[dpdk-dev] rte_eth_dev_count() returns 0

[Stephen Hemminger]

On Fri, 10 May 2013 12:10:42 -0700 (PDT)
Bhavesh Davda <bhavesh at vmware.com> wrote:

> Hi Stephen,
> 
> I checked both our hypervisor code and with the experts who wrote and maintain the code, and we don't have any such limitation about not supporting SR-IOV if the motherboard or device doesn't support PCIe ASPM.
> 
> If you can point me to the Intel person(s) who gave you that information (offline, no need to make this public :)), we can make sure such FUD doesn't continue getting spread too far.
> 
> Thanks for making us aware of this FUD though.
> 
> --
> Bhavesh Davda
> 

According to Intel the problem was that the BIOS did not support _OSC table.
SR-IOV needs VT-d enabled and BIOS with _OSC and DMA ACPI tables.
The _OSC table is an ACPI control method that the kernel uses to interact
with PCIe Active Statep Power Management. Linux just assume no  ASPM if table
is missing, VMWare ESX 5.1 seems to need it.