Description of problem:

Check out the number of hits for:
https://www.google.co.uk/search?q="monitor+socket+did+not+show+up"

In the code (src/qemu/qemu_monitor.c) it looks as if the
default timeout is 3 seconds.  I'm not clear if that is 3 seconds
after the fork, 3 seconds after some other qemu event, or what,
but given the number of people who hit this timeout it looks like
this is much too short.

libguestfs hits this bug under load (bug 892273).

Version-Release number of selected component (if applicable):

libvirt from git

How reproducible:

100%

Steps to Reproduce:

  $ cat > /tmp/qemu.wrapper
  #!/bin/sh                                                                     
  sleep 20
  exec qemu-kvm "$@"
  
  $ chmod +x /tmp/qemu.wrapper
  
  $ LIBGUESTFS_QEMU=/tmp/qemu.wrapper libguestfs-test-tool
  [...]
  Original error from libvirt: monitor socket did not show up: No such file or d
irectory [code=38 domain=10]