PCIE root ports and other upstream ports only allow one device on slot 0. When hotplugging a device on a pcie root port, make sure that the device address passed always represents slot 0. Any other slot value would be illegal on a root port.
CC: jus...@redhat.com CC: imamm...@redhat.com Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2128929 Signed-off-by: Ani Sinha <anisi...@redhat.com> --- hw/pci/pci.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) changelog: v2: feedback from mst included. diff --git a/hw/pci/pci.c b/hw/pci/pci.c index bf38905b7d..66999352cc 100644 --- a/hw/pci/pci.c +++ b/hw/pci/pci.c @@ -64,6 +64,7 @@ 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), @@ -1182,6 +1183,11 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, } else if (dev->hotplugged && !pci_is_vf(pci_dev) && pci_get_function_0(pci_dev)) { + /* + * populating function 0 triggers a bus scan from the guest that + * exposes other non-zero functions. Hence we need to ensure that + * function 0 is available. + */ error_setg(errp, "PCI: slot %d function 0 already occupied by %s," " new func %s cannot be exposed to guest.", PCI_SLOT(pci_get_function_0(pci_dev)->devfn), @@ -1189,6 +1195,16 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, name); return NULL; + } else if (dev->hotplugged && + !pci_is_vf(pci_dev) && + pcie_has_upstream_port(pci_dev) && PCI_SLOT(devfn)) { + /* + * If the device is being plugged into an upstream PCIE port, + * like a pcie root port, we only support one device at slot 0 + */ + error_setg(errp, "PCI: slot %d is not valid for %s", + PCI_SLOT(devfn), name); + return NULL; } pci_dev->devfn = devfn; -- 2.39.1
