Re: [libvirt PATCH v3 06/11] 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. Note that some of the the configuration for a mediated device must be passed to mdevctl as a JSON-formatted file. In order to avoid creating and cleaning up temporary files, the JSON is instead fed to stdin and we pass the filename /dev/stdin to mdevctl. While this may not be portable, neither are mediated devices, so I don't believe it should cause any problems. Signed-off-by: Jonathon Jongsma <jjongsma(a)redhat.com&gt; ---

+ char * nodeDeviceGetXMLDesc(virNodeDevicePtr device, @@ -492,6 +518,25 @@ nodeDeviceFindNewDevice(virConnectPtr conn, } +static virNodeDevicePtr +nodeDeviceFindNewMediatedDeviceFunc(virConnectPtr conn, + const void *opaque) +{ + const char *uuid = opaque;

+ return nodeDeviceLookupMediatedDeviceByUUID(conn, uuid, 0); +} + + +static virNodeDevicePtr +nodeDeviceFindNewMediatedDevice(virConnectPtr conn, + const char *mdev_uuid) +{ + return nodeDeviceFindNewDevice(conn, + nodeDeviceFindNewMediatedDeviceFunc, + mdev_uuid); +} + + typedef struct _NewSCSIHostFuncData NewSCSIHostFuncData; struct _NewSCSIHostFuncData { @@ -534,6 +579,158 @@ nodeDeviceHasCapability(virNodeDeviceDefPtr def, virNodeDevCapType type) } +/* format a json string that provides configuration information about this mdev + * to the mdevctl utility */ +static int +nodeDeviceDefToMdevctlConfig(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) + return -1; + + return 0; +} + + +static char * +nodeDeviceFindAddressByName(const char *name) +{ + virNodeDeviceDefPtr def = NULL; + virNodeDevCapsDefPtr caps = NULL; + char *pci_addr = NULL; + virNodeDeviceObjPtr dev = virNodeDeviceObjListFindByName(driver->devs, name); + + if (!dev) { + virReportError(VIR_ERR_NO_NODE_DEVICE, + _("could not find device '%s'"), name); + return NULL; + } + + def = virNodeDeviceObjGetDef(dev); + for (caps = def->caps; caps != NULL; caps = caps->next) { + if (caps->data.type == VIR_NODE_DEV_CAP_PCI_DEV) { + virPCIDeviceAddress addr = { + .domain = caps->data.pci_dev.domain, + .bus = caps->data.pci_dev.bus, + .slot = caps->data.pci_dev.slot, + .function = caps->data.pci_dev.function + }; + + pci_addr = virPCIDeviceAddressAsString(&addr); + break; + } + } + + virNodeDeviceObjEndAPI(&dev); + + return pci_addr; +} + + +virCommandPtr +nodeDeviceGetMdevctlStartCommand(virNodeDeviceDefPtr def, + bool persist, + char **uuid_out) +{ + virCommandPtr cmd; + const char *subcommand; + g_autofree char *json = NULL; + g_autofree char *parent_pci = nodeDeviceFindAddressByName(def->parent); + + if (!parent_pci) { + virReportError(VIR_ERR_NO_NODE_DEVICE, + _("unable to find PCI address for parent device '%s'"), def->parent); + return NULL; + } + + if (nodeDeviceDefToMdevctlConfig(def, &json) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("couldn't convert node device def to mdevctl JSON")); + return NULL; + } + + if (persist) + subcommand = "define";