Re: MMIO ioremap() error with PCI passthrough

[Andy Burns <lists.xensource.com@adslpipe.co.uk>]

On 01/07/2008 09:30, Keir Fraser wrote:

> What does lspci say the resource areas are for this device? 

Are you asking for anything more than "lspci -vvv" output?

When the card is loaded in dom0 (before I unload the drivers and assign 
the slot to pciback) I see this


08:01.0 Multimedia controller: Philips Semiconductors SAA7130 Video 
Broadcast Decoder (rev 01)
         Subsystem: Compro Technology, Inc. Videomate DVB-T200
         Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- 
ParErr- Stepping- SERR- FastB2B- DisINTx-
         Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium 
 >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
         Latency: 64 (21000ns min, 8000ns max)
         Interrupt: pin A routed to IRQ 17
         Region 0: Memory at febffc00 (32-bit, non-prefetchable) [size=1K]
         Capabilities: [40] Power Management version 1
                 Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA 
PME(D0-,D1-,D2-,D3hot-,D3cold-)
                 Status: D0 PME-Enable- DSel=0 DScale=1 PME-
         Kernel modules: saa7134


When assigned to pciback/pcifront, from within the domU I see this


00:00.0 Multimedia controller: Philips Semiconductors SAA7130 Video 
Broadcast Decoder (rev 01)
         Subsystem: Compro Technology, Inc. Videomate DVB-T200
         Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- 
ParErr- Stepping- SERR- FastB2B-
         Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium 
 >TAbort- <TAbort- <MAbort- >SERR- <PERR-
         Latency: 64 (21000ns min, 8000ns max)
         Interrupt: pin A routed to IRQ 17
         Region 0: Memory at febffc00 (32-bit, non-prefetchable) [size=1K]
         Capabilities: [40] Power Management version 1
                 Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA 
PME(D0-,D1-,D2-,D3hot-,D3cold-)
                 Status: D0 PME-Enable- DSel=0 DScale=1 PME-



> It looks like fec00000 is past the end of the device's mmio region.


Well 0xFEBFFC00 + 1K = 0xFEC00000, is this some sort of off-by-one 
error, where it should only extend to 0xFEBFFFFF?

Is it worth me attempting a change in the driver code from

        dev->lmmio = ioremap(pci_resource_start(pci_dev,0), 0x1000);

to

        dev->lmmio = ioremap(pci_resource_start(pci_dev,0), 0xFFF);