[vfio-users] VFIO-PCI with AARCH64 QEMU

[Alex Williamson]

On Tue, 25 Oct 2016 21:19:15 +0000
"Haynal, Steve" <Steve_Haynal at mentor.com> wrote:

> Hi Ard,
> 
> Yes, I noted that message in my first e-mail too. I may be able to reduce the size of the region to something that will work on aarch64. But even for another device that has a single small (16kB) memory region, that region shows up as disabled in lspci on aarch64 but not so on x86. There are no drivers in either case. Any ideas on why it shows up as disabled on aarch64?
> 


This was in your original post:

x86:
00:09.0 Memory controller: Xilinx Corporation Device 7022
               Subsystem: Xilinx Corporation Device 0007
               Physical Slot: 9
               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-
               Interrupt: pin A routed to IRQ 10
               Region 0: Memory at e0071000 (32-bit, non-prefetchable) [size=4K]
               Region 1: Memory at c0000000 (32-bit, non-prefetchable) [size=512M]

aarch64:
00:09.0 Memory controller: Xilinx Corporation Device 7022
               Subsystem: Xilinx Corporation Device 0007
               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-
               Interrupt: pin A routed to IRQ 47
               Region 0: Memory at 10000000 (32-bit, non-prefetchable) [disabled] [size=4K]
               Region 1: Memory at <ignored> (32-bit, non-prefetchable) [disabled]

Note the Mem- vs Mem+.  If you flip that with setpci (setpci -s 00:09.0
COMMAND=2:2), it'll show at least BAR0 as enabled.  Maybe it was left
disabled since not all the resources were allocated.