Re: [libvirt] [PATCH 10/14] Basic qemu NIC hotplug support

Implement basic NIC hotplug support using the 'host_net_add' and 'pci_add' qemu monitor commands. For now, we don't support 'bridge' or 'network' types. Also, if pci_add fails, we currently fail to remove the backend which we added.

diff --git a/src/qemu_driver.c b/src/qemu_driver.c index cbc185c..cde789e 100644 --- a/src/qemu_driver.c +++ b/src/qemu_driver.c @@ -4492,6 +4492,84 @@ static int qemudDomainAttachUsbMassstorageDevice(virConnectPtr conn, return 0; } +static int qemudDomainAttachNetDevice(virConnectPtr conn, + virDomainObjPtr vm, + virDomainDeviceDefPtr dev, + unsigned int qemuCmdFlags) +{ + virDomainNetDefPtr net = dev->data.net; + char *cmd, *reply; + int i; + + if (!(qemuCmdFlags & QEMUD_CMD_FLAG_HOST_NET_ADD)) { + qemudReportError(conn, dom, NULL, VIR_ERR_NO_SUPPORT, _("%s"), + "installed qemu version does not support host_net_add"); + return -1; + } + + if (net->type == VIR_DOMAIN_NET_TYPE_BRIDGE || + net->type == VIR_DOMAIN_NET_TYPE_NETWORK) { + qemudReportError(conn, dom, NULL, VIR_ERR_NO_SUPPORT, + _("network device type '%s' cannot be attached"), + virDomainNetTypeToString(net->type)); + return -1; + } + + if (VIR_REALLOC_N(vm->def->nets, vm->def->nnets+1) < 0) { + virReportOOMError(conn); + return -1; + } + + if ((qemuCmdFlags & QEMUD_CMD_FLAG_NET_NAME) && + qemuAssignNetNames(vm->def, net) < 0) { + virReportOOMError(conn); + return -1; + } + + /* Choose a vlan value greater than all other values since + * older versions did not store the value in the state file. + */ + net->vlan = vm->def->nnets; + for (i = 0; i < vm->def->nnets; i++) + if (vm->def->nets[i]->vlan >= net->vlan) + net->vlan = vm->def->nets[i]->vlan; + + if (qemuBuildHostNetStr(conn, net, + "host_net_add ", ' ', net->vlan, -1, &cmd) < 0) + return -1; + + if (qemudMonitorCommand(vm, cmd, &reply) < 0) { + qemudReportError(conn, dom, NULL, VIR_ERR_OPERATION_FAILED, + _("failed to add network backend with '%s'"), cmd); + VIR_FREE(cmd); + return -1; + } + + VIR_FREE(reply); + VIR_FREE(cmd); + + if (qemuBuildNicStr(conn, net, + "pci_add pci_addr=auto ", ' ', net->vlan, &cmd) < 0) { + /* FIXME: try and remove the backend again */ + return -1; + } + + if (qemudMonitorCommand(vm, cmd, &reply) < 0) { + /* FIXME: try and remove the backend again */ + qemudReportError(conn, dom, NULL, VIR_ERR_OPERATION_FAILED, + _("failed to add NIC with '%s'"), cmd); + VIR_FREE(cmd); + return -1; + } + + VIR_FREE(reply); + VIR_FREE(cmd); + + vm->def->nets[vm->def->nnets++] = net; + + return 0; +}