Show the real cpu shares value in live XML

Currently, the Linux kernel treats values of '0' and '1' as
the minimum of 2. Values larger than the maximum are changed
to the maximum.

Re-reading the shares value after setting it reflects this in
the live domain XML.

src/lxc/lxc_cgroup.c

@@ -38,9 +38,16 @@ static int virLXCCgroupSetupCpuTune(virDomainDefPtr def,
                                     virCgroupPtr cgroup)
 {
     int ret = -1;
-    if (def->cputune.sharesSpecified &&
-        virCgroupSetCpuShares(cgroup, def->cputune.shares) < 0)
-        goto cleanup;
+
+    if (def->cputune.sharesSpecified) {
+        unsigned long long val;
+        if (virCgroupSetCpuShares(cgroup, def->cputune.shares) < 0)
+            goto cleanup;
+
+        if (virCgroupGetCpuShares(cgroup, &val) < 0)
+            goto cleanup;
+        def->cputune.shares = val;
+    }
 
     if (def->cputune.quota != 0 &&
         virCgroupSetCpuCfsQuota(cgroup, def->cputune.quota) < 0)

src/lxc/lxc_driver.c

@@ -1898,10 +1898,14 @@ lxcDomainSetSchedulerParametersFlags(virDomainPtr dom,
 
         if (STREQ(param->field, VIR_DOMAIN_SCHEDULER_CPU_SHARES)) {
             if (flags & VIR_DOMAIN_AFFECT_LIVE) {
+                unsigned long long val;
                 if (virCgroupSetCpuShares(priv->cgroup, params[i].value.ul) < 0)
                     goto cleanup;
 
-                vm->def->cputune.shares = params[i].value.ul;
+                if (virCgroupGetCpuShares(priv->cgroup, &val) < 0)
+                    goto cleanup;
+
+                vm->def->cputune.shares = val;
                 vm->def->cputune.sharesSpecified = true;
             }
 

src/qemu/qemu_cgroup.c

@@ -655,9 +655,15 @@ qemuSetupCpuCgroup(virDomainObjPtr vm)
        }
     }
 
-    if (vm->def->cputune.sharesSpecified &&
-        virCgroupSetCpuShares(priv->cgroup, vm->def->cputune.shares) < 0)
-        return -1;
+    if (vm->def->cputune.sharesSpecified) {
+        unsigned long long val;
+        if (virCgroupSetCpuShares(priv->cgroup, vm->def->cputune.shares) < 0)
+            return -1;
+
+        if (virCgroupGetCpuShares(priv->cgroup, &val) < 0)
+            return -1;
+        vm->def->cputune.shares = val;
+    }
 
     return 0;
 }

src/qemu/qemu_driver.c

@@ -9085,9 +9085,14 @@ qemuDomainSetSchedulerParametersFlags(virDomainPtr dom,
 
         if (STREQ(param->field, VIR_DOMAIN_SCHEDULER_CPU_SHARES)) {
             if (flags & VIR_DOMAIN_AFFECT_LIVE) {
+                unsigned long long val;
                 if (virCgroupSetCpuShares(priv->cgroup, value_ul) < 0)
                     goto cleanup;
-                vm->def->cputune.shares = value_ul;
+
+                if (virCgroupGetCpuShares(priv->cgroup, &val) < 0)
+                    goto cleanup;
+
+                vm->def->cputune.shares = val;
                 vm->def->cputune.sharesSpecified = true;
             }