On 30/07/14 19:05, Don Dutile wrote: > On 07/30/2014 01:16 PM, Edward Cree wrote: >> Calling pci_sriov_set_totalvfs(dev, 0) has no effect, because >> pci_sriov_get_totalvfs ignores dev->sriov->driver_max_VFs if it's 0, >> as that is used as the 'not set' value. >> So, three questions: >> a) is this a bug? >> b) if not, should the comment on pci_sriov_set_totalvfs mention that >> passing numvfs=0 will be interpreted as numvfs=dev->sriov->total_VFs? >> c) is there a better way of indicating "current configuration doesn't >> support VFs" rather than calling set_totalvfs(0)? >> >> Thanks, >> -Edward > > The file shouldn't exist if the device doesn't provide an SRIOV > capability. > If it does, and it's not supported, then add a patch in quirks.c. > > I don't know much about quirks, but I'm not sure they're the answer here, as it's not quite as simple as "driver doesn't support it". It's a firmware / configuration issue, that if the device (it's a NIC) is configured a certain way [1], the VFs - while appearing fine from a PCI perspective - don't actually work (they can't pass traffic). We can't detect this misconfiguration until PF probe time, and we need a way to report that the VFs aren't usable. Can quirks handle this? -Edward [1] SFC9120-based NICs support multiple PFs per port and these can be used as a kind of "poor-man's SR-IOV" (we're calling it 'PF-IOV') by placing the firmware v-switch below the PFs. However, this then precludes adding a v-switch above the PF to direct VF traffic, meaning that VFs are useless in this configuration. Consequently, our configuration tools won't allow VFs and PF-IOV to be enabled simultaneously, but bugs or corruption could cause this to happen. The information contained in this message is confidential and is intended for the addressee(s) only. If you have received this message in error, please notify the sender immediately and delete the message. Unless you are an addressee (or authorized to receive for an addressee), you may not use, copy or disclose to anyone this message or any information contained in this message. The unauthorized use, disclosure, copying or alteration of this message is strictly prohibited. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
