qemu.tests: fix login test fail when need_install is yes

VM paused after install finished because of option '-no-shutdown', and
env.get_vm() got a paused VM, so case will fail at wait_for_login() when
need_install is 'yes';

Signed-off-by: Xu Tian <xutian@redhat.com>
qemu.test : add some test for cpu_hotplug

Add cpu_hotplug test support in autotest.

Signed-off-by: Yunping Zheng <yunzheng@redhat.com>
virttest.qemu_devices: Support for old qemu ide disks

Older qemu versions (RHEL6) doesn't support ide-hd and ide-cd.
Use ide-drive instead.

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
qemu_cpu.cfg: remove "no 486" line

I don't know why 486 was being excluded, as the CPUID instruction really
works, and QEMU has CPUID data being set for 486, too. The tests keep
working after removing the "no 486" line from the config file.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
qemu.tests: fix some small bugs

1). update pre_command: used scsi_debug parm to add_host instead write
sys filesystem to avoid device create delay;

2). fix passthrough scsi device cache to writethrough to avoid fail to
open /dev/sg* when drive_cache=none; do this because /dev/sg* is
emulated by scsI_debug module, backend of these device is memery, open
with O_DRIECT is not supported;

3). removed useless import module 'qemu_monitor'

Signed-off-by: Xu Tian <xutian@redhat.com>
qemu.tests: Remove useless imported utils_test.

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>
virttest.utils_test: Split huge utils_test module.

With 2000+ lines in utils_test, expanding utils_test will
be not convenient. And to support different types' test(libvirt,
qemu, libguestfs...), now splitting it according its type.

virttest----utils_test
         |
         \--utils_test_lib---general
                           |-qemu---utils_test
                           |-libvirt---utils_test
                           \-...

Just do "import virttest.utils_test" in testcase, then
it will import sub-utils_test according environment
SUB_VIRT_TYPE in control file. If SUB_VIRT_TYPE do not exist,
only general functions will be imported.

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>