[ofw] WDK build environment migration thoughts

Mon Apr 21 10:14:56 PDT 2008

Hi all,
I would like to repost my previous message, because I haven't received
yet your comments.
Our regression seems to be stable, so we are going to commit the change
into WinOF trunk the nearest time.
For you convenience, I also provide some typical changes as a patch
(attached to this mail). Please, read the explanation below before - it
will help you a lot.
Be aware that all the modules not contained in Mellanox WinIB stack
(like udapl, vnic) should be also changed according to this methodology.

It is very large change, so I'll appreciate your time and effort while
reviewing the methodology and the patch itself.
Thanks,

Naslednikov Alexander (a.k.a XaleX)
Windows Team
Mellanox Technologies

> _____________________________________________ 
> From: 	Alex Naslednikov  
> Sent:	Thursday, April 10, 2008 4:09 PM
> To:	'Smith, Stan'; Ishai Rabinovitz
> Cc:	ofw at lists.openfabrics.org
> Subject:	RE: [ofw] WDK build environment migration thoughts
> 
> Hi all,
> It's a good idea to clarify some points before announcing Mellanox
> patch for WDK porting and __ptr64 problems.
> Hope, these explanations will be informative enough and not so long.
> 
> 1. __ptr64 problem
> Briefly speaking, this problem arises when copying 32bit len pointer
> into 64bit len pointer. In this case, signed pointer extension will
> take place.
> How it's applicable to WinOF ?  A lot of pointer were declared to be
> __ptr64 (i.e., to be always "long", even in 32bit kernel systems),
> that's to preserve on unique size of structs used in IOCTL calls.  The
> main problem it will cause is between 32bit user applications and
> 64bit kernel application.
> When user code do operation like 
> s_ptr = &my_struct;
> my_type* __ptr64 ptr = s_ptr;
> Than kernel will receive ptr with invalid upper bits data (4 bytes
> FF).
> To avoid signed pointer extension, PtrToPtr64() function should be
> used.
> Also, I found some other places where dangerous signed pointer
> extension took place, even on 32bit kernel.
> Yet another problem that arises with __ptr64 attribute is internal
> compiler error (C1001)  in WDK when using __ptr64 pointer to function
> (callback)
> This problem was described in ofw discussion, you can see also :
> http://blogs.msdn.com/texblog/archive/2005/10/31/487436.aspx
> http://lists.openfabrics.org/pipermail/ofw/2007-July/001613.html
> (posted by Jan from OFW)
> 
> Our solution:
> 1. Initially, we decided to remove all __ptr64 attributes except those
> ones inside IOCTL structures. After, put PtrToPtr64() conversion on
> every assignment to long pointer.
> (like my_type* __ptr64 ptr = PtrToPtr64(s_ptr);  )
> During this solution, we changed a huge amount of code, so patch
> became unreadable. And it was difficult to validate that all long
> pointer (with __ptr64 attribute) were used in a proper manner
> 
> 2. So, we decided about another solution:
>  All __ptr64 occurrences were replaced by either:
>  i) TO_LONG_PTR(type, field) macro, when occurred inside structure
> ii) VOID_PTR64 macro otherwise (defined as void macro)
> 
> #define CONCAT(str1, str2) str1##str2
> 
> #define TO_LONG_PTR(type,member_name) \
>     union { type member_name;  uint64_t CONCAT(member_name,_padding) ;
> }
> 
> Thus, we can both preserve on a uniform shapes of structs in user and
> kernel and to avoid unsafe pointer arithmetic !
> The patch now is much more readable, but it sill consist of thousands
> lines.
> 
> 2. Migration to WDK
> Main issue here was to preserve on backward compatibility with DDK
> We were able to compile our stack with WDK, while the main problems we
> found were :
> 
> 1. WDK uses newer version of SDK (SDK Vista). So, when using 2 or more
> versions of SDK on the same build machine, one has to update 
> PLATFORM_SDK_PATH variable to point on the proper version of SDK (for
> example, PLATFORM_SDK_PATH=%sysdrive%:\PROGRA~1\MI2578~1\windows\v6.1)
> 
> 2.verify.src script in WDK (new add-on) checks if your SOURCES file is
> in appropriate format.
> For example, you can't set implicitly path to system .dll in
> TARGETLIBS, but to use USE_<MODULE_NAME> =1 macro
> Example:
> Old code : 
>  ....
> TARGETLIBS= \
>    $(CRT_LIB_PATH)\msvcprt.lib\
>    $(SDK_LIB_PATH)\Ws2_32.lib\
>    $(TARGETPATH)\*\mtcr.lib
>  
> New code :
> USE_MSVCRT=1
> USE_NTDLL=1
>  
> TARGETLIBS= \
>    $(SDK_LIB_PATH)\Ws2_32.lib\
>    $(TARGETPATH)\*\mtcr.lib
> 
> 3. Some other problems, like mulitple includes error in .rc files, or
> problem with substituing more than one symbol constant into string in
> Makefiles (some version of WDK)
> 
> 
> Currently, we continue testing and will advertise these patches right
> after the testing will finish
> 
> Naslednikov Alexander (a.k.a XaleX)
> Windows Team
> Mellanox Technologies 
> 
> 
> -----Original Message-----
> From: ofw-bounces at lists.openfabrics.org
> [mailto:ofw-bounces at lists.openfabrics.org] On Behalf Of Smith, Stan
> Sent: Tuesday, April 08, 2008 4:10 PM
> To: Ishai Rabinovitz
> Cc: ofw at lists.openfabrics.org
> Subject: [ofw] WDK build environment migration thoughts
> 
> Hello,
>   I strongly believe it would help the WinOF community in
> transitioning to the WDK build environment if the connectX branch
> (svn:gen1\branches\ConnectX) was used as a WDK build environment
> staging grounds prior to merging the WDK modifications into the
> mainline trunk.
> This has been talked about before although it still (as of last
> Friday) does not build using the latest WDK version.
>  
> One week prior to merging the WDK fixes into the mainline trunk, if
> you were to push all the WDK fixes into the ConnectX branch and then
> advertise on the ofw mailing list the availability of a WDK build
> branch along with
> 
>   1) how to build in the WDK environment,
>      which version of the WDK is required + a URL link where to get
> the WDK.
> 
>   2) An explanation of why and how the __ptr64 attributes were removed
> along with how
>      others should correct their codes containing __ptr64 attributes.
> 
>   3) updates to the WinOF wiki page describing how to build in the WDK
> env.
> 
> Let this branch exist for one week, receiving feedback from the list
> and then merge into the mainline trunk.
> 
> Using this approach is certainly community friendly and may prevent
> developer surprises.
> 
> ConnectX branch availability dates plus when the actual WDK fixes
> would be merged into the mainline trunk would be published beforehand.
> 
> 
> Thanks for your consideration,
> 
> Stan.
> 
> 
> 
> _______________________________________________
> ofw mailing list
> ofw at lists.openfabrics.org
> http://lists.openfabrics.org/cgi-bin/mailman/listinfo/ofw
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