Re: [libvirt] [PATCH 11/14] Remove the network backend if NIC hotplug fails

If we fail to pci_add a NIC, we should remove the network backend and leave things the way we found them. To do that, we pre-allocate a host_net_remove monitor command and issue that if the pci_add fails. If the remove fails, we just log a warning. We can only do this if we have a name for the network backend and we know the vlan number its associated with. * src/qemu_driver.c: host_net_remove the network backend if the pci_add fails --- src/qemu_driver.c | 35 ++++++++++++++++++++++++++++------- 1 files changed, 28 insertions(+), 7 deletions(-) diff --git a/src/qemu_driver.c b/src/qemu_driver.c index cde789e..4cc78f5 100644 --- a/src/qemu_driver.c +++ b/src/qemu_driver.c @@ -4498,7 +4498,7 @@ static int qemudDomainAttachNetDevice(virConnectPtr conn, unsigned int qemuCmdFlags) { virDomainNetDefPtr net = dev->data.net; - char *cmd, *reply; + char *cmd, *reply, *remove_cmd; int i; if (!(qemuCmdFlags & QEMUD_CMD_FLAG_HOST_NET_ADD)) { @@ -4538,9 +4538,19 @@ static int qemudDomainAttachNetDevice(virConnectPtr conn, "host_net_add ", ' ', net->vlan, -1, &cmd) < 0) return -1; + remove_cmd = NULL; + if (net->vlan >= 0 && net->hostnet_name && + virAsprintf(&remove_cmd, "host_net_remove %d %s", + net->vlan, net->hostnet_name) < 0) { + VIR_FREE(cmd); + virReportOOMError(conn); + 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(remove_cmd); VIR_FREE(cmd); return -1; } @@ -4549,25 +4559,36 @@ static int qemudDomainAttachNetDevice(virConnectPtr conn, 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; - } + "pci_add pci_addr=auto ", ' ', net->vlan, &cmd) < 0) + goto try_remove; 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; + goto try_remove; } VIR_FREE(reply); VIR_FREE(cmd); + VIR_FREE(remove_cmd); vm->def->nets[vm->def->nnets++] = net; return 0; + +try_remove: + reply = NULL; + + if (!remove_cmd) + VIR_WARN0(_("Unable to remove network backend\n")); + else if (qemudMonitorCommand(vm, remove_cmd, &reply) < 0) + VIR_WARN(_("Failed to remove network backend with '%s'\n"), remove_cmd); + + VIR_FREE(reply); + VIR_FREE(remove_cmd); + + return -1; }