Re: [PATCH 09/10] virsh: Introduce update-memory command

New 'update-memory' command is introduced which aims on making it user friendly to change <memory/> device. So far I just need to change <requested/> so I'm introducing --requested-size only; but the idea is that this is extensible for other cases too. For instance, want to change <myElement/>? Nnew --my-element argument can be easily introduced.

Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- docs/manpages/virsh.rst | 31 ++++++++ tools/virsh-domain.c | 154 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 185 insertions(+) diff --git a/docs/manpages/virsh.rst b/docs/manpages/virsh.rst index e3afa48f7b..32639e34ff 100644 --- a/docs/manpages/virsh.rst +++ b/docs/manpages/virsh.rst @@ -4891,6 +4891,37 @@ results as some fields may be autogenerated and thus match devices other than expected. +update-memory +------------- + +**Syntax:** + +:: + + update-memory domain [--print-xml] [--alias alias] + [[--live] [--config] | [--current]] + [--requested-size size] + +Update values for a ``<memory/>`` device. Not to be confused with overall +domain memory which is tuned via ``setmem`` and ``setmaxmem``. +This command finds ``<memory/>`` device inside given *domain*, changes +requested values and passes updated device XML to daemon. If *--print-xml* is +specified then the device is not changed, but the updated device XML is printed +to stdout. If there are more than one ``<memory/>`` devices in *domain* use +*--alias* to select the desired one. + +If *--live* is specified, affect a running domain. +If *--config* is specified, affect the next startup of a persistent guest. +If *--current* is specified, it is equivalent to either *--live* or +*--config*, depending on the current state of the guest. +Both *--live* and *--config* flags may be given, but *--current* is +exclusive. Not specifying any flag is the same as specifying *--current*. + +If *--requested-size* is specified then ``<requested/>`` under memory target is +changed to requested *size* (as scaled integer, see ``NOTES`` above). It +defaults to kibibytes if no suffix is provided. + + change-media ------------ diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index 9746117bdb..0b32e6f408 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -9128,6 +9128,154 @@ cmdSetmaxmem(vshControl *ctl, const vshCmd *cmd) return ret; } + +/* + * "update-memory" command + */ +static const vshCmdInfo info_update_memory[] = { + {.name = "help", + .data = N_("update memory device of a domain") + }, + {.name = "desc", + .data = N_("Update values of a memory device of a domain") + }, + {.name = NULL} +}; + +static const vshCmdOptDef opts_update_memory[] = { + VIRSH_COMMON_OPT_DOMAIN_FULL(0), + VIRSH_COMMON_OPT_DOMAIN_CONFIG, + VIRSH_COMMON_OPT_DOMAIN_LIVE, + VIRSH_COMMON_OPT_DOMAIN_CURRENT, + {.name = "print-xml", + .type = VSH_OT_BOOL, + .help = N_("print updated memory device XML instead of executing the change") + }, + {.name = "alias", + .type = VSH_OT_STRING, + .completer = virshDomainDeviceAliasCompleter, + .help = N_("memory device alias"), + }, + {.name = "requested-size", + .type = VSH_OT_INT, + .help = N_("new value of <requested/> size, as scaled integer (default KiB)") + }, + {.name = NULL} +}; + +static int +virshGetUpdatedMemoryXML(char **updatedMemoryXML, + vshControl *ctl, + const vshCmd *cmd, + virDomainPtr dom, + unsigned int flags) +{ + const char *alias = NULL; + g_autoptr(xmlDoc) doc = NULL; + g_autoptr(xmlXPathContext) ctxt = NULL; + g_autofree char *xpath = NULL; + int nmems; + g_autofree xmlNodePtr *mems = NULL; + g_autoptr(xmlBuffer) xmlbuf = NULL; + unsigned int domainXMLFlags = 0; + + if (flags & VIR_DOMAIN_AFFECT_CONFIG) + domainXMLFlags |= VIR_DOMAIN_XML_INACTIVE; + + if (virshDomainGetXMLFromDom(ctl, dom, domainXMLFlags, &doc, &ctxt) < 0) + return -1; + + if (vshCommandOptStringReq(ctl, cmd, "alias", &alias) < 0) + return -1; + + if (alias) { + xpath = g_strdup_printf("/domain/devices/memory[./alias/@name='%s']", alias); + } else { + xpath = g_strdup("/domain/devices/memory"); + } + + nmems = virXPathNodeSet(xpath, ctxt, &mems); + if (nmems < 0) { + vshSaveLibvirtError(); + return -1; + } else if (nmems == 0) { + vshError(ctl, _("no memory device found")); + return -1; + } else if (nmems > 1) { + vshError(ctl, _("multiple memory devices found, use --alias to select one")); + return -1; + } + + ctxt->node = mems[0]; + + if (vshCommandOptBool(cmd, "requested-size")) { + xmlNodePtr requestedSizeNode; + g_autofree char *kibibytesStr = NULL; + unsigned long long bytes = 0; + unsigned long kibibytes = 0; + + if (vshCommandOptScaledInt(ctl, cmd, "requested-size", &bytes, 1024, ULLONG_MAX) < 0) + return -1; + kibibytes = VIR_DIV_UP(bytes, 1024); + + requestedSizeNode = virXPathNode("./target/requested", ctxt); + + if (!requestedSizeNode) { + vshError(ctl, _("virtio-mem device is missing <requested/>")); + return -1; + } + + kibibytesStr = g_strdup_printf("%lu", kibibytes); + xmlNodeSetContent(requestedSizeNode, BAD_CAST kibibytesStr); + } + + if (!(*updatedMemoryXML = virXMLNodeToString(doc, mems[0]))) { + vshSaveLibvirtError(); + return -1; + } + + return 0; +} + +static bool +cmdUpdateMemory(vshControl *ctl, const vshCmd *cmd) +{ + virDomainPtr dom; + bool ret = false; + bool config = vshCommandOptBool(cmd, "config"); + bool live = vshCommandOptBool(cmd, "live"); + bool current = vshCommandOptBool(cmd, "current"); + g_autofree char *updatedMemoryXML = NULL; + unsigned int flags = VIR_DOMAIN_AFFECT_CURRENT; + + VSH_EXCLUSIVE_OPTIONS_VAR(current, live); + VSH_EXCLUSIVE_OPTIONS_VAR(current, config); + + if (config) + flags |= VIR_DOMAIN_AFFECT_CONFIG; + if (live) + flags |= VIR_DOMAIN_AFFECT_LIVE; + + if (!(dom = virshCommandOptDomain(ctl, cmd, NULL))) + return false; + + if (virshGetUpdatedMemoryXML(&updatedMemoryXML, ctl, cmd, dom, flags) < 0) + goto cleanup; + + if (vshCommandOptBool(cmd, "print-xml")) { + vshPrint(ctl, "%s", updatedMemoryXML); + } else { + if (virDomainUpdateDeviceFlags(dom, updatedMemoryXML, flags) < 0) + goto cleanup; + } + + ret = true; + cleanup: + virshDomainFree(dom); + return ret; +} + + /* * "memtune" command */ @@ -14995,6 +15143,12 @@ const vshCmdDef domManagementCmds[] = { .info = info_update_device, .flags = 0 }, + {.name = "update-memory", + .handler = cmdUpdateMemory, + .opts = opts_update_memory, + .info = info_update_memory, + .flags = 0 + }, {.name = "vcpucount", .handler = cmdVcpucount, .opts = opts_vcpucount,