Re: SR-IOV problem with Intel 82599EB (not enough MMIO resources for SR-IOV)

[Yinghai Lu]

On Fri, Nov 9, 2012 at 7:26 AM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote:
> [+ linux-pci, Yinghai]
>
> On Thu, Nov 8, 2012 at 8:59 PM, Jason Gao <pkill.2012@xxxxxxxxx> wrote:
>>> The BIOS in your machine doesn't support SR-IOV.  You'll need to ask the manufacturer for a BIOS upgrade, if in fact one is available.  Sometimes they're not.
>>
>> very thanks Greg,my server Dell R710 with latest BIOS version and
>> option for SR-IOV(SR-IOV Global Enable->Enabled)  opened,I'm confused
>> that Does R710 provide full support for SR-IOV, kernel or  ixgbe
>> driver's bug? but I'm not sure where the problem lies,anyone has any
>> experience about this?   .
>
> Linux normally uses the resource assignments done by the BIOS, but it
> is possible for the kernel to reassign those.  We don't have good
> automatic support for that yet, but on a recent upstream kernel, you
> can try "pci=realloc".  I doubt this option is in CentOS 6.3, though.
>
> If an upstream kernel with "pci=realloc" still doesn't work, please
> post the entire dmesg log.

Even better, upstream kernel will enable realloc automatically if it
finds some SRIOV BAR is not assigned.
related logic is in pci_realloc_detect().

BTW, we may need another patch about realloc.

http://git.kernel.org/?p=linux/kernel/git/yinghai/linux-yinghai.git;a=patch;h=afb9975bddd92b17c2f9859676ce521e2e014997