Windows 8 / Server 2012 Filter Driver 'SupportedFeatures' registry entry

NTFSD
1

The new Offload support (FSCTL_OFFLOAD_READ/_WRITE) requires a FD to
indicate it supports this by setting the SupportedFeatures registry
entry. Couple of questions…

Am I correct in thinking I need to set the value of this to 3 to show
support for both the FSCTLs?

Where does the key go? Along with Altitude and Flags in the instance, or
with DisplayName and Description in the services section?

Thanks,
John

2

“John Leonard” wrote in message news:xxxxx@ntfsd…

Am I correct in thinking I need to set the value of this to 3 to show
support for both the FSCTLs?

That’s my understanding (see the SUPPORTED_FS_FEATURES_OFFLOAD_READ/_WRITE
values in the preview WDK ntifs.h)

Where does the key go? Along with Altitude and Flags in the instance, or
with DisplayName and Description in the services section?

The Win8 mini-filter samples set this value, so you can use those as a
reference. For example, the latest MiniSpy is available here:

http://code.msdn.microsoft.com/windowshardware/Minispy-File-System-97844844

;
; Registry Modifications
;

[Minispy.AddRegistry]
HKR,“SupportedFeatures”,0x00010001,0x3
HKR,“Instances”,“DefaultInstance”,0x00000000,%DefaultInstance%
…

-scott

–
Scott Noone
Consulting Associate and Chief System Problem Analyst
OSR Open Systems Resources, Inc.
http://www.osronline.com

“John Leonard” wrote in message news:xxxxx@ntfsd…

The new Offload support (FSCTL_OFFLOAD_READ/_WRITE) requires a FD to
indicate it supports this by setting the SupportedFeatures registry
entry. Couple of questions…

Am I correct in thinking I need to set the value of this to 3 to show
support for both the FSCTLs?

Where does the key go? Along with Altitude and Flags in the instance, or
with DisplayName and Description in the services section?

Thanks,
John

3

Thanks for the pointer to the Minispy example - just what was needed!

  • John

On 18/07/2012 15:26, Scott Noone wrote:

“John Leonard” wrote in message news:xxxxx@ntfsd…
> Am I correct in thinking I need to set the value of this to 3 to show
> support for both the FSCTLs?

That’s my understanding (see the
SUPPORTED_FS_FEATURES_OFFLOAD_READ/_WRITE values in the preview WDK
ntifs.h)

> Where does the key go? Along with Altitude and Flags in the instance,
> or with DisplayName and Description in the services section?

The Win8 mini-filter samples set this value, so you can use those as a
reference. For example, the latest MiniSpy is available here:

http://code.msdn.microsoft.com/windowshardware/Minispy-File-System-97844844

;
; Registry Modifications
;

[Minispy.AddRegistry]
HKR,“SupportedFeatures”,0x00010001,0x3
HKR,“Instances”,“DefaultInstance”,0x00000000,%DefaultInstance%
…

-scott