Re: [Qemu-devel] [RFC PATCH v3 00/11] qemu-ga: fsfreeze on Windows using VSS

[Stefan Hajnoczi]

On Thu, May 23, 2013 at 03:50:19PM +0200, Paolo Bonzini wrote:
> Il 23/05/2013 15:28, Stefan Hajnoczi ha scritto:
> > On Thu, May 23, 2013 at 3:20 PM, Paolo Bonzini <address@hidden> wrote:
> >> Il 23/05/2013 14:15, Stefan Hajnoczi ha scritto:
> >>> On Tue, May 21, 2013 at 11:33:33AM -0400, Tomoki Sekiyama wrote:
> >>>> * How to build & run qemu-ga with VSS support
> >>>>
> >>>>  - Download Microsoft VSS SDK from:
> >>>>    http://www.microsoft.com/en-us/download/details.aspx?id=23490
> >>>>
> >>>>  - Setup the SDK
> >>>>    scripts/extract-vsssdk-headers setup.exe (on POSIX-systems)
> >>>>
> >>>>  - Specify installed SDK directory to configure option as:
> >>>>    ./configure -with-vss-sdk="path/to/VSS SDK" 
> >>>> --cross-prefix=i686-w64-mingw32-
> >>>
> >>> Are there any plans to make this more developer-friendly?  In the Linux
> >>> world it's unusual to download third-party SDKs; development headers are
> >>> available as packages from the distro.
> >>>
> >>> I haven't looked at the SDK license but hopefully the VSS headers can be
> >>> added to the mingw cross-build toolchain?
> >>
> >> No, the mingw headers are (re)written by hand, or something like that.
> >> The VSS license does not permit redistribution. :/
> > 
> > Can we follow the same process for VSS as for the other mingw headers?
> 
> I have no idea.  Many of them are automatically generated, but some of
> the others have content seemed non-trivial.

Here we go:

"For missing declarations or import functions in the mingw runtime or
w32api it is essential to specify the source of the documentation on
which you based your patch, or to otherwise provide proof that you have
developed your solution through your own experimental effort. Never
resolve an issue by looking at someone else's work (unless it is public
domain). We only accept patches based on publicly available
documentation, (MSDN is an acceptable source, as is any BSD or similarly
licensed source; no GPL or LPGL licensed source is acceptable, unless
your patch relates to a MinGW package which is already distributed under
one of these licences), or on individual experimental effort, and never
based on others' work, (particularly where that work may be
proprietary). Note, in particular, that we adopt a much stricter
standpoint on extracting information from Microsoft's SDK headers, than
that taken by some other projects, such as Wine or ReactOS; consequently
we will always reject, unconditionally, patches based on information
extracted from files published by such projects."

http://www.mingw.org/wiki/SubmitPatches

So basically they reimplement headers by studying MSDN and maybe
experimenting in Visual C++ without peeking at the official SDK.

This would take extra effort.  It would be a nice thing to have in mingw
but is out of scope here.

Stefan