this feature is used to sample vmexit data per virtual CPU of VM,
command used in HV console as following:
1. vmexit clear : to clear current vmexit buffer
2. vmexit [vm_id] : output vmexit info per-vCPU of one or all VMs
3. vmexit enable | disable, by default enabled
Tracked-On: #5232
Signed-off-by: Minggui Cao <minggui.cao@intel.com>