From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bhavesh Davda <bhavesh-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
Subject: Re: rte_eth_dev_count() returns 0
Date: Fri, 10 May 2013 14:00:00 -0700 (PDT)
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Cc: Henry Wang <wang_hr-YYSg24PYQUdBDgjK7y7TUQ@public.gmane.org>, dev-VfR2kkLFssw@public.gmane.org
To: Stephen Hemminger <stephen-OTpzqLSitTUnbdJkjeBofR2eb7JE58TQ@public.gmane.org>
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> From: "Stephen Hemminger" <stephen-OTpzqLSitTUnbdJkjeBofR2eb7JE58TQ@public.gmane.org>
> Sent: Friday, May 10, 2013 12:29:29 PM
> 
> On Fri, 10 May 2013 12:10:42 -0700 (PDT)
> Bhavesh Davda <bhavesh-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org> 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
> 

Once again, both in looking at our ACPI _OSC code in the hypervisor and in consulting with the experts, there is no such limitation for SR-IOV support in ESXi.

Regards

- Bhavesh