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

[Julien Grall <julien@xxxxxxx>]

Hi Ian,

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.
Cheers,

--
Julien Grall