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

[Cao jin]

In case user regret when hot-add multi-function, we should roll back,
device_del the function added but still not worked.

Signed-off-by: Cao jin <address@hidden>
---
 hw/pci/pcie.c | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 61ebefd..b83a244 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -265,10 +265,33 @@ void pcie_cap_slot_hotplug_cb(HotplugHandler 
*hotplug_dev, DeviceState *dev,
     }
 }
 
+static void pcie_unplug_device(PCIBus *bus, PCIDevice *dev, void *opaque)
+{
+    object_unparent(OBJECT(dev));
+}
+
 void pcie_cap_slot_hot_unplug_request_cb(HotplugHandler *hotplug_dev,
                                          DeviceState *dev, Error **errp)
 {
     uint8_t *exp_cap;
+    PCIDevice *pci_dev = PCI_DEVICE(dev);
+    PCIBus *bus = pci_dev->bus;
+
+    /* handle the condition: user want to hot-add multi function, but regret
+     * before finish it, and want to delete the added but not worked function.
+     */
+    if (PCI_FUNC(pci_dev->devfn) > 0 &&
+        bus->devices[PCI_DEVFN(0,0)] == NULL) {
+        pci_for_each_device(bus, pci_bus_num(bus),
+                            pcie_unplug_device, NULL);
+
+        pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
+                                     PCI_EXP_SLTSTA_PDS);
+        pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
+                                   PCI_EXP_SLTSTA_PDC);
+
+        return;
+    }
 
     pcie_cap_slot_hotplug_common(PCI_DEVICE(hotplug_dev), dev, &exp_cap, errp);
 
@@ -382,11 +405,6 @@ void pcie_cap_slot_reset(PCIDevice *dev)
     hotplug_event_update_event_status(dev);
 }
 
-static void pcie_unplug_device(PCIBus *bus, PCIDevice *dev, void *opaque)
-{
-    object_unparent(OBJECT(dev));
-}
-
 void pcie_cap_slot_write_config(PCIDevice *dev,
                                 uint32_t addr, uint32_t val, int len)
 {
-- 
2.1.0