qemu.tests: new case to check guest clock with syscall

Signed-off-by: Xu Tian <xutian@redhat.com>
qemu.tests: add timedrift_check_clock_offset cfg

Signed-off-by: Xu Tian <xutian@redhat.com>
qemu.tests: add check clock offset when vm crash/bsod

Signed-off-by: Xu Tian <xutian@redhat.com>
qemu.tests: add cfg for check clock offset when guest bsod/crash

Signed-off-by: Xu Tian <xutian@redhat.com>
qemu.tests: new case to check clock offset after hotplug vcpus

check guest clock drift less that $acceptable_offset after online/offline
hotpluged vcpus;

Signed-off-by: Xu Tian <xutian@redhat.com>
qemu.tests: cfg for checking clock offset after hotplug vcpu

Signed-off-by: Xu Tian <xutian@redhat.com>
qemu.tests: check kvm-clock using newer msr set

Signed-off-by: Xu Tian <xutian@redhat.com>
qemu.tests: cfg for kvm-clock newer msrs support check test

Signed-off-by: Xu Tian <xutian@redhat.com>
Merge pull request #974 from xutian/add_timedrift_case

qemu.tests: new case to check guest clock offset