This reverts commit f0aec23a91368e916a53e6072f2173bb481b1544.

Asias He writes:

  'ip=dhcp' makes kernel try to use nfs as root fs which results in a long
  time 'wait and fail' and finally fallback to 9p as root fs.

  [    1.688000] Sending DHCP requests ., OK
  [    1.695000] IP-Config: Got DHCP answer from 192.168.33.1, my address
  is 192.168.33.15
  [    1.699000] IP-Config: Complete:
  [    1.700000]      device=eth0, addr=192.168.33.15, mask=255.255.255.0,
  gw=192.168.33.1,
  [    1.703000]      host=192.168.33.15, domain=stu.buaa.edu.cn,
  nis-domain=(none),
  [    1.706000]      bootserver=192.168.33.1, rootserver=192.168.33.1,
  rootpath=
  [   36.769000] VFS: Unable to mount root fs via NFS, trying floppy.
  [   36.771000] VFS: Mounted root (9p filesystem) on device 0:14.

As we boot to '/bin/sh' by default, enable kernel DHCP autoconfiguration too.
The guest kernel needs to be configured with the following configuration
options:

  CONFIG_IP_PNP=y
  CONFIG_IP_PNP_DHCP=y

Cc: Asias He <asias.hejun@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Prasad Joshi <prasadjoshi124@gmail.com>
Cc: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

Update required kernel config options and git info.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

Signed-off-by: Emil Renner Berthing <esmil@mailme.dk>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

This patch updates:

- kernel configuration options
- kvm command line options
- authors

in README.

Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>