I would recommend using the perl vi toolkit (I'm a powershell guy myself), but with perl and the http://<fqdn of virtualcenter>/mod, you should have everything you need to script the changes. Some changes like memory and cpu can be changed online and of course first take effect on reboot, I don't know if the same goes for the cpufeature masking, but it is very likely. So if capable you can write a script that sets all vms cpufeature masking correctly and then it's just planning a restart. I've a powershell script that I use to verify which vms I've set the before mentioned masks on. I only have about 100 vm's, and it took an eternity.
$vms = Get-VM | Sort-Object Name
foreach ($vm in $vms)
{
$views = Get-View $vm.id
foreach ($view in $views)
{
$masks = $view.config.cpuFeatureMask | where-object {$_.Vendor -eq "amd"}
if ($masks.count -ne 5)
{
Write-Host "Error: unexpected number of cpufeature masks, expected 5 got " $masks.count
}
elseif ($masks[1].eax -eq "--
0
" -and $masks[1].ecx -eq "
0
0
0-" -and $masks[3].ecx -eq "--
000000000" -and $masks[3].edx -eq "--
0--
0--
")
{
#Write-Host $vm.Name "CPU masking set"
}
else
{
Write-Host $vm.Name "CPU masking NOT set"
}
}
}
