Regards Sunil Kumar Kori > -----Original Message----- > From: Xia, Chenbo <chenbo....@intel.com> > Sent: Wednesday, July 13, 2022 12:58 PM > To: Sunil Kumar Kori <sk...@marvell.com>; Ray Kinsella <m...@ashroe.eu> > Cc: dev@dpdk.org; David Marchand <david.march...@redhat.com> > Subject: [EXT] RE: [PATCH 1/2] doc: announce region based device mapping > support > > External Email > > ---------------------------------------------------------------------- > Hi Sunil, > > > -----Original Message----- > > From: Sunil Kumar Kori <sk...@marvell.com> > > Sent: Wednesday, July 13, 2022 3:04 PM > > To: Xia, Chenbo <chenbo....@intel.com>; Ray Kinsella <m...@ashroe.eu> > > Cc: dev@dpdk.org > > Subject: RE: [PATCH 1/2] doc: announce region based device mapping > > support > > > > Hi Chenbo, > > > > There are pci devices which has huge BAR memory but might not be used > > completely. > > Like PCIe device DDR memory is exposed over BAR with 32Gb or so. > > So in that case user might have a requirement to mmap only areas of > > its interest. > > Also avoid wasting of extra memory for each pages when kernel mmaps it. > > This problem statement makes sense to me. About the solution, pls check > below. > > > > > Yes, it is similar to sparse mmap in vfio but I didn't find any > > support in DPDK for sparse mmap. > > So I picked this approach but in either case, ABI change notification > > is needed, Right? > > For ABI, David & I already mentioned in another email that your notice is not > needed anymore. > > What if you send the patchset to support sparse mmap in DPDK, to me, that > seems more generic. Could sparse mmap solve your problem?
I will look into sparse mmap and analyze its feasibility to solve my problem. Will update accordingly. Thanks Chenbo and David. > > Thanks, > Chenbo > > > > > Regards > > Sunil Kumar Kori > > > > > -----Original Message----- > > > From: Xia, Chenbo <chenbo....@intel.com> > > > Sent: Thursday, July 7, 2022 6:09 PM > > > To: Sunil Kumar Kori <sk...@marvell.com>; Ray Kinsella > > > <m...@ashroe.eu> > > > Cc: dev@dpdk.org > > > Subject: [EXT] RE: [PATCH 1/2] doc: announce region based device > > > mapping support > > > > > > External Email > > > > > > -------------------------------------------------------------------- > > > -- > > > Hi Sunil, > > > > > > > -----Original Message----- > > > > From: sk...@marvell.com <sk...@marvell.com> > > > > Sent: Tuesday, June 28, 2022 9:54 PM > > > > To: Ray Kinsella <m...@ashroe.eu> > > > > Cc: dev@dpdk.org; Sunil Kumar Kori <sk...@marvell.com> > > > > Subject: [PATCH 1/2] doc: announce region based device mapping > > > > support > > > > > > > > From: Sunil Kumar Kori <sk...@marvell.com> > > > > > > > > Adding region based device mapping support, which enables pci > > > > device to map only required memory region instead of mapping full > BAR. > > > > > > Why there will be such requirement to mmap only part of BAR when the > > > BAR can be fully mmapped. I thought you want to enable something > > > like sparse mmap feature in VFIO, but seems it's a feature that let > > > driver ask for > > specific > > > mmap option. Could you explain the use case here? > > > > > > Thanks, > > > Chenbo > > > > > > > > > > > Signed-off-by: Sunil Kumar Kori <sk...@marvell.com> > > > > --- > > > > doc/guides/rel_notes/deprecation.rst | 13 +++++++++++++ > > > > 1 file changed, 13 insertions(+) > > > > > > > > diff --git a/doc/guides/rel_notes/deprecation.rst > > > > b/doc/guides/rel_notes/deprecation.rst > > > > index 4e5b23c53d..8800a3eb41 100644 > > > > --- a/doc/guides/rel_notes/deprecation.rst > > > > +++ b/doc/guides/rel_notes/deprecation.rst > > > > @@ -125,3 +125,16 @@ Deprecation Notices > > > > applications should be updated to use the ``dmadev`` library > > instead, > > > > with the underlying HW-functionality being provided by the > > > > ``ioat`` > > or > > > > ``idxd`` dma drivers > > > > + > > > > +* pci: Update ``rte_pci_device`` and ``rte_pci_driver`` to add > > > > +region > > > > based > > > > + memory mapping support. There could be a requirement to mmap > > > > + specific > > > > memory > > > > + region only. Using this mechanism, pci device can be mapped for > > > > + a given BAR at a given offset of given size. > > > > + > > > > + ``rte_pci_device`` will be added with following field > > > > + ``regions[PCI_MAX_RESOURCE][PCI_MAX_REGION_PER_RESOURCE];``. > > > This > > > > + field > > > > will > > > > + specify the regions which are mapped for a given BAR. > > > > + > > > > + ``rte_pci_driver`` will be added with ``rte_pci_region_map > > > > + *regions`` > > > > and > > > > + ``valid_bars[PCI_MAX_RESOURCE]``. Using these fields, driver > > > > + can > > > > propagate > > > > + its region information which are required to be mmap. > > > > -- > > > > 2.25.1
