On Tue, 4 Jul, 2023, 5:39 pm Akihiko Odaki, <akihiko.od...@daynix.com> wrote:
> On 2023/07/04 21:08, Ani Sinha wrote: > > > > > >> On 04-Jul-2023, at 5:32 PM, Akihiko Odaki <akihiko.od...@daynix.com> > wrote: > >> > >> On 2023/07/04 20:59, Ani Sinha wrote: > >>>> On 04-Jul-2023, at 5:24 PM, Akihiko Odaki <akihiko.od...@daynix.com> > wrote: > >>>> > >>>> On 2023/07/04 20:25, Ani Sinha wrote: > >>>>> PCI Express ports only have one slot, so PCI Express devices can > only be > >>>>> plugged into slot 0 on a PCIE port. Add a warning to let users know > when the > >>>>> invalid configuration is used. We may enforce this more strongly > later on once > >>>>> we get more clarity on whether we are introducing a bad regression > for users > >>>>> currenly using the wrong configuration. > >>>>> The change has been tested to not break or alter behaviors of ARI > capable > >>>>> devices by instantiating seven vfs on an emulated igb device (the > maximum > >>>>> number of vfs the linux igb driver supports). The vfs instantiated > correctly > >>>>> and are seen to have non-zero device/slot numbers in the > conventional PCI BDF > >>>>> representation. > >>>>> CC: jus...@redhat.com > >>>>> CC: imamm...@redhat.com > >>>>> CC: m...@redhat.com > >>>>> CC: akihiko.od...@daynix.com > >>>>> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2128929 > >>>>> Signed-off-by: Ani Sinha <anisi...@redhat.com> > >>>>> Reviewed-by: Julia Suvorova <jus...@redhat.com> > >>>>> --- > >>>>> hw/pci/pci.c | 15 +++++++++++++++ > >>>>> 1 file changed, 15 insertions(+) > >>>>> diff --git a/hw/pci/pci.c b/hw/pci/pci.c > >>>>> index e2eb4c3b4a..47517ba3db 100644 > >>>>> --- a/hw/pci/pci.c > >>>>> +++ b/hw/pci/pci.c > >>>>> @@ -65,6 +65,7 @@ bool pci_available = true; > >>>>> static char *pcibus_get_dev_path(DeviceState *dev); > >>>>> static char *pcibus_get_fw_dev_path(DeviceState *dev); > >>>>> static void pcibus_reset(BusState *qbus); > >>>>> +static bool pcie_has_upstream_port(PCIDevice *dev); > >>>>> static Property pci_props[] = { > >>>>> DEFINE_PROP_PCI_DEVFN("addr", PCIDevice, devfn, -1), > >>>>> @@ -2121,6 +2122,20 @@ static void pci_qdev_realize(DeviceState > *qdev, Error **errp) > >>>>> } > >>>>> } > >>>>> + /* > >>>>> + * With SRIOV and ARI, vfs can have non-zero slot in the > conventional > >>>>> + * PCI interpretation as all five bits reserved for slot > addresses are > >>>>> + * also used for function bits for the various vfs. Ignore that > case. > >>>> > >>>> You don't have to mention SR/IOV; it affects all ARI-capable devices. > A PF can also have non-zero slot number in the conventional interpretation > so you shouldn't call it vf either. > >>> Can you please help write a comment that explains this properly for > all cases - ARI/non-ARI, PFs and VFs? Once everyone agrees that its clear > and correct, I will re-spin. > >> > >> Simply, you can say: > >> With ARI, the slot number field in the conventional PCI interpretation > can have a non-zero value as the field bits are reused to extend the > function number bits. Ignore that case. > > > > but we are not checking for ARI capability here in the code. So the > comment is confusing. > > Don't we? We check for: > !pcie_find_capability(pci_dev, PCI_EXT_CAP_ID_ARI) > Yes I was thinking of patch 6 in the series which also adds a comment for ARI. I'll wait to see what others thought of your suggestion before respinning patch 5 > > >> > >>>> > >>>>> + */ > >>>>> + if (pci_is_express(pci_dev) && > >>>>> + !pcie_find_capability(pci_dev, PCI_EXT_CAP_ID_ARI) && > >>>>> + pcie_has_upstream_port(pci_dev) && > >>>>> + PCI_SLOT(pci_dev->devfn)) { > >>>>> + warn_report("PCI: slot %d is not valid for %s," > >>>>> + " parent device only allows plugging into slot > 0.", > >>>>> + PCI_SLOT(pci_dev->devfn), pci_dev->name); > >>>>> + } > >>>>> + > >>>>> if (pci_dev->failover_pair_id) { > >>>>> if (!pci_bus_is_express(pci_get_bus(pci_dev))) { > >>>>> error_setg(errp, "failover primary device must be on " > > > >
