Re: [PATCH] Add UseConsole parameter to disable default console

[Tu Dinh <ngoc-tu.dinh@xxxxxxxxxx>]

On 26/10/2026 11:43, Owen Smith wrote:
> 
>> On 26/10/2026 11:15, Owen Smith wrote:
>>> By setting "UseConsole" = 1, the default console (and CONSOLE) interface 
>>> will fail.
>>> The default console's PDO will still be created, but any attempt to call 
>>> CreateFile will
>>> fail, so I'd assume any alternate use would need to manage the default 
>>> console ring
>>> itself. Non-default console's PDOs are unaffected.
>>>
>>
>> My idea is to totally prevent xenbus and others from touching the
>> default console ring and leave the console ring's usage to some other
>> applications. That seemed simpler than swallowing read/write requests at
>> first glance.
>>
>>   From my testing, it looks like I can still open handles to the default
>> console PDO XENCONS\VEN_XN&DEV_CONSOLE\0 (e.g. Get-NtFile -Access
>> ReadData,WriteData,Synchronize -ShareMode Delete \Device\...). Although
>> I haven't tested this point further.
>>
> 
> PdoDispatchCreate calls the console's ABI Open, which does not directly call
> the CONSOLE(Acquire) interface, so the PDO can be opened (I missed this)
> The default console's StreamWorker thread will attempt to acquire the console
> interface and fail, skipping any attempt to drive the default console ring.
> StreamPutQueue will allow IRPs to be queued, but nothing will pop them until
> they are cancelled.
> 

I can error handling for StreamWorker to simply error out during 
read/writes. What do you think?

> Owen
> 



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Ngoc Tu Dinh | Vates XCP-ng Developer

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