Re: [libvirt PATCH 5/6] nodedev: add mdev support to virNodeDeviceCreateXML()

With recent additions to the node device xml schema, an xml schema can now describe a mdev device sufficiently for libvirt to create and start the device using the mdevctl utility. Signed-off-by: Jonathon Jongsma <jjongsma(a)redhat.com&gt; ---

} +static int +virNodeDeviceDefToMdevctlConfig(virNodeDeviceDefPtr def, char **buf) +{ + size_t i; + virNodeDevCapMdevPtr mdev = &def->caps->data.mdev; + g_autoptr(virJSONValue) json = virJSONValueNewObject(); + + if (virJSONValueObjectAppendString(json, "mdev_type", mdev->type) < 0) + return -1; + if (virJSONValueObjectAppendString(json, "start", "manual") < 0) + return -1; + if (mdev->attributes) { + g_autoptr(virJSONValue) attributes = virJSONValueNewArray(); + for (i = 0; i < mdev->nattributes; i++) { + virMediatedDeviceAttrPtr attr = mdev->attributes[i]; + g_autoptr(virJSONValue) jsonattr = virJSONValueNewObject(); + + if (virJSONValueObjectAppendString(jsonattr, attr->name, attr->value) < 0) + return -1; + if (virJSONValueArrayAppend(attributes, g_steal_pointer(&jsonattr)) < 0) + return -1; + } + if (virJSONValueObjectAppend(json, "attrs", g_steal_pointer(&attributes)) < 0) + return -1; + } + + *buf = virJSONValueToString(json, false); + if (*buf == NULL)

+ return -1; + + return 0; +} + +static int +virMdevctlStart(const char *parent, const char *json_file, char **uuid) +{ + int status; + g_autofree char *mdevctl = virFindFileInPath(MDEVCTL);

+ if (!mdevctl) + return -1; + + g_autoptr(virCommand) cmd = virCommandNewArgList(mdevctl, + "start", + "-p", + parent, + "--jsonfile", + json_file, + NULL);

+ virCommandAddEnvPassCommon(cmd); + virCommandSetOutputBuffer(cmd, uuid); + + /* an auto-generated uuid is returned via stdout if no uuid is specified in + * the mdevctl args */ + if (virCommandRun(cmd, &status) < 0 || status != 0) + return -1; + + /* remove newline */ + *uuid = g_strstrip(*uuid); + + return 0; +} + virNodeDevicePtr nodeDeviceCreateXML(virConnectPtr conn, const char *xmlDesc, @@ -569,6 +674,78 @@ nodeDeviceCreateXML(virConnectPtr conn, _("no node device for '%s' with matching " "wwnn '%s' and wwpn '%s'"), def->name, wwnn, wwpn); + } else if (nodeDeviceHasCapability(def, VIR_NODE_DEV_CAP_MDEV)) { + virNodeDeviceObjPtr parent_dev = NULL; + virNodeDeviceDefPtr parent_def = NULL; + virNodeDevCapsDefPtr parent_caps = NULL; + g_autofree char *uuid = NULL; + g_autofree char *parent_pci = NULL; + + if (def->parent == NULL) { + virReportError(VIR_ERR_NO_NODE_DEVICE, "%s",

+ _("cannot create a mediated device without a parent")); + return NULL; + } + + if ((parent_dev = virNodeDeviceObjListFindByName(driver->devs, def->parent)) == NULL) { + virReportError(VIR_ERR_NO_NODE_DEVICE, + _("could not find parent device '%s'"), def->parent); + return NULL; + } + + parent_def = virNodeDeviceObjGetDef(parent_dev); + for (parent_caps = parent_def->caps; parent_caps != NULL; parent_caps = parent_caps->next) { + if (parent_caps->data.type == VIR_NODE_DEV_CAP_PCI_DEV) { + virPCIDeviceAddress addr = { + .domain = parent_caps->data.pci_dev.domain, + .bus = parent_caps->data.pci_dev.bus, + .slot = parent_caps->data.pci_dev.slot, + .function = parent_caps->data.pci_dev.function + }; + + parent_pci = virPCIDeviceAddressAsString(&addr); + break; + } + } + + virNodeDeviceObjEndAPI(&parent_dev); + + if (parent_pci == NULL) { + virReportError(VIR_ERR_NO_NODE_DEVICE, + _("unable to find PCI address for parent device '%s'"), def->parent); + return NULL; + } + + /* Convert node device definition to a JSON string formatted for + * mdevctl */ + g_autofree char *json = NULL; + if (virNodeDeviceDefToMdevctlConfig(def, &json) < 0) { + virReportError(VIR_ERR_NO_NODE_DEVICE, "%s",

+ _("couldn't convert node device def to mdevctl JSON")); + return NULL; + } + + g_autofree char *tmp = g_build_filename(driver->stateDir, "mdev-json-XXXXXX", NULL); + gint tmpfd; + + if ((tmpfd = g_mkstemp_full(tmp, O_RDWR | O_CLOEXEC, S_IRUSR | S_IWUSR)) < 0) { + virReportSystemError(errno, "%s", _("Failed to open temp file for write")); + return NULL; + } + if (safewrite(tmpfd, json, strlen(json)) != strlen(json) || + VIR_CLOSE(tmpfd) < 0) { + virReportSystemError(errno, "%s", _("Failed to write temp file")); + return NULL;

+ } + + if (virMdevctlStart(parent_pci, tmp, &uuid) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("Unable to start mediated device")); + return NULL; + } + + if (uuid && uuid[0] != '\0')

+ device = nodeDeviceFindNewMediatedDevice(conn, uuid); } else { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", _("Unsupported device type"));