https://bugzilla.redhat.com/show_bug.cgi?id=1447169 With this patch users can cold plug a watchdog. Things are pretty simple because a domain can have at most one watchdog device. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_driver.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index b7824512c..583908972 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -7842,6 +7842,7 @@ qemuDomainAttachDeviceConfig(virDomainDefPtr vmdef, virDomainFSDefPtr fs; virDomainRedirdevDefPtr redirdev; virDomainShmemDefPtr shmem; + virDomainWatchdogDefPtr watchdog; switch ((virDomainDeviceType) dev->type) { case VIR_DOMAIN_DEVICE_DISK: @@ -7978,10 +7979,20 @@ qemuDomainAttachDeviceConfig(virDomainDefPtr vmdef, dev->data.shmem = NULL; break; + case VIR_DOMAIN_DEVICE_WATCHDOG: + watchdog = dev->data.watchdog; + if (vmdef->watchdog) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("domain already has a watchdog")); + return -1; + } + vmdef->watchdog = watchdog; + dev->data.watchdog = NULL;

+ break; + case VIR_DOMAIN_DEVICE_INPUT: case VIR_DOMAIN_DEVICE_SOUND: case VIR_DOMAIN_DEVICE_VIDEO: - case VIR_DOMAIN_DEVICE_WATCHDOG: case VIR_DOMAIN_DEVICE_GRAPHICS: case VIR_DOMAIN_DEVICE_HUB: case VIR_DOMAIN_DEVICE_SMARTCARD:

https://bugzilla.redhat.com/show_bug.cgi?id=1447169 Once again, since domain can have at most one watchdog it simplifies things a bit. However, since we must be able to set the watchdog action as well, new monitor command needs to be used. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_alias.c | 15 ++++- src/qemu/qemu_alias.h | 2 + src/qemu/qemu_command.c | 2 +- src/qemu/qemu_command.h | 3 + src/qemu/qemu_driver.c | 10 +++- src/qemu/qemu_hotplug.c | 64 ++++++++++++++++++++++ src/qemu/qemu_hotplug.h | 3 + src/qemu/qemu_monitor.c | 12 ++++ src/qemu/qemu_monitor.h | 2 + src/qemu/qemu_monitor_json.c | 28 ++++++++++ src/qemu/qemu_monitor_json.h | 3 + tests/qemuhotplugtest.c | 9 ++- .../qemuhotplug-watchdog.xml | 1 + .../qemuhotplug-base-live+watchdog.xml | 55 +++++++++++++++++++ 14 files changed, 205 insertions(+), 4 deletions(-) create mode 100644 tests/qemuhotplugtestdevices/qemuhotplug-watchdog.xml create mode 100644 tests/qemuhotplugtestdomains/qemuhotplug-base-live+watchdog.xml diff --git a/src/qemu/qemu_alias.c b/src/qemu/qemu_alias.c index 914b2b94d..63f69e80f 100644 --- a/src/qemu/qemu_alias.c +++ b/src/qemu/qemu_alias.c @@ -405,6 +405,19 @@ qemuAssignDeviceShmemAlias(virDomainDefPtr def, } +int +qemuAssignDeviceWatchdogAlias(virDomainWatchdogDefPtr watchdog) +{ + const int idx = 0; + + /* Currently, there's just one watchdog per domain */ + + if (virAsprintf(&watchdog->info.alias, "watchdog%d", idx) < 0)

+ return -1; + return 0; +} + + int qemuAssignDeviceAliases(virDomainDefPtr def, virQEMUCapsPtr qemuCaps) { @@ -482,7 +495,7 @@ qemuAssignDeviceAliases(virDomainDefPtr def, virQEMUCapsPtr qemuCaps) return -1; } if (def->watchdog) { - if (virAsprintf(&def->watchdog->info.alias, "watchdog%d", 0) < 0) + if (qemuAssignDeviceWatchdogAlias(def->watchdog) < 0) return -1; } if (def->memballoon) { diff --git a/src/qemu/qemu_alias.h b/src/qemu/qemu_alias.h index 300fd4de5..652ffea0c 100644 --- a/src/qemu/qemu_alias.h +++ b/src/qemu/qemu_alias.h @@ -65,6 +65,8 @@ int qemuAssignDeviceShmemAlias(virDomainDefPtr def, virDomainShmemDefPtr shmem, int idx); +int qemuAssignDeviceWatchdogAlias(virDomainWatchdogDefPtr watchdog); + int qemuAssignDeviceAliases(virDomainDefPtr def, virQEMUCapsPtr qemuCaps); int qemuDomainDeviceAliasIndex(const virDomainDeviceInfo *info, diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 9a27987d4..eb9df044b 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -3921,7 +3921,7 @@ qemuBuildHostNetStr(virDomainNetDefPtr net, } -static char * +char * qemuBuildWatchdogDevStr(const virDomainDef *def, virDomainWatchdogDefPtr dev, virQEMUCapsPtr qemuCaps) diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h index 6fbfb3e5f..4b504f685 100644 --- a/src/qemu/qemu_command.h +++ b/src/qemu/qemu_command.h @@ -206,5 +206,8 @@ char *qemuBuildShmemDevStr(virDomainDefPtr def, ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3);

+char * qemuBuildWatchdogDevStr(const virDomainDef *def, + virDomainWatchdogDefPtr dev, + virQEMUCapsPtr qemuCaps);

#endif /* __QEMU_COMMAND_H__*/ diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 85b4be360..626148dba 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -7593,12 +7593,20 @@ qemuDomainAttachDeviceLive(virDomainObjPtr vm, } break; + case VIR_DOMAIN_DEVICE_WATCHDOG: + ret = qemuDomainAttachWatchdog(driver, vm, + dev->data.watchdog); + if (!ret) {

+ alias = dev->data.watchdog->info.alias; + dev->data.watchdog = NULL; + } + break; + case VIR_DOMAIN_DEVICE_NONE: case VIR_DOMAIN_DEVICE_FS: case VIR_DOMAIN_DEVICE_INPUT: case VIR_DOMAIN_DEVICE_SOUND: case VIR_DOMAIN_DEVICE_VIDEO: - case VIR_DOMAIN_DEVICE_WATCHDOG: case VIR_DOMAIN_DEVICE_GRAPHICS: case VIR_DOMAIN_DEVICE_HUB: case VIR_DOMAIN_DEVICE_SMARTCARD: diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index b365078ec..989146eb9 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -2866,6 +2866,70 @@ qemuDomainAttachShmemDevice(virQEMUDriverPtr driver, } +int +qemuDomainAttachWatchdog(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainWatchdogDefPtr watchdog) +{ + int ret = -1; + qemuDomainObjPrivatePtr priv = vm->privateData; + virDomainDeviceDef dev = { VIR_DOMAIN_DEVICE_WATCHDOG, { .watchdog = watchdog } }; + virDomainWatchdogAction actualAction = watchdog->action; + char *watchdogstr = NULL; + bool releaseAddress = false; + int rv; + + if (vm->def->watchdog) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("domain already has a watchdog")); + return -1; + } + + if (qemuAssignDeviceWatchdogAlias(watchdog) < 0) + return -1; + + if (!(watchdogstr = qemuBuildWatchdogDevStr(vm->def, watchdog, priv->qemuCaps))) + return -1; + + if (watchdog->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) { + if (qemuDomainEnsurePCIAddress(vm, &dev, driver) < 0) + goto cleanup; + releaseAddress = true; + } + + /* QEMU doesn't have a 'dump' action; we tell qemu to 'pause', then + libvirt listens for the watchdog event, and we perform the dump + ourselves. so convert 'dump' to 'pause' for the qemu cli */ + if (actualAction == VIR_DOMAIN_WATCHDOG_ACTION_DUMP) + actualAction = VIR_DOMAIN_WATCHDOG_ACTION_PAUSE; +

+ qemuDomainObjEnterMonitor(driver, vm); + + rv = qemuMonitorSetWatchdogAction(priv->mon, actualAction);

+ + if (rv >= 0)

+ rv = qemuMonitorAddDevice(priv->mon, watchdogstr); + + if (qemuDomainObjExitMonitor(driver, vm) < 0) { + releaseAddress = false; + goto cleanup; + } + + if (rv < 0) + goto cleanup;

+ + releaseAddress = false; + vm->def->watchdog = watchdog; + ret = 0; + + cleanup: + if (releaseAddress) + qemuDomainReleaseDeviceAddress(vm, &watchdog->info, NULL); + VIR_FREE(watchdogstr); + return ret; +} + + static int qemuDomainChangeNetBridge(virDomainObjPtr vm, virDomainNetDefPtr olddev, diff --git a/src/qemu/qemu_hotplug.h b/src/qemu/qemu_hotplug.h index 985c6733f..a9dfd8f7a 100644 --- a/src/qemu/qemu_hotplug.h +++ b/src/qemu/qemu_hotplug.h @@ -80,6 +80,9 @@ int qemuDomainAttachHostDevice(virConnectPtr conn, int qemuDomainAttachShmemDevice(virQEMUDriverPtr driver, virDomainObjPtr vm, virDomainShmemDefPtr shmem); +int qemuDomainAttachWatchdog(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainWatchdogDefPtr watchdog); int qemuDomainFindGraphicsIndex(virDomainDefPtr def, virDomainGraphicsDefPtr dev); int qemuDomainAttachMemory(virQEMUDriverPtr driver, diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index 19082d8bf..5d3f9df47 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -4343,3 +4343,15 @@ qemuMonitorEventPanicInfoFree(qemuMonitorEventPanicInfoPtr info) VIR_FREE(info); } + + +int +qemuMonitorSetWatchdogAction(qemuMonitorPtr mon, + virDomainWatchdogAction watchdogAction) +{ + VIR_DEBUG("watchdogAction=%d", watchdogAction); + + QEMU_CHECK_MONITOR_JSON(mon); + + return qemuMonitorJSONSetWatchdogAction(mon, watchdogAction); +} diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h index 9805a3390..b8c9409e5 100644 --- a/src/qemu/qemu_monitor.h +++ b/src/qemu/qemu_monitor.h @@ -1132,4 +1132,6 @@ int qemuMonitorSetBlockThreshold(qemuMonitorPtr mon, virJSONValuePtr qemuMonitorQueryNamedBlockNodes(qemuMonitorPtr mon); +int qemuMonitorSetWatchdogAction(qemuMonitorPtr mon, + virDomainWatchdogAction watchdogAction);

#endif /* QEMU_MONITOR_H */ diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index df5fb7c8f..02ba701e6 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -7679,3 +7679,31 @@ qemuMonitorJSONQueryNamedBlockNodes(qemuMonitorPtr mon) return ret; } + + +int +qemuMonitorJSONSetWatchdogAction(qemuMonitorPtr mon, + virDomainWatchdogAction watchdogAction) +{ + virJSONValuePtr cmd; + virJSONValuePtr reply = NULL; + const char *action = virDomainWatchdogActionTypeToString(watchdogAction); + int ret = -1;

+ + if (!(cmd = qemuMonitorJSONMakeCommand("watchdog-set-action", + "s:action", action, + NULL))) + return -1; + if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0) + goto cleanup; + + if (qemuMonitorJSONCheckError(cmd, reply) < 0) + goto cleanup; + + ret = 0; + + cleanup: + virJSONValueFree(cmd); + virJSONValueFree(reply); + return ret; +} diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h index 7462967b5..a7a43d7b8 100644 --- a/src/qemu/qemu_monitor_json.h +++ b/src/qemu/qemu_monitor_json.h @@ -524,4 +524,7 @@ int qemuMonitorJSONSetBlockThreshold(qemuMonitorPtr mon, virJSONValuePtr qemuMonitorJSONQueryNamedBlockNodes(qemuMonitorPtr mon) ATTRIBUTE_NONNULL(1); +int qemuMonitorJSONSetWatchdogAction(qemuMonitorPtr mon, + virDomainWatchdogAction watchdogAction) + ATTRIBUTE_NONNULL(1);

#endif /* QEMU_MONITOR_JSON_H */ diff --git a/tests/qemuhotplugtest.c b/tests/qemuhotplugtest.c index 23a498617..b02ae8034 100644 --- a/tests/qemuhotplugtest.c +++ b/tests/qemuhotplugtest.c @@ -127,6 +127,9 @@ testQemuHotplugAttach(virDomainObjPtr vm, case VIR_DOMAIN_DEVICE_SHMEM: ret = qemuDomainAttachShmemDevice(&driver, vm, dev->data.shmem); break; + case VIR_DOMAIN_DEVICE_WATCHDOG: + ret = qemuDomainAttachWatchdog(&driver, vm, dev->data.watchdog); + break; default: VIR_TEST_VERBOSE("device type '%s' cannot be attached\n", virDomainDeviceTypeToString(dev->type)); @@ -811,10 +814,14 @@ mymain(void) "device_del", QMP_OK, "object-del", QMP_OK); DO_TEST_ATTACH("base-live+disk-scsi-wwn", - "disk-scsi-duplicate-wwn", false, true, + "disk-scsi-duplicate-wwn", false, false,

"human-monitor-command", HMP("OK\\r\\n"), "device_add", QMP_OK); + DO_TEST_ATTACH("base-live", "watchdog", false, false, + "watchdog-set-action", QMP_OK, + "device_add", QMP_OK); + #define DO_TEST_CPU_GROUP(prefix, vcpus, modernhp, expectfail) \ do { \ cpudata.test = prefix; \ diff --git a/tests/qemuhotplugtestdevices/qemuhotplug-watchdog.xml b/tests/qemuhotplugtestdevices/qemuhotplug-watchdog.xml new file mode 100644 index 000000000..7e0e0a863 --- /dev/null +++ b/tests/qemuhotplugtestdevices/qemuhotplug-watchdog.xml @@ -0,0 +1 @@ +<watchdog model='ib700' action='poweroff'/> diff --git a/tests/qemuhotplugtestdomains/qemuhotplug-base-live+watchdog.xml b/tests/qemuhotplugtestdomains/qemuhotplug-base-live+watchdog.xml new file mode 100644 index 000000000..f884eec50 --- /dev/null +++ b/tests/qemuhotplugtestdomains/qemuhotplug-base-live+watchdog.xml @@ -0,0 +1,55 @@ +<domain type='kvm' id='7'> + <name>hotplug</name> + <uuid>d091ea82-29e6-2e34-3005-f02617b36e87</uuid> + <memory unit='KiB'>4194304</memory> + <currentMemory unit='KiB'>4194304</currentMemory> + <vcpu placement='static'>4</vcpu> + <os> + <type arch='x86_64' machine='pc'>hvm</type> + <boot dev='hd'/> + </os> + <features> + <acpi/> + <apic/> + <pae/> + </features> + <clock offset='utc'/> + <on_poweroff>destroy</on_poweroff> + <on_reboot>restart</on_reboot> + <on_crash>restart</on_crash> + <devices> + <emulator>/usr/bin/qemu-system-x86_64</emulator> + <controller type='usb' index='0'> + <alias name='usb'/> + <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/> + </controller> + <controller type='ide' index='0'> + <alias name='ide'/> + <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/> + </controller> + <controller type='scsi' index='0' model='virtio-scsi'> + <alias name='scsi0'/> + <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> + </controller> + <controller type='pci' index='0' model='pci-root'> + <alias name='pci'/> + </controller> + <controller type='virtio-serial' index='0'> + <alias name='virtio-serial0'/> + <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> + </controller> + <input type='mouse' bus='ps2'> + <alias name='input0'/> + </input> + <input type='keyboard' bus='ps2'> + <alias name='input1'/> + </input> + <watchdog model='ib700' action='poweroff'> + <alias name='watchdog0'/> + </watchdog> + <memballoon model='none'> + <alias name='balloon0'/> + </memballoon> + </devices> + <seclabel type='none' model='none'/> +</domain>

Once again, since domain can have at most one watchdog it simplifies things a bit. However, since we must be able to set the watchdog action as well, new monitor command needs to be used. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_alias.c | 15 ++++- src/qemu/qemu_alias.h | 2 + src/qemu/qemu_command.c | 2 +- src/qemu/qemu_command.h | 3 + src/qemu/qemu_driver.c | 10 +++- src/qemu/qemu_hotplug.c | 64 ++++++++++++++++++++++ src/qemu/qemu_hotplug.h | 3 + src/qemu/qemu_monitor.c | 12 ++++ src/qemu/qemu_monitor.h | 2 + src/qemu/qemu_monitor_json.c | 28 ++++++++++ src/qemu/qemu_monitor_json.h | 3 + tests/qemuhotplugtest.c | 9 ++- .../qemuhotplug-watchdog.xml | 1 + .../qemuhotplug-base-live+watchdog.xml | 55 +++++++++++++++++++ 14 files changed, 205 insertions(+), 4 deletions(-) create mode 100644 tests/qemuhotplugtestdevices/qemuhotplug-watchdog.xml create mode 100644 tests/qemuhotplugtestdomains/qemuhotplug-base-live+watchdog.xml diff --git a/src/qemu/qemu_alias.c b/src/qemu/qemu_alias.c index 914b2b94d..63f69e80f 100644 --- a/src/qemu/qemu_alias.c +++ b/src/qemu/qemu_alias.c @@ -405,6 +405,19 @@ qemuAssignDeviceShmemAlias(virDomainDefPtr def, } +int +qemuAssignDeviceWatchdogAlias(virDomainWatchdogDefPtr watchdog) +{ + const int idx = 0; + + /* Currently, there's just one watchdog per domain */ + + if (virAsprintf(&watchdog->info.alias, "watchdog%d", idx) < 0) + return -1; + return 0; +} + + int qemuAssignDeviceAliases(virDomainDefPtr def, virQEMUCapsPtr qemuCaps) { @@ -482,7 +495,7 @@ qemuAssignDeviceAliases(virDomainDefPtr def, virQEMUCapsPtr qemuCaps) return -1; } if (def->watchdog) { - if (virAsprintf(&def->watchdog->info.alias, "watchdog%d", 0) < 0) + if (qemuAssignDeviceWatchdogAlias(def->watchdog) < 0) return -1; } if (def->memballoon) { diff --git a/src/qemu/qemu_alias.h b/src/qemu/qemu_alias.h index 300fd4de5..652ffea0c 100644 --- a/src/qemu/qemu_alias.h +++ b/src/qemu/qemu_alias.h @@ -65,6 +65,8 @@ int qemuAssignDeviceShmemAlias(virDomainDefPtr def, virDomainShmemDefPtr shmem, int idx); +int qemuAssignDeviceWatchdogAlias(virDomainWatchdogDefPtr watchdog); + int qemuAssignDeviceAliases(virDomainDefPtr def, virQEMUCapsPtr qemuCaps); int qemuDomainDeviceAliasIndex(const virDomainDeviceInfo *info, diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 9a27987d4..eb9df044b 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -3921,7 +3921,7 @@ qemuBuildHostNetStr(virDomainNetDefPtr net, } -static char * +char * qemuBuildWatchdogDevStr(const virDomainDef *def, virDomainWatchdogDefPtr dev, virQEMUCapsPtr qemuCaps) diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h index 6fbfb3e5f..4b504f685 100644 --- a/src/qemu/qemu_command.h +++ b/src/qemu/qemu_command.h @@ -206,5 +206,8 @@ char *qemuBuildShmemDevStr(virDomainDefPtr def, ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3); +char * qemuBuildWatchdogDevStr(const virDomainDef *def, + virDomainWatchdogDefPtr dev, + virQEMUCapsPtr qemuCaps); #endif /* __QEMU_COMMAND_H__*/ diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 85b4be360..626148dba 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -7593,12 +7593,20 @@ qemuDomainAttachDeviceLive(virDomainObjPtr vm, } break; + case VIR_DOMAIN_DEVICE_WATCHDOG: + ret = qemuDomainAttachWatchdog(driver, vm, + dev->data.watchdog); + if (!ret) { + alias = dev->data.watchdog->info.alias; + dev->data.watchdog = NULL; + } + break; + case VIR_DOMAIN_DEVICE_NONE: case VIR_DOMAIN_DEVICE_FS: case VIR_DOMAIN_DEVICE_INPUT: case VIR_DOMAIN_DEVICE_SOUND: case VIR_DOMAIN_DEVICE_VIDEO: - case VIR_DOMAIN_DEVICE_WATCHDOG: case VIR_DOMAIN_DEVICE_GRAPHICS: case VIR_DOMAIN_DEVICE_HUB: case VIR_DOMAIN_DEVICE_SMARTCARD: diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index b365078ec..989146eb9 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -2866,6 +2866,70 @@ qemuDomainAttachShmemDevice(virQEMUDriverPtr driver, } +int +qemuDomainAttachWatchdog(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainWatchdogDefPtr watchdog) +{ + int ret = -1; + qemuDomainObjPrivatePtr priv = vm->privateData; + virDomainDeviceDef dev = { VIR_DOMAIN_DEVICE_WATCHDOG, { .watchdog = watchdog } }; + virDomainWatchdogAction actualAction = watchdog->action; + char *watchdogstr = NULL; + bool releaseAddress = false; + int rv; + + if (vm->def->watchdog) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("domain already has a watchdog")); + return -1; + } + + if (qemuAssignDeviceWatchdogAlias(watchdog) < 0) + return -1; + + if (!(watchdogstr = qemuBuildWatchdogDevStr(vm->def, watchdog, priv->qemuCaps))) + return -1; + + if (watchdog->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) { + if (qemuDomainEnsurePCIAddress(vm, &dev, driver) < 0) + goto cleanup; + releaseAddress = true; + } + + /* QEMU doesn't have a 'dump' action; we tell qemu to 'pause', then + libvirt listens for the watchdog event, and we perform the dump + ourselves. so convert 'dump' to 'pause' for the qemu cli */ + if (actualAction == VIR_DOMAIN_WATCHDOG_ACTION_DUMP) + actualAction = VIR_DOMAIN_WATCHDOG_ACTION_PAUSE; + + qemuDomainObjEnterMonitor(driver, vm); + + rv = qemuMonitorSetWatchdogAction(priv->mon, actualAction); + + if (rv >= 0) + rv = qemuMonitorAddDevice(priv->mon, watchdogstr); + + if (qemuDomainObjExitMonitor(driver, vm) < 0) { + releaseAddress = false; + goto cleanup; + } + + if (rv < 0) + goto cleanup; + + releaseAddress = false; + vm->def->watchdog = watchdog; + ret = 0; + + cleanup: + if (releaseAddress) + qemuDomainReleaseDeviceAddress(vm, &watchdog->info, NULL); + VIR_FREE(watchdogstr); + return ret; +} + + static int qemuDomainChangeNetBridge(virDomainObjPtr vm, virDomainNetDefPtr olddev, diff --git a/src/qemu/qemu_hotplug.h b/src/qemu/qemu_hotplug.h index 985c6733f..a9dfd8f7a 100644 --- a/src/qemu/qemu_hotplug.h +++ b/src/qemu/qemu_hotplug.h @@ -80,6 +80,9 @@ int qemuDomainAttachHostDevice(virConnectPtr conn, int qemuDomainAttachShmemDevice(virQEMUDriverPtr driver, virDomainObjPtr vm, virDomainShmemDefPtr shmem); +int qemuDomainAttachWatchdog(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainWatchdogDefPtr watchdog); int qemuDomainFindGraphicsIndex(virDomainDefPtr def, virDomainGraphicsDefPtr dev); int qemuDomainAttachMemory(virQEMUDriverPtr driver, diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index 19082d8bf..5d3f9df47 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -4343,3 +4343,15 @@ qemuMonitorEventPanicInfoFree(qemuMonitorEventPanicInfoPtr info) VIR_FREE(info); } + + +int +qemuMonitorSetWatchdogAction(qemuMonitorPtr mon, + virDomainWatchdogAction watchdogAction) +{ + VIR_DEBUG("watchdogAction=%d", watchdogAction); + + QEMU_CHECK_MONITOR_JSON(mon); + + return qemuMonitorJSONSetWatchdogAction(mon, watchdogAction); +} diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h index 9805a3390..b8c9409e5 100644 --- a/src/qemu/qemu_monitor.h +++ b/src/qemu/qemu_monitor.h @@ -1132,4 +1132,6 @@ int qemuMonitorSetBlockThreshold(qemuMonitorPtr mon, virJSONValuePtr qemuMonitorQueryNamedBlockNodes(qemuMonitorPtr mon); +int qemuMonitorSetWatchdogAction(qemuMonitorPtr mon, + virDomainWatchdogAction watchdogAction); #endif /* QEMU_MONITOR_H */ diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index df5fb7c8f..02ba701e6 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -7679,3 +7679,31 @@ qemuMonitorJSONQueryNamedBlockNodes(qemuMonitorPtr mon) return ret; } + + +int +qemuMonitorJSONSetWatchdogAction(qemuMonitorPtr mon, + virDomainWatchdogAction watchdogAction) +{ + virJSONValuePtr cmd; + virJSONValuePtr reply = NULL; + const char *action = virDomainWatchdogActionTypeToString(watchdogAction); + int ret = -1; + + if (!(cmd = qemuMonitorJSONMakeCommand("watchdog-set-action", + "s:action", action, + NULL))) + return -1; + if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0) + goto cleanup; + + if (qemuMonitorJSONCheckError(cmd, reply) < 0) + goto cleanup; + + ret = 0; + + cleanup: + virJSONValueFree(cmd); + virJSONValueFree(reply); + return ret; +} diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h index 7462967b5..a7a43d7b8 100644 --- a/src/qemu/qemu_monitor_json.h +++ b/src/qemu/qemu_monitor_json.h @@ -524,4 +524,7 @@ int qemuMonitorJSONSetBlockThreshold(qemuMonitorPtr mon, virJSONValuePtr qemuMonitorJSONQueryNamedBlockNodes(qemuMonitorPtr mon) ATTRIBUTE_NONNULL(1); +int qemuMonitorJSONSetWatchdogAction(qemuMonitorPtr mon, + virDomainWatchdogAction watchdogAction) + ATTRIBUTE_NONNULL(1); #endif /* QEMU_MONITOR_JSON_H */ diff --git a/tests/qemuhotplugtest.c b/tests/qemuhotplugtest.c index 23a498617..b02ae8034 100644 --- a/tests/qemuhotplugtest.c +++ b/tests/qemuhotplugtest.c @@ -127,6 +127,9 @@ testQemuHotplugAttach(virDomainObjPtr vm, case VIR_DOMAIN_DEVICE_SHMEM: ret = qemuDomainAttachShmemDevice(&driver, vm, dev->data.shmem); break; + case VIR_DOMAIN_DEVICE_WATCHDOG: + ret = qemuDomainAttachWatchdog(&driver, vm, dev->data.watchdog); + break; default: VIR_TEST_VERBOSE("device type '%s' cannot be attached\n", virDomainDeviceTypeToString(dev->type)); @@ -811,10 +814,14 @@ mymain(void) "device_del", QMP_OK, "object-del", QMP_OK); DO_TEST_ATTACH("base-live+disk-scsi-wwn", - "disk-scsi-duplicate-wwn", false, true, + "disk-scsi-duplicate-wwn", false, false, "human-monitor-command", HMP("OK\\r\\n"), "device_add", QMP_OK); + DO_TEST_ATTACH("base-live", "watchdog", false, false, + "watchdog-set-action", QMP_OK, + "device_add", QMP_OK); + #define DO_TEST_CPU_GROUP(prefix, vcpus, modernhp, expectfail) \ do { \ cpudata.test = prefix; \ diff --git a/tests/qemuhotplugtestdevices/qemuhotplug-watchdog.xml b/tests/qemuhotplugtestdevices/qemuhotplug-watchdog.xml new file mode 100644 index 000000000..7e0e0a863 --- /dev/null +++ b/tests/qemuhotplugtestdevices/qemuhotplug-watchdog.xml @@ -0,0 +1 @@ +<watchdog model='ib700' action='poweroff'/> diff --git a/tests/qemuhotplugtestdomains/qemuhotplug-base-live+watchdog.xml b/tests/qemuhotplugtestdomains/qemuhotplug-base-live+watchdog.xml new file mode 100644 index 000000000..f884eec50 --- /dev/null +++ b/tests/qemuhotplugtestdomains/qemuhotplug-base-live+watchdog.xml @@ -0,0 +1,55 @@ +<domain type='kvm' id='7'> + <name>hotplug</name> + <uuid>d091ea82-29e6-2e34-3005-f02617b36e87</uuid> + <memory unit='KiB'>4194304</memory> + <currentMemory unit='KiB'>4194304</currentMemory> + <vcpu placement='static'>4</vcpu> + <os> + <type arch='x86_64' machine='pc'>hvm</type> + <boot dev='hd'/> + </os> + <features> + <acpi/> + <apic/> + <pae/> + </features> + <clock offset='utc'/> + <on_poweroff>destroy</on_poweroff> + <on_reboot>restart</on_reboot> + <on_crash>restart</on_crash> + <devices> + <emulator>/usr/bin/qemu-system-x86_64</emulator> + <controller type='usb' index='0'> + <alias name='usb'/> + <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/> + </controller> + <controller type='ide' index='0'> + <alias name='ide'/> + <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/> + </controller> + <controller type='scsi' index='0' model='virtio-scsi'> + <alias name='scsi0'/> + <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> + </controller> + <controller type='pci' index='0' model='pci-root'> + <alias name='pci'/> + </controller> + <controller type='virtio-serial' index='0'> + <alias name='virtio-serial0'/> + <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> + </controller> + <input type='mouse' bus='ps2'> + <alias name='input0'/> + </input> + <input type='keyboard' bus='ps2'> + <alias name='input1'/> + </input> + <watchdog model='ib700' action='poweroff'> + <alias name='watchdog0'/> + </watchdog> + <memballoon model='none'> + <alias name='balloon0'/> + </memballoon> + </devices> + <seclabel type='none' model='none'/> +</domain>

On 09/05/2017 07:45 AM, Michal Privoznik wrote: > https://bugzilla.redhat.com/show_bug.cgi?id=1447169 > > Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; > --- > src/qemu/qemu_driver.c | 4 +- > src/qemu/qemu_hotplug.c | 61 ++++++++++++++++++++++ > src/qemu/qemu_hotplug.h | 3 ++ > tests/qemuhotplugtest.c | 7 ++- > .../qemuhotplug-watchdog-full.xml | 3 ++ > 5 files changed, 76 insertions(+), 2 deletions(-) > create mode 100644 tests/qemuhotplugtestdevices/qemuhotplug-watchdog-full.xml > > diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c > index 626148dba..4c636b956 100644 > --- a/src/qemu/qemu_driver.c > +++ b/src/qemu/qemu_driver.c > @@ -7692,12 +7692,14 @@ qemuDomainDetachDeviceLive(virDomainObjPtr vm, > case VIR_DOMAIN_DEVICE_SHMEM: > ret = qemuDomainDetachShmemDevice(driver, vm, dev->data.shmem); > break; > + case VIR_DOMAIN_DEVICE_WATCHDOG: > + ret = qemuDomainDetachWatchdog(driver, vm, dev->data.watchdog); > + break; > > case VIR_DOMAIN_DEVICE_FS: > case VIR_DOMAIN_DEVICE_INPUT: > case VIR_DOMAIN_DEVICE_SOUND: > case VIR_DOMAIN_DEVICE_VIDEO: > - case VIR_DOMAIN_DEVICE_WATCHDOG: > case VIR_DOMAIN_DEVICE_GRAPHICS: > case VIR_DOMAIN_DEVICE_HUB: > case VIR_DOMAIN_DEVICE_SMARTCARD: > diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c > index 989146eb9..44472ce9f 100644 > --- a/src/qemu/qemu_hotplug.c > +++ b/src/qemu/qemu_hotplug.c > @@ -4360,6 +4360,25 @@ qemuDomainRemoveShmemDevice(virQEMUDriverPtr driver, > } > > > +static int > +qemuDomainRemoveWatchdog(virQEMUDriverPtr driver, > + virDomainObjPtr vm, > + virDomainWatchdogDefPtr watchdog) > +{ > + virObjectEventPtr event = NULL; > + > + VIR_DEBUG("Removing watchdog %s from domain %p %s", Is "Removing watchdog watchdog0 from ..." a bit superfluous? Perhaps just "Removing '%s' from ..." > + watchdog->info.alias, vm, vm->def->name); > + This would/could be the place for the virDomainAuditWatchdog for "detach" too. > + event = virDomainEventDeviceRemovedNewFromObj(vm, watchdog->info.alias); > + qemuDomainEventQueue(driver, event); > + qemuDomainReleaseDeviceAddress(vm, &watchdog->info, NULL); > + virDomainWatchdogDefFree(vm->def->watchdog); > + vm->def->watchdog = NULL; > + return 0; > +} > + > + > int > qemuDomainRemoveDevice(virQEMUDriverPtr driver, > virDomainObjPtr vm, > @@ -5076,6 +5095,48 @@ qemuDomainDetachShmemDevice(virQEMUDriverPtr driver, > } > > > +int > +qemuDomainDetachWatchdog(virQEMUDriverPtr driver, > + virDomainObjPtr vm, > + virDomainWatchdogDefPtr dev) > +{ > + int ret = -1; > + virDomainWatchdogDefPtr watchdog; Why not watchdog = vm->def->watchdog; here? > + qemuDomainObjPrivatePtr priv = vm->privateData; > + > + /* While domains can have up to one watchdog, the one supplied by user s/by/by the/ > + * doesn't necessarily match the one domain has. Refuse to detach in such > + * case. */ > + if (!(vm->def->watchdog && > + STREQ_NULLABLE(dev->info.alias, > + vm->def->watchdog->info.alias))) { if (!watchdog || STRNEQ_NULLABLE(dev->info.alias, watchdog->info.alias)) Trying to think why NULLABLE would be necessary... So it seems it's required that that input XML has the alias - something not quite right with that...

I would think for unplug there'd be something that would compare the input "model" and "action" values to whatever watchdog is currently present and if they don't match, then fail. Not sure why comparing the alias is "right". It's not something we require of other unplugs, is it?

We just need to make sure the same "something" is being removed. Since the alias is essentially static for the single available watchdog device, then as long as the model and action are the same, we can remove; otherwise, someone has to fix the input XML to have the matching model and action.

On Tue, Sep 26, 2017 at 11:38:26AM +0200, Michal Privoznik wrote: > On 09/12/2017 04:29 PM, John Ferlan wrote: >> >> >> On 09/05/2017 07:45 AM, Michal Privoznik wrote: >>> https://bugzilla.redhat.com/show_bug.cgi?id=1447169 >>> >>> Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; >>> --- >>> src/qemu/qemu_driver.c | 4 +- >>> src/qemu/qemu_hotplug.c | 61 ++++++++++++++++++++++ >>> src/qemu/qemu_hotplug.h | 3 ++ >>> tests/qemuhotplugtest.c | 7 ++- >>> .../qemuhotplug-watchdog-full.xml | 3 ++ >>> 5 files changed, 76 insertions(+), 2 deletions(-) >>> create mode 100644 tests/qemuhotplugtestdevices/qemuhotplug-watchdog-full.xml >>> >>> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c >>> index 626148dba..4c636b956 100644 >>> --- a/src/qemu/qemu_driver.c >>> +++ b/src/qemu/qemu_driver.c >>> @@ -7692,12 +7692,14 @@ qemuDomainDetachDeviceLive(virDomainObjPtr vm, >>> case VIR_DOMAIN_DEVICE_SHMEM: >>> ret = qemuDomainDetachShmemDevice(driver, vm, dev->data.shmem); >>> break; >>> + case VIR_DOMAIN_DEVICE_WATCHDOG: >>> + ret = qemuDomainDetachWatchdog(driver, vm, dev->data.watchdog); >>> + break; >>> >>> case VIR_DOMAIN_DEVICE_FS: >>> case VIR_DOMAIN_DEVICE_INPUT: >>> case VIR_DOMAIN_DEVICE_SOUND: >>> case VIR_DOMAIN_DEVICE_VIDEO: >>> - case VIR_DOMAIN_DEVICE_WATCHDOG: >>> case VIR_DOMAIN_DEVICE_GRAPHICS: >>> case VIR_DOMAIN_DEVICE_HUB: >>> case VIR_DOMAIN_DEVICE_SMARTCARD: >>> diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c >>> index 989146eb9..44472ce9f 100644 >>> --- a/src/qemu/qemu_hotplug.c >>> +++ b/src/qemu/qemu_hotplug.c >>> @@ -4360,6 +4360,25 @@ qemuDomainRemoveShmemDevice(virQEMUDriverPtr driver, >>> } >>> >>> >>> +static int >>> +qemuDomainRemoveWatchdog(virQEMUDriverPtr driver, >>> + virDomainObjPtr vm, >>> + virDomainWatchdogDefPtr watchdog) >>> +{ >>> + virObjectEventPtr event = NULL; >>> + >>> + VIR_DEBUG("Removing watchdog %s from domain %p %s", >> >> Is "Removing watchdog watchdog0 from ..." a bit superfluous? >> >> Perhaps just "Removing '%s' from ..." >> >>> + watchdog->info.alias, vm, vm->def->name); >>> + >> >> This would/could be the place for the virDomainAuditWatchdog for >> "detach" too. >> >>> + event = virDomainEventDeviceRemovedNewFromObj(vm, watchdog->info.alias); >>> + qemuDomainEventQueue(driver, event); >>> + qemuDomainReleaseDeviceAddress(vm, &watchdog->info, NULL); >>> + virDomainWatchdogDefFree(vm->def->watchdog); >>> + vm->def->watchdog = NULL; >>> + return 0; >>> +} >>> + >>> + >>> int >>> qemuDomainRemoveDevice(virQEMUDriverPtr driver, >>> virDomainObjPtr vm, >>> @@ -5076,6 +5095,48 @@ qemuDomainDetachShmemDevice(virQEMUDriverPtr driver, >>> } >>> >>> >>> +int >>> +qemuDomainDetachWatchdog(virQEMUDriverPtr driver, >>> + virDomainObjPtr vm, >>> + virDomainWatchdogDefPtr dev) >>> +{ >>> + int ret = -1; >>> + virDomainWatchdogDefPtr watchdog; >> >> Why not watchdog = vm->def->watchdog; here? >> >>> + qemuDomainObjPrivatePtr priv = vm->privateData; >>> + >>> + /* While domains can have up to one watchdog, the one supplied by user >> >> s/by/by the/ >> >>> + * doesn't necessarily match the one domain has. Refuse to detach in such >>> + * case. */ >>> + if (!(vm->def->watchdog && >>> + STREQ_NULLABLE(dev->info.alias, >>> + vm->def->watchdog->info.alias))) { >> >> if (!watchdog || STRNEQ_NULLABLE(dev->info.alias, watchdog->info.alias)) >> >> Trying to think why NULLABLE would be necessary... So it seems it's >> required that that input XML has the alias - something not quite right >> with that... > > Is that so? We match devices based on their alias in a lot of places. > Users are expected to pass the full device XML anyway. So it's up to us > how we pick the right device to be detached. For instance, when > detaching a vNIC we match MAC addresses and ignore the rest, since MAC > identifies the device uniquely. So for instance, if the detach XML > provided by user has <bandwidth/> set but the one in domain doesn't have > it, we detach the device anyway. One can argue this is a buggy > behaviour. But I just don't think we should care. There's a line we have > to draw between protecting users from themselves and too complex and > mostly useless code. So we've documented that users are supposed to pass > the device XML as is in the domain XML. We can protect ourselves from the danger of user passing incomplete device XML by not using the passed in device XML directly. IOW, once we parse the XML to create our virDomainDevicePtr instance, lets say we want the dev->disk virDomainDiskDefPtr to unplug a disk. Don't use the the dev->disk pointer in the unplug code. Instead use the dev->disk to lookup the def->disk[N] we want from virDomaniDefPtr and then use that virDomainDiskDefPtr instead. That way our code doesn't have to be paranoid about incompletely specified device configs. This is safer because we'll inevitably forget to be paranoid enough in places which leaves us vulnerable to crashes / bugs.

On 09/26/2017 05:38 AM, Michal Privoznik wrote: > On 09/12/2017 04:29 PM, John Ferlan wrote: >> >> >> On 09/05/2017 07:45 AM, Michal Privoznik wrote: >>> https://bugzilla.redhat.com/show_bug.cgi?id=1447169 >>> >>> Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; >>> --- >>> src/qemu/qemu_driver.c | 4 +- >>> src/qemu/qemu_hotplug.c | 61 ++++++++++++++++++++++ >>> src/qemu/qemu_hotplug.h | 3 ++ >>> tests/qemuhotplugtest.c | 7 ++- >>> .../qemuhotplug-watchdog-full.xml | 3 ++ >>> 5 files changed, 76 insertions(+), 2 deletions(-) >>> create mode 100644 tests/qemuhotplugtestdevices/qemuhotplug-watchdog-full.xml >>> >>> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c >>> index 626148dba..4c636b956 100644 >>> --- a/src/qemu/qemu_driver.c >>> +++ b/src/qemu/qemu_driver.c >>> @@ -7692,12 +7692,14 @@ qemuDomainDetachDeviceLive(virDomainObjPtr vm, >>> case VIR_DOMAIN_DEVICE_SHMEM: >>> ret = qemuDomainDetachShmemDevice(driver, vm, dev->data.shmem); >>> break; >>> + case VIR_DOMAIN_DEVICE_WATCHDOG: >>> + ret = qemuDomainDetachWatchdog(driver, vm, dev->data.watchdog); >>> + break; >>> >>> case VIR_DOMAIN_DEVICE_FS: >>> case VIR_DOMAIN_DEVICE_INPUT: >>> case VIR_DOMAIN_DEVICE_SOUND: >>> case VIR_DOMAIN_DEVICE_VIDEO: >>> - case VIR_DOMAIN_DEVICE_WATCHDOG: >>> case VIR_DOMAIN_DEVICE_GRAPHICS: >>> case VIR_DOMAIN_DEVICE_HUB: >>> case VIR_DOMAIN_DEVICE_SMARTCARD: >>> diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c >>> index 989146eb9..44472ce9f 100644 >>> --- a/src/qemu/qemu_hotplug.c >>> +++ b/src/qemu/qemu_hotplug.c >>> @@ -4360,6 +4360,25 @@ qemuDomainRemoveShmemDevice(virQEMUDriverPtr driver, >>> } >>> >>> >>> +static int >>> +qemuDomainRemoveWatchdog(virQEMUDriverPtr driver, >>> + virDomainObjPtr vm, >>> + virDomainWatchdogDefPtr watchdog) >>> +{ >>> + virObjectEventPtr event = NULL; >>> + >>> + VIR_DEBUG("Removing watchdog %s from domain %p %s", >> >> Is "Removing watchdog watchdog0 from ..." a bit superfluous? >> >> Perhaps just "Removing '%s' from ..." >> >>> + watchdog->info.alias, vm, vm->def->name); >>> + >> >> This would/could be the place for the virDomainAuditWatchdog for >> "detach" too. >> >>> + event = virDomainEventDeviceRemovedNewFromObj(vm, watchdog->info.alias); >>> + qemuDomainEventQueue(driver, event); >>> + qemuDomainReleaseDeviceAddress(vm, &watchdog->info, NULL); >>> + virDomainWatchdogDefFree(vm->def->watchdog); >>> + vm->def->watchdog = NULL; >>> + return 0; >>> +} >>> + >>> + >>> int >>> qemuDomainRemoveDevice(virQEMUDriverPtr driver, >>> virDomainObjPtr vm, >>> @@ -5076,6 +5095,48 @@ qemuDomainDetachShmemDevice(virQEMUDriverPtr driver, >>> } >>> >>> >>> +int >>> +qemuDomainDetachWatchdog(virQEMUDriverPtr driver, >>> + virDomainObjPtr vm, >>> + virDomainWatchdogDefPtr dev) >>> +{ >>> + int ret = -1; >>> + virDomainWatchdogDefPtr watchdog; >> >> Why not watchdog = vm->def->watchdog; here? >> >>> + qemuDomainObjPrivatePtr priv = vm->privateData; >>> + >>> + /* While domains can have up to one watchdog, the one supplied by user >> >> s/by/by the/ >> >>> + * doesn't necessarily match the one domain has. Refuse to detach in such >>> + * case. */ >>> + if (!(vm->def->watchdog && >>> + STREQ_NULLABLE(dev->info.alias, >>> + vm->def->watchdog->info.alias))) { >> >> if (!watchdog || STRNEQ_NULLABLE(dev->info.alias, watchdog->info.alias)) >> >> Trying to think why NULLABLE would be necessary... So it seems it's >> required that that input XML has the alias - something not quite right >> with that... > > Is that so? We match devices based on their alias in a lot of places. > Users are expected to pass the full device XML anyway. So it's up to us > how we pick the right device to be detached. For instance, when > detaching a vNIC we match MAC addresses and ignore the rest, since MAC > identifies the device uniquely. So for instance, if the detach XML > provided by user has <bandwidth/> set but the one in domain doesn't have > it, we detach the device anyway. One can argue this is a buggy > behaviour. But I just don't think we should care. There's a line we have > to draw between protecting users from themselves and too complex and > mostly useless code. So we've documented that users are supposed to pass > the device XML as is in the domain XML. > Can the alias be user supplied and not be overwritten on attach? IOW: If someone supplies watchdog5 on hot plug, would supplying the same XML work on hot unplug?

Typically I pass/use the same XML for my disk/hostdev hot plug/unplug. Some of those aliases could be tricky unless of course someone's looked at the process arguments.

And of course I now see the NULLABLE is being used because even the input XML doesn't require it, you're checking that it is provided and using that as the sole determination of matching the input XML against what's been loaded into QEMU either via cold or hot plug.

>> >> I would think for unplug there'd be something that would compare the >> input "model" and "action" values to whatever watchdog is currently >> present and if they don't match, then fail. Not sure why comparing the >> alias is "right". It's not something we require of other unplugs, is it? > > Sort of. For instance when detaching disks we only care about the > target. And for a lot of other devices we require alias too. > But we also seem to make use of whatever alias exists for the device in many places... I looked at a few and I couldn't find a case where the alias was required on input for the detach.