vcpu: add virsh support

* tools/virsh.c (cmdSetvcpus): Add new flags.  Let invalid
commands through to driver, to ease testing of hypervisor argument
validation.
(cmdMaxvcpus, cmdVcpucount): New commands.
(commands): Add new commands.
* tools/virsh.pod (setvcpus, vcpucount, maxvcpus): Document new
behavior.

tools/virsh.c

@@ -2280,11 +2280,217 @@ cmdFreecell(vshControl *ctl, const vshCmd *cmd)
     return TRUE;
 }
 
+/*
+ * "maxvcpus" command
+ */
+static const vshCmdInfo info_maxvcpus[] = {
+    {"help", N_("connection vcpu maximum")},
+    {"desc", N_("Show maximum number of virtual CPUs for guests on this connection.")},
+    {NULL, NULL}
+};
+
+static const vshCmdOptDef opts_maxvcpus[] = {
+    {"type", VSH_OT_STRING, 0, N_("domain type")},
+    {NULL, 0, 0, NULL}
+};
+
+static int
+cmdMaxvcpus(vshControl *ctl, const vshCmd *cmd)
+{
+    char *type;
+    int vcpus;
+
+    type = vshCommandOptString(cmd, "type", NULL);
+
+    if (!vshConnectionUsability(ctl, ctl->conn))
+        return FALSE;
+
+    vcpus = virConnectGetMaxVcpus(ctl->conn, type);
+    if (vcpus < 0)
+        return FALSE;
+    vshPrint(ctl, "%d\n", vcpus);
+
+    return TRUE;
+}
+
+/*
+ * "vcpucount" command
+ */
+static const vshCmdInfo info_vcpucount[] = {
+    {"help", N_("domain vcpu counts")},
+    {"desc", N_("Returns the number of virtual CPUs used by the domain.")},
+    {NULL, NULL}
+};
+
+static const vshCmdOptDef opts_vcpucount[] = {
+    {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")},
+    {"maximum", VSH_OT_BOOL, 0, N_("get maximum cap on vcpus")},
+    {"current", VSH_OT_BOOL, 0, N_("get current vcpu usage")},
+    {"config", VSH_OT_BOOL, 0, N_("get value to be used on next boot")},
+    {"live", VSH_OT_BOOL, 0, N_("get value from running domain")},
+    {NULL, 0, 0, NULL}
+};
+
+static int
+cmdVcpucount(vshControl *ctl, const vshCmd *cmd)
+{
+    virDomainPtr dom;
+    int ret = TRUE;
+    int maximum = vshCommandOptBool(cmd, "maximum");
+    int current = vshCommandOptBool(cmd, "current");
+    int config = vshCommandOptBool(cmd, "config");
+    int live = vshCommandOptBool(cmd, "live");
+    bool all = maximum + current + config + live == 0;
+    int count;
+
+    if (maximum && current) {
+        vshError(ctl, "%s",
+                 _("--maximum and --current cannot both be specified"));
+        return FALSE;
+    }
+    if (config && live) {
+        vshError(ctl, "%s",
+                 _("--config and --live cannot both be specified"));
+        return FALSE;
+    }
+    /* We want one of each pair of mutually exclusive options; that
+     * is, use of flags requires exactly two options.  */
+    if (maximum + current + config + live == 1) {
+        vshError(ctl,
+                 _("when using --%s, either --%s or --%s must be specified"),
+                 (maximum ? "maximum" : current ? "current"
+                  : config ? "config" : "live"),
+                 maximum + current ? "config" : "maximum",
+                 maximum + current ? "live" : "current");
+        return FALSE;
+    }
+
+    if (!vshConnectionUsability(ctl, ctl->conn))
+        return FALSE;
+
+    if (!(dom = vshCommandOptDomain(ctl, cmd, NULL)))
+        return FALSE;
+
+    /* In all cases, try the new API first; if it fails because we are
+     * talking to an older client, try a fallback API before giving
+     * up.  */
+    if (all || (maximum && config)) {
+        count = virDomainGetVcpusFlags(dom, (VIR_DOMAIN_VCPU_MAXIMUM |
+                                             VIR_DOMAIN_VCPU_CONFIG));
+        if (count < 0 && (last_error->code == VIR_ERR_NO_SUPPORT
+                          || last_error->code == VIR_ERR_INVALID_ARG)) {
+            char *tmp;
+            char *xml = virDomainGetXMLDesc(dom, VIR_DOMAIN_XML_INACTIVE);
+            if (xml && (tmp = strstr(xml, "<vcpu"))) {
+                tmp = strchr(tmp, '>');
+                if (!tmp || virStrToLong_i(tmp + 1, &tmp, 10, &count) < 0)
+                    count = -1;
+            }
+            VIR_FREE(xml);
+        }
+
+        if (count < 0) {
+            virshReportError(ctl);
+            ret = FALSE;
+        } else if (all) {
+            vshPrint(ctl, "%-12s %-12s %3d\n", _("maximum"), _("config"),
+                     count);
+        } else {
+            vshPrint(ctl, "%d\n", count);
+        }
+        virFreeError(last_error);
+        last_error = NULL;
+    }
+
+    if (all || (maximum && live)) {
+        count = virDomainGetVcpusFlags(dom, (VIR_DOMAIN_VCPU_MAXIMUM |
+                                             VIR_DOMAIN_VCPU_LIVE));
+        if (count < 0 && (last_error->code == VIR_ERR_NO_SUPPORT
+                          || last_error->code == VIR_ERR_INVALID_ARG)) {
+            count = virDomainGetMaxVcpus(dom);
+        }
+
+        if (count < 0) {
+            virshReportError(ctl);
+            ret = FALSE;
+        } else if (all) {
+            vshPrint(ctl, "%-12s %-12s %3d\n", _("maximum"), _("live"),
+                     count);
+        } else {
+            vshPrint(ctl, "%d\n", count);
+        }
+        virFreeError(last_error);
+        last_error = NULL;
+    }
+
+    if (all || (current && config)) {
+        count = virDomainGetVcpusFlags(dom, VIR_DOMAIN_VCPU_CONFIG);
+        if (count < 0 && (last_error->code == VIR_ERR_NO_SUPPORT
+                          || last_error->code == VIR_ERR_INVALID_ARG)) {
+            char *tmp, *end;
+            char *xml = virDomainGetXMLDesc(dom, VIR_DOMAIN_XML_INACTIVE);
+            if (xml && (tmp = strstr(xml, "<vcpu"))) {
+                end = strchr(tmp, '>');
+                if (end) {
+                    *end = '\0';
+                    tmp = strstr(tmp, "current=");
+                    if (!tmp)
+                        tmp = end + 1;
+                    else {
+                        tmp += strlen("current=");
+                        tmp += *tmp == '\'' || *tmp == '"';
+                    }
+                }
+                if (!tmp || virStrToLong_i(tmp, &tmp, 10, &count) < 0)
+                    count = -1;
+            }
+            VIR_FREE(xml);
+        }
+
+        if (count < 0) {
+            virshReportError(ctl);
+            ret = FALSE;
+        } else if (all) {
+            vshPrint(ctl, "%-12s %-12s %3d\n", _("current"), _("config"),
+                     count);
+        } else {
+            vshPrint(ctl, "%d\n", count);
+        }
+        virFreeError(last_error);
+        last_error = NULL;
+    }
+
+    if (all || (current && live)) {
+        count = virDomainGetVcpusFlags(dom, VIR_DOMAIN_VCPU_LIVE);
+        if (count < 0 && (last_error->code == VIR_ERR_NO_SUPPORT
+                          || last_error->code == VIR_ERR_INVALID_ARG)) {
+            virDomainInfo info;
+            if (virDomainGetInfo(dom, &info) == 0)
+                count = info.nrVirtCpu;
+        }
+
+        if (count < 0) {
+            virshReportError(ctl);
+            ret = FALSE;
+        } else if (all) {
+            vshPrint(ctl, "%-12s %-12s %3d\n", _("current"), _("live"),
+                     count);
+        } else {
+            vshPrint(ctl, "%d\n", count);
+        }
+        virFreeError(last_error);
+        last_error = NULL;
+    }
+
+    virDomainFree(dom);
+    return ret;
+}
+
 /*
  * "vcpuinfo" command
  */
 static const vshCmdInfo info_vcpuinfo[] = {
-    {"help", N_("domain vcpu information")},
+    {"help", N_("detailed domain vcpu information")},
     {"desc", N_("Returns basic information about the domain virtual CPUs.")},
     {NULL, NULL}
 };
@@ -2514,6 +2720,9 @@ static const vshCmdInfo info_setvcpus[] = {
 static const vshCmdOptDef opts_setvcpus[] = {
     {"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")},
     {"count", VSH_OT_DATA, VSH_OFLAG_REQ, N_("number of virtual CPUs")},
+    {"maximum", VSH_OT_BOOL, 0, N_("set maximum limit on next boot")},
+    {"config", VSH_OT_BOOL, 0, N_("affect next boot")},
+    {"live", VSH_OT_BOOL, 0, N_("affect running domain")},
     {NULL, 0, 0, NULL}
 };
 
@@ -2522,8 +2731,13 @@ cmdSetvcpus(vshControl *ctl, const vshCmd *cmd)
 {
     virDomainPtr dom;
     int count;
-    int maxcpu;
     int ret = TRUE;
+    int maximum = vshCommandOptBool(cmd, "maximum");
+    int config = vshCommandOptBool(cmd, "config");
+    int live = vshCommandOptBool(cmd, "live");
+    int flags = ((maximum ? VIR_DOMAIN_VCPU_MAXIMUM : 0) |
+                 (config ? VIR_DOMAIN_VCPU_CONFIG : 0) |
+                 (live ? VIR_DOMAIN_VCPU_LIVE : 0));
 
     if (!vshConnectionUsability(ctl, ctl->conn))
         return FALSE;
@@ -2532,26 +2746,15 @@ cmdSetvcpus(vshControl *ctl, const vshCmd *cmd)
         return FALSE;
 
     count = vshCommandOptInt(cmd, "count", &count);
-    if (count <= 0) {
-        vshError(ctl, "%s", _("Invalid number of virtual CPUs."));
-        virDomainFree(dom);
-        return FALSE;
-    }
-
-    maxcpu = virDomainGetMaxVcpus(dom);
-    if (maxcpu <= 0) {
-        virDomainFree(dom);
-        return FALSE;
-    }
-
-    if (count > maxcpu) {
-        vshError(ctl, "%s", _("Too many virtual CPUs."));
-        virDomainFree(dom);
-        return FALSE;
-    }
 
-    if (virDomainSetVcpus(dom, count) != 0) {
-        ret = FALSE;
+    if (!flags) {
+        if (virDomainSetVcpus(dom, count) != 0) {
+            ret = FALSE;
+        }
+    } else {
+        if (virDomainSetVcpusFlags(dom, count, flags) < 0) {
+            ret = FALSE;
+        }
     }
 
     virDomainFree(dom);
@@ -9642,6 +9845,7 @@ static const vshCmdDef commands[] = {
     {"freecell", cmdFreecell, opts_freecell, info_freecell},
     {"hostname", cmdHostname, NULL, info_hostname},
     {"list", cmdList, opts_list, info_list},
+    {"maxvcpus", cmdMaxvcpus, opts_maxvcpus, info_maxvcpus},
     {"migrate", cmdMigrate, opts_migrate, info_migrate},
     {"migrate-setmaxdowntime", cmdMigrateSetMaxDowntime, opts_migrate_setmaxdowntime, info_migrate_setmaxdowntime},
 
@@ -9748,6 +9952,7 @@ static const vshCmdDef commands[] = {
     {"vol-name", cmdVolName, opts_vol_name, info_vol_name},
     {"vol-key", cmdVolKey, opts_vol_key, info_vol_key},
 
+    {"vcpucount", cmdVcpucount, opts_vcpucount, info_vcpucount},
     {"vcpuinfo", cmdVcpuinfo, opts_vcpuinfo, info_vcpuinfo},
     {"vcpupin", cmdVcpupin, opts_vcpupin, info_vcpupin},
     {"version", cmdVersion, NULL, info_version},

tools/virsh.pod

@@ -443,7 +443,14 @@ Remove the managed save file for a domain if it exists.  The next time the
 domain is started it will not restore to its previous state but instead will
 do a full boot.
 
-=item B<migrate> optional I<--live> I<--suspend> I<domain-id> I<desturi> I<migrateuri>
+=item B<maxvcpus> optional I<type>
+
+Provide the maximum number of virtual CPUs supported for a guest VM on
+this connection.  If provided, the I<type> parameter must be a valid
+type attribute for the <domain> element of XML.
+
+=item B<migrate> optional I<--live> I<--suspend> I<domain-id> I<desturi>
+I<migrateuri>
 
 Migrate domain to another host.  Add --live for live migration; --suspend
 leaves the domain paused on the destination host. The I<desturi> is the
@@ -521,7 +528,8 @@ Displays the domain memory parameters.
 
 Allows you to set the domain memory parameters. LXC and QEMU/KVM supports these parameters.
 
-=item B<setvcpus> I<domain-id> I<count>
+=item B<setvcpus> I<domain-id> I<count> optional I<--maximum> I<--config>
+I<--live>
 
 Change the number of virtual CPUs active in the guest domain. Note that
 I<count> may be limited by host, hypervisor or limit coming from the
@@ -530,6 +538,17 @@ original description of domain.
 For Xen, you can only adjust the virtual CPUs of a running domain if
 the domain is paravirtualized.
 
+If I<--config> is specified, the change will only affect the next
+boot of a domain.  If I<--live> is specified, the domain must be
+running, and the change takes place immediately.  Both flags may be
+specified, if supported by the hypervisor.  If neither flag is given,
+then I<--live> is implied and it is up to the hypervisor whether
+I<--config> is also implied.
+
+If I<--maximum> is specified, then you must use I<--config> and
+avoid I<--live>; this flag controls the maximum limit of vcpus that
+can be hot-plugged the next time the domain is booted.
+
 =item B<shutdown> I<domain-id>
 
 Gracefully shuts down a domain.  This coordinates with the domain OS
@@ -568,6 +587,21 @@ is not available the processes will provide an exit code of 1.
 Undefine the configuration for an inactive domain. Since it's not running
 the domain name or UUID must be used as the I<domain-id>.
 
+=item B<vcpucount> I<domain-id>  optional I<--maximum> I<--current>
+I<--config> I<--live>
+
+Print information about the virtual cpu counts of the given
+I<domain-id>.  If no flags are specified, all possible counts are
+listed in a table; otherwise, the output is limited to just the
+numeric value requested.
+
+I<--maximum> requests information on the maximum cap of vcpus that a
+domain can add via B<setvcpus>, while I<--current> shows the current
+usage; these two flags cannot both be specified.  I<--config>
+requests information regarding the next time the domain will be
+booted, while I<--live> requires a running domain and lists current
+values; these two flags cannot both be specified.
+
 =item B<vcpuinfo> I<domain-id>
 
 Returns basic information about the domain virtual CPUs, like the number of