool)

SetSMEP is changing SMEP state through kernel boot args

func (*System) Start

func (q *System) Start() (err error)

Start qemu process

func (*System) Stop

func (q *System) Stop()

Stop qemu process