On Mon, Aug 12, 2013 at 4:28 PM, Paul Barrette
<paul.barrette@windriver.com>wrote:

>
> On 08/12/2013 04:19 PM, jinho hwang wrote:
>
> Hi All,
>
> I am using iommu to receive packets both from hypervisor and from VM. KVM
> is used for the virtualization. However, after I deliver the kernel options
> (iommu and pci realloc), I can not receive packets in hypervisor, but VF
> works fine in VM. When I tried to receive packets in hypervisor, dmesg
> shows the following:
>
> ixgbe 0000:03:00.1: complete
> ixgbe 0000:03:00.1: PCI INT A disabled
> igb_uio 0000:03:00.1: PCI INT A -> GSI 38 (level, low) -> IRQ 38
> igb_uio 0000:03:00.1: setting latency timer to 64
> igb_uio 0000:03:00.1: irq 87 for MSI/MSI-X
> uio device registered with irq 57
> DRHD: handling fault status reg 2
> DMAR:[DMA Read] Request device [03:00.1] fault addr *b9d0f000*
>
>
> DMAR:[fault reason 02] Present bit in context entry is clear
>
> 03:00.1 Ethernet controller: Intel Corporation 82599EB 10 Gigabit Dual
> Port Backplane Connection (rev 01)
>         Subsystem: Intel Corporation Ethernet X520 10GbE Dual Port KX4-KR
> Mezz
>         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, Cache Line Size: 64 bytes
>         Interrupt: pin A routed to IRQ 38
>         Region 0: Memory at *d9400000* (64-bit, prefetchable) [size=4M]
>         Region 2: I/O ports at ece0 [size=32]
>         Region 4: Memory at d9bfc000 (64-bit, prefetchable) [size=16K]
>         Expansion ROM at <ignored> [disabled]
>         Capabilities: <access denied>
>         Kernel driver in use: igb_uio
>         Kernel modules: ixgbe
>
> We can see those addresses are not matched. So the kernel got fault. I am
> wondering why this happens?
>
> I have seen this happen when VT-d is enabled in the bios.  If you are
> using dpdk 1.4, add "iommu=pt" to your boot line.  Without it, no packets
> are received.
>
> Pb
>
>
>  One suspicion for this is BIOS. I am currently using BIOS version 3.0,
> but the latest is 6.3.0. Does this affect the matter?
>
>  Any help appreciated!
>
>  Jinho
>
>
>
>
Paul,

thanks. I tried your suggestion, but it works like no iommu command in boot
line. I passed intel_iommu=pt, and receive packets from hypervisor.
However, when I started VM with "-device pci-assign,host=01:00.0", it shows
the following message:

qemu-system-x86_64: -device pci-assign,host=03:10.0: No IOMMU found.
 Unable to assign device "(null)"
qemu-system-x86_64: -device pci-assign,host=03:10.0: Device initialization
failed.
qemu-system-x86_64: -device pci-assign,host=03:10.0: Device
'kvm-pci-assign' could not be initialized

The device is detached from kernel, and move to pci-stub. dmesg does not
show any DMAR fault message anymore.

Any idea?

Jinho