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vm/vmm: don't start separate process for console

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vmctl console fails from time to time with:

vmctl: console not found

Probably there is some race (most of these things assume
that there is a human typing commands with delays).

Also, vmctl start can connect to console itself with -c flag.
So use that because it both solves the console race and
also makes code much more similar to other VM implementations (qemu, gvisor).
This also eliminates 3 additional goroutines per VM.
This commit is contained in:
Dmitry Vyukov 2018-09-19 18:33:47 +02:00
parent 23db2ea6f9
commit 565a5452a1
1 changed files with 61 additions and 99 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

160
vm/vmm/vmm.go
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@ -8,6 +8,7 @@ import (
"fmt"
"io"
"os"
"os/exec"
"path/filepath"
"regexp"
"strings"
@ -37,19 +38,17 @@ type Pool struct {
type instance struct {
cfg *Config
index int
image string
debug bool
os string
workdir string
sshkey string
sshuser string
sshhost string
sshport int
merger *vmimpl.OutputMerger
vmName string
stop chan bool
diagnose chan string
vmm *exec.Cmd
consolew io.WriteCloser
}
var ipRegex = regexp.MustCompile(`bound to (([0-9]+\.){3}3)`)
@ -100,21 +99,22 @@ func (pool *Pool) Create(workdir string, index int) (vmimpl.Instance, error) {
return nil, err
}
name := fmt.Sprintf("%v-%v", pool.env.Name, index)
inst := &instance{
cfg: pool.cfg,
index: index,
image: image,
debug: pool.env.Debug,
os: pool.env.OS,
workdir: workdir,
sshkey: pool.env.SSHKey,
sshuser: pool.env.SSHUser,
sshport: 22,
vmName: name,
stop: make(chan bool),
diagnose: make(chan string),
var tee io.Writer
if pool.env.Debug {
tee = os.Stdout
}
inst := &instance{
cfg: pool.cfg,
image: image,
debug: pool.env.Debug,
os: pool.env.OS,
sshkey: pool.env.SSHKey,
sshuser: pool.env.SSHUser,
sshport: 22,
vmName: fmt.Sprintf("%v-%v", pool.env.Name, index),
merger: vmimpl.NewOutputMerger(tee),
}
inst.vmctl("stop", inst.vmName, "-f", "-w") // in case it's still running from the previous run
closeInst := inst
defer func() {
@ -132,30 +132,46 @@ func (pool *Pool) Create(workdir string, index int) (vmimpl.Instance, error) {
}
func (inst *instance) Boot() error {
mem := fmt.Sprintf("%vM", inst.cfg.Mem)
outr, outw, err := osutil.LongPipe()
if err != nil {
return err
}
inr, inw, err := osutil.LongPipe()
if err != nil {
outr.Close()
outw.Close()
return err
}
startArgs := []string{
"start", inst.vmName,
"-b", inst.cfg.Kernel,
"-d", inst.image,
"-m", mem,
"-m", fmt.Sprintf("%vM", inst.cfg.Mem),
"-L", // add a local network interface
"-c", // connect to the console
}
if inst.cfg.Template != "" {
startArgs = append(startArgs, "-t", inst.cfg.Template)
}
if _, err := inst.vmctl(startArgs...); err != nil {
return err
}
var tee io.Writer
if inst.debug {
tee = os.Stdout
log.Logf(0, "running command: vmctl %#v", startArgs)
}
inst.merger = vmimpl.NewOutputMerger(tee)
if err := inst.console(); err != nil {
cmd := osutil.Command("vmctl", startArgs...)
cmd.Stdin = inr
cmd.Stdout = outw
cmd.Stderr = outw
if err := cmd.Start(); err != nil {
outr.Close()
outw.Close()
inr.Close()
inw.Close()
return err
}
inst.vmm = cmd
inst.consolew = inw
outw.Close()
inr.Close()
inst.merger.Add("console", outr)
var bootOutput []byte
bootOutputStop := make(chan bool)
@ -202,6 +218,14 @@ func (inst *instance) Boot() error {
func (inst *instance) Close() {
inst.vmctl("stop", inst.vmName, "-f")
if inst.consolew != nil {
inst.consolew.Close()
}
if inst.vmm != nil {
inst.vmm.Process.Kill()
inst.vmm.Wait()
}
inst.merger.Wait()
}
func (inst *instance) Forward(port int) (string, error) {
@ -264,95 +288,33 @@ func (inst *instance) Run(timeout time.Duration, stop <-chan bool, command strin
signal(vmimpl.ErrTimeout)
case err := <-inst.merger.Err:
cmd.Process.Kill()
inst.stop <- true
inst.merger.Wait()
if cmdErr := cmd.Wait(); cmdErr == nil {
// If the command exited successfully, we got EOF error from merger.
// But in this case no error has happened and the EOF is expected.
err = nil
}
signal(err)
return
}
cmd.Process.Kill()
inst.stop <- true
inst.merger.Wait()
cmd.Wait()
}()
return inst.merger.Output, errc, nil
}
func (inst *instance) Diagnose() bool {
commands := []string{"", "trace", "show registers"}
for _, c := range commands {
select {
case inst.diagnose <- c:
case <-time.After(5 * time.Second):
}
// TODO(dvyukov): this does not work because console asks for login:
// OpenBSD/amd64 (syzkaller.my.domain) (tty00)
// login: trace
// Password:
// Login incorrect
for _, c := range []string{"\n", "trace\n", "show registers\n"} {
inst.consolew.Write([]byte(c))
time.Sleep(1 * time.Second)
}
return true
}
func (inst *instance) console() error {
outr, outw, err := osutil.LongPipe()
if err != nil {
return err
}
inr, inw, err := osutil.LongPipe()
if err != nil {
outr.Close()
outw.Close()
return err
}
cmd := osutil.Command("vmctl", "console", inst.vmName)
cmd.Stdin = inr
cmd.Stdout = outw
cmd.Stderr = outw
if err := cmd.Start(); err != nil {
outr.Close()
outw.Close()
inr.Close()
inw.Close()
return err
}
outw.Close()
inr.Close()
inst.merger.Add("console", outr)
go func() {
stopDiagnose := make(chan bool)
go func() {
for {
select {
case s := <-inst.diagnose:
inw.Write([]byte(s + "\n"))
time.Sleep(1 * time.Second)
case <-stopDiagnose:
return
}
}
}()
stopProcess := make(chan bool)
go func() {
select {
case <-inst.stop:
cmd.Process.Kill()
case <-stopProcess:
}
}()
_, err = cmd.Process.Wait()
inw.Close()
stopDiagnose <- true
stopProcess <- true
}()
return nil
}
// Run the given vmctl(8) command and wait for it to finish.
func (inst *instance) vmctl(args ...string) (string, error) {
if inst.debug {