> On 04-Jul-2023, at 4:55 PM, Ani Sinha <anisi...@redhat.com> 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.
I wil send a v8 with the patch subject line changed to something like
"hw/pci: warn when PCIE devices are plugged into non-zero slot of PCIE port”
which is more appropriate. Meanwhile, I will wait to get more comments/tags on
v7.
>
> 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.
> + */
> + 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 "
> --
> 2.39.1
>
