prevent hot unplugging multi function PCI device

We do not support to hot unplug multi function PCI device now. If the device is
one function of multi function PCI device, we shoul not allow to hot unplugg
it.

src/qemu/qemu_hotplug.c

@@ -1157,6 +1157,30 @@ static inline int qemuFindDisk(virDomainDefPtr def, const char *dst)
     return -1;
 }
 
+static int qemuComparePCIDevice(virDomainDefPtr def ATTRIBUTE_UNUSED,
+                                virDomainDeviceInfoPtr dev1,
+                                void *opaque)
+{
+    virDomainDeviceInfoPtr dev2 = opaque;
+
+    if (dev1->type !=  VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI ||
+        dev2->type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI)
+        return 0;
+
+    if (dev1->addr.pci.slot == dev2->addr.pci.slot &&
+        dev1->addr.pci.function != dev2->addr.pci.function)
+        return -1;
+    return 0;
+}
+
+static bool qemuIsMultiFunctionDevice(virDomainDefPtr def,
+                                      virDomainDeviceInfoPtr dev)
+{
+    if (virDomainDeviceInfoIterate(def, qemuComparePCIDevice, dev) < 0)
+        return true;
+    return false;
+}
+
 
 int qemuDomainDetachPciDiskDevice(struct qemud_driver *driver,
                                   virDomainObjPtr vm,
@@ -1178,6 +1202,13 @@ int qemuDomainDetachPciDiskDevice(struct qemud_driver *driver,
 
     detach = vm->def->disks[i];
 
+    if (qemuIsMultiFunctionDevice(vm->def, &detach->info)) {
+        qemuReportError(VIR_ERR_OPERATION_FAILED,
+                        _("cannot hot unplug multifunction PCI device: %s"),
+                        dev->data.disk->dst);
+        goto cleanup;
+    }
+
     if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_DEVICES)) {
         if (virCgroupForDomain(driver->cgroup, vm->def->name, &cgroup, 0) != 0) {
             qemuReportError(VIR_ERR_INTERNAL_ERROR,
@@ -1417,6 +1448,13 @@ int qemuDomainDetachPciControllerDevice(struct qemud_driver *driver,
         goto cleanup;
     }
 
+    if (qemuIsMultiFunctionDevice(vm->def, &detach->info)) {
+        qemuReportError(VIR_ERR_OPERATION_FAILED,
+                        _("cannot hot unplug multifunction PCI device: %s"),
+                        dev->data.disk->dst);
+        goto cleanup;
+    }
+
     if (qemuDomainControllerIsBusy(vm, detach)) {
         qemuReportError(VIR_ERR_OPERATION_FAILED, "%s",
                         _("device cannot be detached: device is busy"));
@@ -1504,6 +1542,13 @@ int qemuDomainDetachNetDevice(struct qemud_driver *driver,
         goto cleanup;
     }
 
+    if (qemuIsMultiFunctionDevice(vm->def, &detach->info)) {
+        qemuReportError(VIR_ERR_OPERATION_FAILED,
+                        _("cannot hot unplug multifunction PCI device :%s"),
+                        dev->data.disk->dst);
+        goto cleanup;
+    }
+
     if ((vlan = qemuDomainNetVLAN(detach)) < 0) {
         qemuReportError(VIR_ERR_OPERATION_FAILED,
                         "%s", _("unable to determine original VLAN"));
@@ -1633,6 +1678,13 @@ int qemuDomainDetachHostPciDevice(struct qemud_driver *driver,
         return -1;
     }
 
+    if (qemuIsMultiFunctionDevice(vm->def, &detach->info)) {
+        qemuReportError(VIR_ERR_OPERATION_FAILED,
+                        _("cannot hot unplug multifunction PCI device: %s"),
+                        dev->data.disk->dst);
+        return -1;
+    }
+
     if (!virDomainDeviceAddressIsValid(&detach->info,
                                        VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI)) {
         qemuReportError(VIR_ERR_OPERATION_FAILED,