[Qemu-devel] [PATCH 1/2] PCI-e device multi-function hot-add support

[Cao jin]

Enable PCI-e device multifunction hot, just ensure the function 0
added last, then driver will got the notification to scan all the
function in the slot.

Signed-off-by: Cao jin <address@hidden>
---
 hw/pci/pcie.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 6e28985..61ebefd 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -249,16 +249,20 @@ void pcie_cap_slot_hotplug_cb(HotplugHandler 
*hotplug_dev, DeviceState *dev,
         return;
     }
 
-    /* TODO: multifunction hot-plug.
-     * Right now, only a device of function = 0 is allowed to be
-     * hot plugged/unplugged.
+    /* To enable multifunction hot-plug, we just ensure the function
+     * 0 added last. Until function 0 added, we set the sltsta and
+     * inform OS via event notification.
      */
-    assert(PCI_FUNC(pci_dev->devfn) == 0);
-
-    pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
-                               PCI_EXP_SLTSTA_PDS);
-    pcie_cap_slot_event(PCI_DEVICE(hotplug_dev),
-                        PCI_EXP_HP_EV_PDC | PCI_EXP_HP_EV_ABP);
+    if (!(pci_dev->cap_present & QEMU_PCI_CAP_MULTIFUNCTION) &&
+            PCI_FUNC(pci_dev->devfn) > 0) {
+        error_setg(errp, "single function device, function number must be 0,"
+                "but got %d", PCI_FUNC(pci_dev->devfn));
+    } else if (PCI_FUNC(pci_dev->devfn) == 0) {
+        pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
+                                   PCI_EXP_SLTSTA_PDS);
+        pcie_cap_slot_event(PCI_DEVICE(hotplug_dev),
+                            PCI_EXP_HP_EV_PDC | PCI_EXP_HP_EV_ABP);
+    }
 }
 
 void pcie_cap_slot_hot_unplug_request_cb(HotplugHandler *hotplug_dev,
-- 
2.1.0