virsh: Introduce update-memory-device command

New 'update-memory-device' 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/>? A new
--my-element argument can be easily introduced.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
This commit is contained in:
Michal Privoznik 2021-01-21 17:51:31 +01:00
parent b1c3b5dfec
commit f72e4edf50
2 changed files with 191 additions and 0 deletions

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@ -4919,6 +4919,36 @@ results as some fields may be autogenerated and thus match devices other than
expected.
update-memory-device
--------------------
**Syntax:**
::
update-memory-device domain [--print-xml] [[--alias alias] | [--node node]]
[[--live] [--config] | [--current]]
[--requested-size size]
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* or *--node* 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. The option is valid only for
``virtio-mem`` memory device model.
change-media
------------

View File

@ -8927,6 +8927,161 @@ cmdSetmaxmem(vshControl *ctl, const vshCmd *cmd)
return true;
}
/*
* "update-memory-device" command
*/
static const vshCmdInfo info_update_memory_device[] = {
{.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_device[] = {
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 = "node",
.type = VSH_OT_INT,
.help = N_("memory device target node")
},
{.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;
bool nodeOpt = false;
unsigned int node = 0;
g_autoptr(xmlDoc) doc = NULL;
g_autoptr(xmlXPathContext) ctxt = NULL;
g_autofree char *xpath = NULL;
int nmems;
g_autofree xmlNodePtr *mems = 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;
nodeOpt = vshCommandOptBool(cmd, "node");
if (vshCommandOptStringReq(ctl, cmd, "alias", &alias) < 0 ||
vshCommandOptUInt(ctl, cmd, "node", &node) < 0) {
return -1;
}
if (nodeOpt) {
xpath = g_strdup_printf("/domain/devices/memory[./target/node='%u']", node);
} else 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 or --node 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
cmdUpdateMemoryDevice(vshControl *ctl, const vshCmd *cmd)
{
g_autoptr(virshDomain) dom = NULL;
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);
VSH_EXCLUSIVE_OPTIONS("node", "alias");
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)
return false;
if (vshCommandOptBool(cmd, "print-xml")) {
vshPrint(ctl, "%s", updatedMemoryXML);
} else {
if (virDomainUpdateDeviceFlags(dom, updatedMemoryXML, flags) < 0)
return false;
}
return true;
}
/*
* "memtune" command
*/
@ -14676,6 +14831,12 @@ const vshCmdDef domManagementCmds[] = {
.info = info_update_device,
.flags = 0
},
{.name = "update-memory-device",
.handler = cmdUpdateMemoryDevice,
.opts = opts_update_memory_device,
.info = info_update_memory_device,
.flags = 0
},
{.name = "vcpucount",
.handler = cmdVcpucount,
.opts = opts_vcpucount,