From: Ani Sinha Date: Wed, 5 Jul 2023 11:59:23 +0000 (+0530) Subject: hw/pci: warn when PCIe device is plugged into non-zero slot of downstream port X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=ca92eb5defcf9d1c2106341744a73a03cf26e824;p=qmiga%2Fqemu.git hw/pci: warn when PCIe device is plugged into non-zero slot of downstream port PCIe downstream ports only have a single device 0, 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 once we get more clarity on whether we are introducing a bad regression for users currently 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 igb device supports). The vfs are instantiated correctly and are seen to have non-zero device/slot numbers in the conventional PCI BDF representation. CC: jusual@redhat.com CC: imammedo@redhat.com CC: mst@redhat.com CC: akihiko.odaki@daynix.com Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2128929 Signed-off-by: Ani Sinha Reviewed-by: Julia Suvorova Message-Id: <20230705115925.5339-6-anisinha@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Akihiko Odaki --- diff --git a/hw/pci/pci.c b/hw/pci/pci.c index fb17138f7d..4b14f31859 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 +2122,25 @@ static void pci_qdev_realize(DeviceState *qdev, Error **errp) } } + /* + * A PCIe Downstream Port that do not have ARI Forwarding enabled must + * associate only Device 0 with the device attached to the bus + * representing the Link from the Port (PCIe base spec rev 4.0 ver 0.3, + * sec 7.3.1). + * With ARI, PCI_SLOT() can return non-zero value as the traditional + * 5-bit Device Number and 3-bit Function Number fields in its associated + * Routing IDs, Requester IDs and Completer IDs are interpreted as a + * single 8-bit Function Number. Hence, ignore ARI capable devices. + */ + 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 "