From mboxrd@z Thu Jan 1 00:00:00 1970 From: Subject: RE: RFC: WMI Enhancements Date: Mon, 8 May 2017 15:36:31 +0000 Message-ID: References: <20170419075248.GD18887@pali> <201704191854.51783@pali> <4e3e507b116443298427002c5aafed7f@ausx13mpc120.AMER.DELL.COM> <20170420131431.GM18887@pali> <20170420204436.GC3209@fury> <775ffd8f3327497cabd15ee7826cedaf@ausx13mpc120.AMER.DELL.COM> <20170505234436.GB25865@fury> <20170508152907.GA17700@fury> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20170508152907.GA17700@fury> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: dvhart@infradead.org, luto@kernel.org Cc: pali.rohar@gmail.com, rjw@rjwysocki.net, len.brown@intel.com, corentin.chary@gmail.com, andriy.shevchenko@linux.intel.com, linux-kernel@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-pm@vger.kernel.org List-Id: linux-pm@vger.kernel.org > -----Original Message----- > From: Darren Hart [mailto:dvhart@infradead.org] > Sent: Monday, May 8, 2017 10:29 AM > To: Andy Lutomirski > Cc: Limonciello, Mario ; Pali Roh=E1r > ; Rafael J. Wysocki ; Len Brown > ; Corentin Chary ; Andy > Shevchenko ; linux-kernel@vger.kernel.= org; > platform-driver-x86@vger.kernel.org; linux-pm@vger.kernel.org > Subject: Re: RFC: WMI Enhancements >=20 > On Fri, May 05, 2017 at 06:25:08PM -0700, Andy Lutomirski wrote: > > On Fri, May 5, 2017 at 5:51 PM, wrote: > > >> -----Original Message----- > > >> From: Darren Hart [mailto:dvhart@infradead.org] > > >> Sent: Friday, May 5, 2017 6:45 PM > > >> To: Limonciello, Mario > > >> Cc: pali.rohar@gmail.com; rjw@rjwysocki.net; luto@amacapital.net; > > >> len.brown@intel.com; corentin.chary@gmail.com; luto@kernel.org; > > >> andriy.shevchenko@linux.intel.com; linux-kernel@vger.kernel.org; pla= tform- > > >> driver-x86@vger.kernel.org; linux-pm@vger.kernel.org > > >> Subject: Re: RFC: WMI Enhancements > > > > > > > I meant that to say that at least for now Andy's wmi-mof driver shoul= d still be > merged. > > > If something is going to build on top of this to do WBEM tools, they'= ll need that > MOF > > > data once someone figures out how to nicely deconstruct it. > > > > > > > The thing I don't like about my own driver is that, as a WMI device > > driver, it can be loaded before the rest of the bus finishes probing. > > So user programs that are notified asynchronously that the wmi-mof > > driver is loaded and try to use future functionality (ioctl to issue a > > MOF-based method call?) might end up doing so before the rest of the > > bus is probed. > > > > This could be addressed by always exposing the wmi-mof device last > > (sort of -- it can be a module) or perhaps by moving MOF functionality > > to the core driver. Or maybe it's not really a problem. >=20 > Thanks Andy, I'll keep that in mind and see if I can come up with somethi= ng to > address it while working on WMI this week. >=20 > The other problem with wmi-mof is that there will be no immediate open so= urce > consumers of the interface, and none on the horizon. We can't even test i= t to > any meaningful degree on Linux. I suspect this will be met with stiff > resistance. Well FWIW I did a quick PoC check with the binary that I got out of it to m= ake=20 sure it matched what was supposed to be. I brought it over to a Win10 box = and=20 decompiled using the mofcmp tool and those crazy arguments I mentioned and= =20 it was correct. I'd argue that even if there is no open source tools available today, not m= aking=20 the data available to userspace makes it difficult to even attempt to start= =20 to reverse engineer. Kernel config with default of "N" perhaps for wmi-mof? >=20 > > > > Also, isn't there a way to ask Microsoft to document this? Are you > > supposed to "ask a question" on this forum, perhaps: > > > > https://msdn.microsoft.com/en-us/library/gg134029.aspx > > > > I'm guessing the Samba team knows how to do this, too. > > Microsoft treats this as an "intermediary" format. I'm not convinced that anyone other than MS knows anything about it today. I agree asking them to document it is probably the right way to go.