Current SR/IOV implementations assume that hardcoded Function numbers
are always available and will not conflict. It is somewhat non-trivial
to make the Function numbers to use controllable to avoid Function
number conflicts so ensure there is only one PF to make the assumption
hold true.
Also warn when non-SR/IOV multifunction was attempted with ARI enabled;
ARI has the next Function number field register, and currently it's
hardcoded to 0, which prevents non-SR/IOV multifunction. It is
certainly possible to add a logic to determine the correct next Function
number according to the configuration, but it's not worth since all
ARI-capable devices are also SR/IOV devices, which do not support
multiple PFs as stated above.
Signed-off-by: Akihiko Odaki <akihiko.od...@daynix.com>
---
hw/pci/pci.c | 59 +++++++++++++++++++++++++++++++++++++---------------
1 file changed, 42 insertions(+), 17 deletions(-)
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 784c02a182..50359a0f3a 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -2124,23 +2124,48 @@ 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_is_express(pci_dev)) {
+ /*
+ * 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 (!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);
+ }
+
+ /*
+ * Current SR/IOV implementations assume that hardcoded Function
numbers
+ * are always available. Ensure there is only one PF to make the
+ * assumption hold true.
+ */
+ if (pcie_find_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV) &&
+ PCI_FUNC(pci_dev->devfn)) {
+ warn_report("PCI: function %d is not valid for %s,"
+ " currently PF can only be assigned to function 0.",
+ PCI_FUNC(pci_dev->devfn), pci_dev->name);
+ }
+
+ /*
+ * ARI has the next Function number field register, and currently it's
+ * hardcoded to 0, which prevents non-SR/IOV multifunction.
+ */
+ if (pcie_find_capability(pci_dev, PCI_EXT_CAP_ID_ARI) &&
+ !pci_is_vf(pci_dev) && (pci_dev->devfn & 0xff)) {
+ warn_report("PCI: function %d is not valid for %s,"
+ " non-SR/IOV multifunction is not supported with ARI
enabled.",
+ pci_dev->devfn & 0xff, pci_dev->name);
+ }
}
if (pci_dev->failover_pair_id) {
--
2.41.0
