how to use virtual functions on the board in Pcie Bbackplane

Hello Fenghua,

Please provide more information with regards to this design.  What processor are you using?

Is this a TI EVM board, or your own design?  If a TI EVM, which one?

Thank you,

~Leonard  

2 pcs SK-TDA4VM + 1 pcs J721E

2 pcs  SK-TDA4VM + 1 pcs TDA4VM

for example:

  +-------------+                                   +-------------+
   |             |                                   |             |
   |    HOST1    |                                   |    HOST2    |
   |             |                                   |             |
   +------^------+                                   +------^------+
          |                                                 |
          |                                                 |
+---------|-------------------------------------------------|---------+
|  +------v------+                                   +------v------+  |
|  |             |                                   |             |  |
|  |     EP      |                                   |     EP      |  |
|  | CONTROLLER1 |                                   | CONTROLLER2 |  |
|  |             <----------------------------------->             |  |
|  |             |                                   |             |  |
|  |             |                                   |             |  |
|  |             |  SoC With Multiple EP Instances   |             |  |
|  |             |  (Configured using NTB Function)  |             |  |
|  +-------------+                                   +-------------+  |

TDA4VM set EP mode

SK-TDA4VM set RC mode

we can see

./lspci -s 0001:01:00.0 -vvv
0001:01:00.0 Unassigned class [ff00]: Texas Instruments Device b00d
        Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0
        Interrupt: pin A routed to IRQ 492
        Region 0: Memory at 1c7da400 (32-bit, non-prefetchable) [size=256]
        Region 1: Memory at 1c7d9800 (32-bit, non-prefetchable) [size=512]
        Region 2: Memory at 1c7d8000 (32-bit, non-prefetchable) [size=1K]
        Region 3: Memory at 1c7c0000 (32-bit, non-prefetchable) [size=16K]
        Region 4: Memory at 1c700000 (32-bit, non-prefetchable) [size=128K]
        Region 5: Memory at 18100000 (32-bit, non-prefetchable) [size=1M]
        Capabilities: [80] Power Management version 3
                Flags: PMEClk- DSI- D1+ D2- AuxCurrent=0mA PME(D0+,D1+,D2-,D3hot+,D3cold-)
                Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
        Capabilities: [90] MSI: Enable- Count=1/2 Maskable- 64bit+
                Address: 0000000000000000  Data: 0000
        Capabilities: [b0] MSI-X: Enable- Count=2 Masked-
                Vector table: BAR=0 offset=00000080
                PBA: BAR=0 offset=00000090
        Capabilities: [c0] Express (v2) Endpoint, MSI 00
                DevCap: MaxPayload 256 bytes, PhantFunc 0, Latency L0s <1us, L1 <1us
                        ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset+ SlotPowerLimit 0.000W
                DevCtl: CorrErr- NonFatalErr- FatalErr- UnsupReq-
                        RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+ FLReset-
                        MaxPayload 128 bytes, MaxReadReq 512 bytes
                DevSta: CorrErr+ NonFatalErr- FatalErr- UnsupReq- AuxPwr- TransPend-
                LnkCap: Port #0, Speed 8GT/s, Width x2, ASPM L1, Exit Latency L1 <8us
                        ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp+
                LnkCtl: ASPM Disabled; RCB 64 bytes, Disabled- CommClk-
                        ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
                LnkSta: Speed 8GT/s (ok), Width x2 (ok)
                        TrErr- Train- SlotClk- DLActive- BWMgmt- ABWMgmt-
                DevCap2: Completion Timeout: Range B, TimeoutDis+ NROPrPrP- LTR+
                         10BitTagComp+ 10BitTagReq- OBFF Not Supported, ExtFmt+ EETLPPrefix+, MaxEETLPPrefixes 1
                         EmergencyPowerReduction Not Supported, EmergencyPowerReductionInit-
                         FRS- TPHComp- ExtTPHComp-
                         AtomicOpsCap: 32bit- 64bit- 128bitCAS-
                DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis- LTR+ 10BitTagReq- OBFF Disabled,
                         AtomicOpsCtl: ReqEn-
                LnkCap2: Supported Link Speeds: 2.5-8GT/s, Crosslink- Retimer- 2Retimers- DRS-
                LnkCtl2: Target Link Speed: 8GT/s, EnterCompliance- SpeedDis-
                         Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-
                         Compliance De-emphasis: -6dB
                LnkSta2: Current De-emphasis Level: -6dB, EqualizationComplete+ EqualizationPhase1+
                         EqualizationPhase2+ EqualizationPhase3+ LinkEqualizationRequest-
                         Retimer- 2Retimers- CrosslinkRes: unsupported
        Capabilities: [100 v2] Advanced Error Reporting
                UESta:  DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
                UEMsk:  DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
                UESvrt: DLP+ SDES+ TLP- FCP+ CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol-
                CESta:  RxErr+ BadTLP- BadDLLP+ Rollover- Timeout+ AdvNonFatalErr-
                CEMsk:  RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr+
                AERCap: First Error Pointer: 00, ECRCGenCap+ ECRCGenEn- ECRCChkCap+ ECRCChkEn-
                        MultHdrRecCap- MultHdrRecEn- TLPPfxPres- HdrLogCap-
                HeaderLog: 00000000 00000000 00000000 00000000
        Capabilities: [140 v1] Alternative Routing-ID Interpretation (ARI)
                ARICap: MFVC- ACS-, Next Function: 1
                ARICtl: MFVC- ACS-, Function Group: 0
        Capabilities: [150 v1] Device Serial Number 00-00-00-00-00-00-00-00
        Capabilities: [160 v1] Power Budgeting <?>
        Capabilities: [1b8 v1] Latency Tolerance Reporting
                Max snoop latency: 0ns
                Max no snoop latency: 0ns
        Capabilities: [1c0 v1] Dynamic Power Allocation <?>
        Capabilities: [200 v1] Single Root I/O Virtualization (SR-IOV)
                IOVCap: Migration-, Interrupt Message Number: 000
                IOVCtl: Enable- Migration- Interrupt- MSE- ARIHierarchy+
                IOVSta: Migration-
                Initial VFs: 4, Total VFs: 4, Number of VFs: 0, Function Dependency Link: 00
                VF offset: 6, stride: 1, Device ID: 0100
                Supported Page Size: 00000553, System Page Size: 00000010
                Region 0: Memory at 0000000018400000 (64-bit, non-prefetchable)
                VF Migration: offset: 00000000, BIR: 0
        Capabilities: [300 v1] Secondary PCI Express
                LnkCtl3: LnkEquIntrruptEn- PerformEqu-
                LaneErrStat: LaneErr at lane: 0 1
        Capabilities: [400 v1] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
        Capabilities: [440 v1] Process Address Space ID (PASID)
                PASIDCap: Exec+ Priv+, Max PASID Width: 14
                PASIDCtl: Enable- Exec- Priv-
        Capabilities: [4c0 v1] Virtual Channel
                Caps:   LPEVC=0 RefClk=100ns PATEntryBits=1
                Arb:    Fixed- WRR32- WRR64- WRR128-
                Ctrl:   ArbSelect=Fixed
                Status: InProgress-
                VC0:    Caps:   PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-
                        Arb:    Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256-
                        Ctrl:   Enable+ ID=0 ArbSelect=Fixed TC/VC=ff
                        Status: NegoPending- InProgress-
                VC1:    Caps:   PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-
                        Arb:    Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256-
                        Ctrl:   Enable+ ID=1 ArbSelect=Fixed TC/VC=06
                        Status: NegoPending- InProgress-
                VC2:    Caps:   PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-
                        Arb:    Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256-
                        Ctrl:   Enable+ ID=2 ArbSelect=Fixed TC/VC=16
                        Status: NegoPending- InProgress-
                VC3:    Caps:   PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-
                        Arb:    Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256-
                        Ctrl:   Enable+ ID=3 ArbSelect=Fixed TC/VC=22
                        Status: NegoPending- InProgress-
        Capabilities: [5c0 v1] Address Translation Service (ATS)
                ATSCap: Invalidate Queue Depth: 01
                ATSCtl: Enable-, Smallest Translation Unit: 00
        Capabilities: [640 v1] Page Request Interface (PRI)
                PRICtl: Enable- Reset-
                PRISta: RF- UPRGI- Stopped+
                Page Request Capacity: 00000001, Page Request Allocation: 00000000
        Capabilities: [900 v1] L1 PM Substates
                L1SubCap: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1+ L1_PM_Substates+
                          PortCommonModeRestoreTime=255us PortTPowerOnTime=26us
                L1SubCtl1: PCI-PM_L1.2- PCI-PM_L1.1- ASPM_L1.2- ASPM_L1.1-
                           T_CommonMode=0us LTR1.2_Threshold=262144ns
                L1SubCtl2: T_PwrOn=26us
        Capabilities: [a20 v1] Precision Time Measurement
                PTMCap: Requester:+ Responder:- Root:-
                PTMClockGranularity: Unimplemented
                PTMControl: Enabled:- RootSelected:-
                PTMEffectiveGranularity: Unknown
        Kernel driver in use: pci-endpoint-test
        Kernel modules: pci_endpoint_test