[Qemu-devel] [PATCH 07/12] pci: add a pci_function_is_valid callback to check function if valid

[Zhou Jie]

From: Chen Fan <address@hidden>

PCI hotplug requires that function 0 is added last to close the
slot.  Since vfio supporting AER, we require that the VM bus
contains the same set of devices as the host bus to support AER,
we can perform an AER validation test whenever a function 0 in
the VM is hot-added.

Signed-off-by: Chen Fan <address@hidden>
---
 hw/pci/pci.c         | 32 ++++++++++++++++++++++++++++++++
 include/hw/pci/pci.h |  1 +
 2 files changed, 33 insertions(+)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index bb605ef..acd48eb 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1841,6 +1841,22 @@ PCIDevice *pci_find_device(PCIBus *bus, int bus_num, 
uint8_t devfn)
     return bus->devices[devfn];
 }
 
+static void pci_function_is_valid(PCIBus *bus, PCIDevice *d, void *opaque)
+{
+    PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(d);
+    Error **errp = opaque;
+
+    if (*errp) {
+        return;
+    }
+
+    if (!pc->is_valid_func) {
+        return;
+    }
+
+    pc->is_valid_func(d, errp);
+}
+
 static void pci_qdev_realize(DeviceState *qdev, Error **errp)
 {
     PCIDevice *pci_dev = (PCIDevice *)qdev;
@@ -1883,6 +1899,22 @@ static void pci_qdev_realize(DeviceState *qdev, Error 
**errp)
         pci_qdev_unrealize(DEVICE(pci_dev), NULL);
         return;
     }
+
+    /*
+     *  If the function number is 0, indicate the closure of the slot.
+     *  then we get the chance to check all functions on same device
+     *  if valid.
+     */
+    if (DEVICE(pci_dev)->hotplugged &&
+        pci_get_function_0(pci_dev) == pci_dev) {
+        pci_for_each_device(bus, pci_bus_num(bus),
+                            pci_function_is_valid, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            pci_qdev_unrealize(DEVICE(pci_dev), NULL);
+            return;
+        }
+    }
 }
 
 static void pci_default_realize(PCIDevice *dev, Error **errp)
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index ef6ba51..848fa7b 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -197,6 +197,7 @@ typedef struct PCIDeviceClass {
 
     void (*realize)(PCIDevice *dev, Error **errp);
     int (*init)(PCIDevice *dev);/* TODO convert to realize() and remove */
+    void (*is_valid_func)(PCIDevice *dev, Error **errp);
     PCIUnregisterFunc *exit;
     PCIConfigReadFunc *config_read;
     PCIConfigWriteFunc *config_write;
-- 
1.8.3.1