Multiple MOF GUID's

Multiple MOF GUID's

[Mario.Limonciello]

Andy,

I was looking at a system that will have many more WMI methods, and realizing that I can't 
view the bmof for the extra methods.  This is because of b0e863029 which will show a warning
when multiple of the same WMI GUID's are found.  
The same GUID 05901221-D566-11D1-B2F0-00A0C9062910 is used to describe each one of them.

I think the symlinks in sysfs will break if the warning is just removed.

So what should we do about this?  I think they should both be accessible from the bmof driver from
userspace.


Thanks,

Re: Multiple MOF GUID's

[Andy Lutomirski]

On Fri, Dec 8, 2017 at 11:30 AM,  <Mario.Limonciello@dell.com> wrote:
> Andy,
>
> I was looking at a system that will have many more WMI methods, and realizing that I can't
> view the bmof for the extra methods.  This is because of b0e863029 which will show a warning
> when multiple of the same WMI GUID's are found.
> The same GUID 05901221-D566-11D1-B2F0-00A0C9062910 is used to describe each one of them.

So there are multiple WMI instances, both of which have bmof?

>
> I think the symlinks in sysfs will break if the warning is just removed.
>
> So what should we do about this?  I think they should both be accessible from the bmof driver from
> userspace.

Fixing it will require changing the data structures to get rid of the
global wmi_block_list.  I don't think it'll affect the ABI.  I'll
gladly review a patch ;)

--Andy

RE: Multiple MOF GUID's

[Mario.Limonciello]

> -----Original Message-----
> From: platform-driver-x86-owner@vger.kernel.org [mailto:platform-driver-x86-
> owner@vger.kernel.org] On Behalf Of Andy Lutomirski
> Sent: Friday, December 8, 2017 1:33 PM
> To: Limonciello, Mario <Mario_Limonciello@Dell.com>
> Cc: Platform Driver <platform-driver-x86@vger.kernel.org>
> Subject: Re: Multiple MOF GUID's
> 
> On Fri, Dec 8, 2017 at 11:30 AM,  <Mario.Limonciello@dell.com> wrote:
> > Andy,
> >
> > I was looking at a system that will have many more WMI methods, and realizing
> that I can't
> > view the bmof for the extra methods.  This is because of b0e863029 which will
> show a warning
> > when multiple of the same WMI GUID's are found.
> > The same GUID 05901221-D566-11D1-B2F0-00A0C9062910 is used to describe
> each one of them.
> 
> So there are multiple WMI instances, both of which have bmof?

Yep.

> 
> >
> > I think the symlinks in sysfs will break if the warning is just removed.
> >
> > So what should we do about this?  I think they should both be accessible from the
> bmof driver from
> > userspace.
> 
> Fixing it will require changing the data structures to get rid of the
> global wmi_block_list.  I don't think it'll affect the ABI.  I'll
> gladly review a patch ;)
> 

Alright I'll see what I can do.

RE: Multiple MOF GUID's

[Mario.Limonciello]

> -----Original Message-----
> From: Limonciello, Mario
> Sent: Friday, December 8, 2017 2:05 PM
> To: 'Andy Lutomirski' <luto@kernel.org>
> Cc: Platform Driver <platform-driver-x86@vger.kernel.org>
> Subject: RE: Multiple MOF GUID's
> 
> > -----Original Message-----
> > From: platform-driver-x86-owner@vger.kernel.org [mailto:platform-driver-x86-
> > owner@vger.kernel.org] On Behalf Of Andy Lutomirski
> > Sent: Friday, December 8, 2017 1:33 PM
> > To: Limonciello, Mario <Mario_Limonciello@Dell.com>
> > Cc: Platform Driver <platform-driver-x86@vger.kernel.org>
> > Subject: Re: Multiple MOF GUID's
> >
> > On Fri, Dec 8, 2017 at 11:30 AM,  <Mario.Limonciello@dell.com> wrote:
> > > Andy,
> > >
> > > I was looking at a system that will have many more WMI methods, and realizing
> > that I can't
> > > view the bmof for the extra methods.  This is because of b0e863029 which will
> > show a warning
> > > when multiple of the same WMI GUID's are found.
> > > The same GUID 05901221-D566-11D1-B2F0-00A0C9062910 is used to describe
> > each one of them.
> >
> > So there are multiple WMI instances, both of which have bmof?
> 
> Yep.
> 
> >
> > >
> > > I think the symlinks in sysfs will break if the warning is just removed.
> > >
> > > So what should we do about this?  I think they should both be accessible from
> the
> > bmof driver from
> > > userspace.
> >
> > Fixing it will require changing the data structures to get rid of the
> > global wmi_block_list.  I don't think it'll affect the ABI.  I'll
> > gladly review a patch ;)
> >
> 
> Alright I'll see what I can do.

Oh and btw the case of duplicate GUID's that originally brought that code:
https://github.com/torvalds/linux/commit/d1f9e4970742bb1e22d07b01bd44f9c357d25c42

That's the WMI BMOF GUID 😊

So I won't be too worried about regressions.