On Sun, Apr 26, 2020 at 01:02:12PM +0200, Thomas Gleixner wrote: > Fenghua Yu <fenghua...@intel.com> writes: > > s/Add a documentation/Add documentation/ > > > From: Ashok Raj <ashok....@intel.com> > > > > ENQCMD and Data Streaming Accelerator (DSA) and all of their associated > > features are a complicated stack with lots of interconnected pieces. > > This documentation provides a big picture overview for all of the > > features. > > > > Signed-off-by: Ashok Raj <ashok....@intel.com> > > Co-developed-by: Fenghua Yu <fenghua...@intel.com> > > Signed-off-by: Fenghua Yu <fenghua...@intel.com> > > Reviewed-by: Tony Luck <tony.l...@intel.com> > > --- > > Documentation/x86/enqcmd.rst | 185 +++++++++++++++++++++++++++++++++++ > > How is that hooked up into the Documentation index? > > Documentation/x86/enqcmd.rst: WARNING: document isn't included in any toctree > > > +++ b/Documentation/x86/enqcmd.rst > > @@ -0,0 +1,185 @@ > > +.. SPDX-License-Identifier: GPL-2.0 > > + > > +Improved Device Interaction Overview > > So the document is about ENQCMD, right? Can you please make that in some > way consistently named? > > > + > > +== Background == > > This lacks any docbook formatting.... The resulting HTML looks like ... > > > + > > +Shared Virtual Addressing (SVA) allows the processor and device to use the > > +same virtual addresses avoiding the need for software to translate virtual > > +addresses to physical addresses. ENQCMD is a new instruction on Intel > > +platforms that allows user applications to directly notify hardware of new > > +work, much like doorbells are used in some hardware, but carries a payload > > +that carries the PASID and some additional device specific commands > > +along with it. > > Sorry that's not background information, that's an agglomeration of > words. > > Can you please explain properly what's the background of SVA, how it > differs from regular device addressing and what kind of requirements it > has? > > ENQCMD is not related to background. It's part of the new technology. > > > +== Address Space Tagging == > > + > > +A new MSR (MSR_IA32_PASID) allows an application address space to be > > +associated with what the PCIe spec calls a Process Address Space ID > > +(PASID). This PASID tag is carried along with all requests between > > +applications and devices and allows devices to interact with the process > > +address space. > > Sigh. The important part here is not the MSR. The important part is to > explain what PASID is and where it comes from. Documentation has similar > rules as changelogs: > > 1) Provide context > > 2) Explain requirements > > 3) Explain implementation > > The pile you provided is completely backwards and unstructured.
Ok. Will address all of the comments. Thanks. -Fenghua _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
