qemu spinning in ___lwp_park50 on XP install

[David Brownlee <abs%absd.org@localhost>]

I'm trying to install XP into qemu-1.3.1 under NetBSD/amd64 6.1 and
qemu invariably becomes unresponsive part way through the install. The
window will still repaint if I move another window over it, but it
will not respond to ^C and ktruss shows a loop of

  7673      3 qemu-system-i386 ___lwp_park50       Err#60 ETIMEDOUT
  7673      3 qemu-system-i386 _lwp_unpark(0x5, 0xdc8878) = 0
  7673      3 qemu-system-i386 __gettimeofday50(0x7f7fd7fffc50, 0) = 0
  7673      5 qemu-system-i386 ___lwp_park50       = 0
  7673      5 qemu-system-i386 ___lwp_park50(0x7f7f9ffffa60, 0,
0xdc8878, 0xdc8878) Err#60 ETIMEDOUT
  7673      5 qemu-system-i386 _lwp_unpark(0x3, 0xdc8878) = 0
  7673      5 qemu-system-i386 __gettimeofday50(0x7f7f9ffffa50, 0) = 0
  7673      3 qemu-system-i386 ___lwp_park50       = 0
  7673      5 qemu-system-i386 ___lwp_park50(0x7f7f9ffffa60, 0,
0xdc8878, 0xdc8878) Err#60 ETIMEDOUT
  7673      5 qemu-system-i386 _lwp_unpark(0x3, 0xdc8878) = 0
  7673      5 qemu-system-i386 __gettimeofday50(0x7f7f9ffffa50, 0) = 0
  7673      3 qemu-system-i386 ___lwp_park50       = 0
  7673      3 qemu-system-i386 ___lwp_park50(0x7f7fd7fffc60, 0,
0xdc8878, 0xdc8878) Err#60 ETIMEDOUT
  7673      3 qemu-system-i386 _lwp_unpark(0x5, 0xdc8878) = 0
  7673      3 qemu-system-i386 __gettimeofday50(0x7f7fd7fffc50, 0) = 0
  7673      5 qemu-system-i386 ___lwp_park50       = 0
  7673      3 qemu-system-i386 ___lwp_park50       Err#60 ETIMEDOUT

The hang sometimes happens when copying driver.cab, or at various
points through during the graphical install (copying files after
configuring network seems to be a favourite).

Has anyone else seen this or anything similar?