[libvirt] [PATCH v4 4/8] libxl: do not enable nested HVM unless global nested_hvm option enabled

[Jim Fehlig]

On 02/26/2018 04:10 PM, Marek Marczykowski-Górecki wrote:
> On Mon, Feb 26, 2018 at 03:47:11PM -0700, Jim Fehlig wrote:
>> On 02/08/2018 03:58 PM, Marek Marczykowski-Górecki wrote:
>>> +
>>> +# Nested HVM global control. In order to use nested HVM feature, this option
>>> +# needs to be enabled, in addition to specifying <cpu mode='host-passthrough'>
>>> +# in domain configuration.
>>> +# By default it is disabled.
>>> +#nested_hvm = 0
>>
>> I think per-domain settings should override this one. Users would find it
>> odd that they don't have vmx in their hvm guest with
>>
>>    <cpu mode='host-passthrough'>
>>      <feature policy='require' name='vmx'/>
>>    </cpu>
> 
> I like this one :) It means that by just introducing global
> "nested_hvm = 0", we can have what I've originally proposed - nested HVM
> disabled until explicitly enabled with exactly this config snippet.

Yes. Sorry if we've been going around in circles on some of these topics.

> This change would require adjusting the comment for the option that it's
> only about default value, not really global switch.

Nod.

Regards,
Jim