Re: [PATCH] SUPPORT.md, MAINTAINERS: De-support qemu-xen-traditional

[Jan Beulich <jbeulich@xxxxxxxx>]

On 14.12.2021 20:19, Julien Grall wrote:
> On 09/12/2021 14:26, Ian Jackson wrote:
>> In 4.16 we changed to not build this by default.  I think it is now
>> time to explicitly desupport it, completely, in favour of Linux dm
>> stub domains.
>>
>> Signed-off-by: Ian Jackson <iwj@xxxxxxxxxxxxxx>
>> ---
>>   MAINTAINERS |  2 +-
>>   SUPPORT.md  | 18 +++++++++---------
>>   2 files changed, 10 insertions(+), 10 deletions(-)
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index e43dc0edce..933579541f 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -455,7 +455,7 @@ S:       Supported
>>   F: tools/python
>>   
>>   QEMU-DM
>> -S:  Supported
>> +S:  Obsolete
>>   T: git https://xenbits.xenproject.org/git-http/qemu-xen-traditional.git
>>   
>>   QEMU UPSTREAM
>> diff --git a/SUPPORT.md b/SUPPORT.md
>> index 3a34933c89..b64ebee93b 100644
>> --- a/SUPPORT.md
>> +++ b/SUPPORT.md
>> @@ -802,17 +802,17 @@ See the section **Blkback** for image formats 
>> supported by QEMU.
>>   ### qemu-xen-traditional ###
>>   
>>   The Xen Project provides an old version of qemu with modifications
>> -which enable use as a device model stub domain.  The old version is
>> -normally selected by default only in a stub dm configuration, but it
>> -can be requested explicitly in other configurations, for example in
>> -`xl` with `device_model_version="QEMU_XEN_TRADITIONAL"`.
>> +which enable use as a device model stub domain.  This old version is
>> +not built by default.  Even if it is build, it is normally selected by
>> +default only in a stub dm configuration, but it can be requested
>> +explicitly in other configurations, for example in `xl` with
>> +`device_model_version="QEMU_XEN_TRADITIONAL"`.
>>   
>> -    Status, Device Model Stub Domains: Supported, with caveats
>> -    Status, as host process device model: No security support, not 
>> recommended
>> +When device model stub domains are desired for the additional
>> +security, we recommend using a device model stub domain consisting of
>> +a modern qemu and a Linux kernel.
> 
> Looking at SUPPORT.md, we have:
> 
> ### Linux device model stubdomains
> 
> Support for running qemu-xen device model in a linux stubdomain.
> 
>      Status: Tech Preview
> 
> Is it still accurate? If yes, I am not sure we can recommend user to 
> switch to Linux stubdomain until this is fully supported.

FWIW I agree that this needs updating at the same time or in a prereq
change. I guess it'll need to be someone other than Ian now to pick
up and progress this patch, though.

Jan