Since the downstream port is not checked, two slots can be linked to a single port. However, this can prevent the driver from detecting the device properly.
It is necessary to ensure that a downstream port is not linked more than once. Links: https://lore.kernel.org/qemu-devel/oszpr01mb6453bc61d2ff4035f18084ef8d...@oszpr01mb6453.jpnprd01.prod.outlook.com Signed-off-by: Yao Xingtao <yaoxt.f...@fujitsu.com> --- V3[3] -> V4: - make the error message more readable - fix the downstream port check error V2[2] -> V3: - Move this check into pcie_cap_init() V1[1] -> V2: - Move downstream port check forward [1] https://lore.kernel.org/qemu-devel/20240704033834.3362-1-yaoxt.f...@fujitsu.com [2] https://lore.kernel.org/qemu-devel/20240717085621.55315-1-yaoxt.f...@fujitsu.com [3] https://lore.kernel.org/qemu-devel/20240725032731.13032-1-yaoxt.f...@fujitsu.com --- hw/pci/pcie.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c index 4b2f0805c6e0..1e53be1bc7c5 100644 --- a/hw/pci/pcie.c +++ b/hw/pci/pcie.c @@ -192,6 +192,13 @@ int pcie_cap_init(PCIDevice *dev, uint8_t offset, assert(pci_is_express(dev)); + if ((type == PCI_EXP_TYPE_DOWNSTREAM || type == PCI_EXP_TYPE_ROOT_PORT) && + pcie_find_port_by_pn(pci_get_bus(dev), port)) { + error_setg(errp, "The port %d is already in use, please select " + "another port", port); + return -EBUSY; + } + pos = pci_add_capability(dev, PCI_CAP_ID_EXP, offset, PCI_EXP_VER2_SIZEOF, errp); if (pos < 0) { -- 2.41.0
