Re: [libvirt PATCH v2 08/16] nodedev: handle mdevs that disappear from mdevctl

mdevctl does not currently provide any events when the list of defined devices changes, so we will need to poll mdevctl for the list of defined devices periodically. When a mediated device no longer exists from one iteration to the next, we need to treat it as an "undefine" event. When we get such an event, we remove the device from the list if it's not active. Otherwise, we simply mark it as non-persistent. Signed-off-by: Jonathon Jongsma <jjongsma(a)redhat.com&gt; --- src/node_device/node_device_driver.c | 61 ++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/src/node_device/node_device_driver.c b/src/node_device/node_device_driver.c index 349426757e..affd707a65 100644 --- a/src/node_device/node_device_driver.c +++ b/src/node_device/node_device_driver.c @@ -1089,6 +1089,37 @@ nodeDeviceGenerateName(virNodeDeviceDefPtr def, } } +static bool +mdevMatchPersistentDevices(virConnectPtr conn G_GNUC_UNUSED, + virNodeDeviceDefPtr def) +{ + return (def->caps->data.type == VIR_NODE_DEV_CAP_MDEV && + def->caps->data.mdev.persistent);

+ + +} + +/* returns a null-terminated array of strings. Free with virStringListFree() */ +static char ** +nodeDeviceGetMdevPersistentDevices(virNodeDeviceObjListPtr devlist) +{ + char **ret = NULL; + int ndevs = virNodeDeviceObjListNumOfDevices(devlist, + NULL, + "mdev", + mdevMatchPersistentDevices); + if (VIR_ALLOC_N(ret, ndevs+1) < 0) + return NULL; + + if (virNodeDeviceObjListGetNames(devlist, NULL, + mdevMatchPersistentDevices, + "mdev", + ret, + ndevs) < 0) + VIR_FREE(ret); + + return ret; +}

static int virMdevctlListDefined(virNodeDeviceDefPtr **devs) @@ -1113,6 +1144,7 @@ mdevctlEnumerateDevices(void) g_autofree virNodeDeviceDefPtr *devs = NULL; int ndevs; size_t i; + char **oldmdevs = nodeDeviceGetMdevPersistentDevices(driver->devs); if ((ndevs = virMdevctlListDefined(&devs)) < 0) { virReportSystemError(errno, "%s", @@ -1160,7 +1192,36 @@ mdevctlEnumerateDevices(void) event = virNodeDeviceEventUpdateNew(dev->name); virNodeDeviceObjEndAPI(&obj); virObjectEventStateQueue(driver->nodeDeviceEventState, event); + + virStringListRemove(&oldmdevs, dev->name); + } + + /* Any mdevs that were previously defined but were not returned by mdevctl + * this time will need to be checked to see if they should be removed from + * the device list */ + for (i = 0; i < virStringListLength((const char **)oldmdevs); i++) { + const char *name = oldmdevs[i]; + virNodeDeviceObjPtr obj = NULL; + if ((obj = virNodeDeviceObjListFindByName(driver->devs, name))) { + if (!virNodeDeviceObjIsActive(obj)) { + /* An existing device is not active and is no longer defined by + * mdevctl, so remove it */ + virObjectEventPtr event = virNodeDeviceEventLifecycleNew(name, + VIR_NODE_DEVICE_EVENT_DELETED, + 0); + + virNodeDeviceObjListRemove(driver->devs, obj); + virObjectEventStateQueue(driver->nodeDeviceEventState, event); + } else { + /* An existing device is active, but no longer defined. Keep + * the device in the list, but mark it as non-persistent */ + virNodeDeviceDefPtr def = virNodeDeviceObjGetDef(obj); + def->caps->data.mdev.persistent = false; + } + virNodeDeviceObjEndAPI(&obj);