[libvirt] [PATCHv2] qemu: numatune/domiftune no support in session mode

[Erik Skultety]

Tuning NUMA or network interface parameters require root
privileges to manage cgroups, thus an attempt to set some of these
parameters in session mode on a running domain should be invalid
followed by an error.
As an example might be memory tuning which raises an error in such case.
Following behavior in session mode will be present after applying
this patch:

   tuning   |      SET      |   GET  |
------------|---------------|--------|
numatune    | shut off only | always |
memtune     |     never     | never  |
domiftune   |     never     | always |

Resolves https://bugzilla.redhat.com/show_bug.cgi?id=1126762
---
 src/qemu/qemu_command.c | 14 +++++++++++++-
 src/qemu/qemu_driver.c  | 35 +++++++++++++++++++++++++----------
 2 files changed, 38 insertions(+), 11 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 1ca98fb..5d4838e 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -7442,7 +7442,7 @@ qemuBuildCommandLine(virConnectPtr conn,
     emulator = def->emulator;
 
     if (!cfg->privileged) {
-        /* If we have no cgroups than we can have no tunings that
+        /* If we have no cgroups then we can have no tunings that
          * require them */
 
         if (def->mem.hard_limit || def->mem.soft_limit ||
@@ -7465,6 +7465,18 @@ qemuBuildCommandLine(virConnectPtr conn,
                            _("CPU tuning is not available in session mode"));
             goto error;
         }
+
+        virDomainNetDefPtr *nets = def->nets;
+        size_t nnets = def->nnets;
+        for (i = 0; i < nnets; i++) {
+            if (nets[i]->bandwidth) {
+                if (nets[i]->bandwidth->in || nets[i]->bandwidth->out) {
+                    virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                                   _("Network bandwidth tuning is not available in session mode"));
+                    goto error;
+                }
+            }
+        }
     }
 
     for (i = 0; i < def->ngraphics; ++i) {
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 3c04678..ad02e68 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -8786,6 +8786,13 @@ qemuDomainSetNumaParameters(virDomainPtr dom,
                                         &persistentDef) < 0)
         goto cleanup;
 
+    if (!cfg->privileged &&
+        flags & VIR_DOMAIN_AFFECT_LIVE) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("NUMA tuning is not available in session mode"));
+        goto cleanup;
+    }
+
     if (flags & VIR_DOMAIN_AFFECT_LIVE) {
         if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPUSET)) {
             virReportError(VIR_ERR_OPERATION_INVALID, "%s",
@@ -8870,6 +8877,7 @@ qemuDomainGetNumaParameters(virDomainPtr dom,
     size_t i;
     virDomainObjPtr vm = NULL;
     virDomainDefPtr persistentDef = NULL;
+    virQEMUDriverConfigPtr cfg = NULL;
     char *nodeset = NULL;
     int ret = -1;
     virCapsPtr caps = NULL;
@@ -8888,6 +8896,7 @@ qemuDomainGetNumaParameters(virDomainPtr dom,
         return -1;
 
     priv = vm->privateData;
+    cfg = virQEMUDriverGetConfig(driver);
 
     if (virDomainGetNumaParametersEnsureACL(dom->conn, vm->def) < 0)
         goto cleanup;
@@ -8905,14 +8914,6 @@ qemuDomainGetNumaParameters(virDomainPtr dom,
         goto cleanup;
     }
 
-    if (flags & VIR_DOMAIN_AFFECT_LIVE) {
-        if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_MEMORY)) {
-            virReportError(VIR_ERR_OPERATION_INVALID,
-                           "%s", _("cgroup memory controller is not mounted"));
-            goto cleanup;
-        }
-    }
-
     for (i = 0; i < QEMU_NB_NUMA_PARAM && i < *nparams; i++) {
         virMemoryParameterPtr param = &params[i];
 
@@ -8935,9 +8936,16 @@ qemuDomainGetNumaParameters(virDomainPtr dom,
                 if (!nodeset)
                     goto cleanup;
             } else {
-                if (virCgroupGetCpusetMems(priv->cgroup, &nodeset) < 0)
-                    goto cleanup;
+                if (!virCgroupHasController(priv->cgroup,
+                                            VIR_CGROUP_CONTROLLER_MEMORY) ||
+                    virCgroupGetCpusetMems(priv->cgroup, &nodeset) < 0) {
+                    nodeset = virDomainNumatuneFormatNodeset(vm->def->numatune,
+                                                             NULL, -1);
+                    if (!nodeset)
+                        goto cleanup;
+                }
             }
+
             if (virTypedParameterAssign(param, VIR_DOMAIN_NUMA_NODESET,
                                         VIR_TYPED_PARAM_STRING, nodeset) < 0)
                 goto cleanup;
@@ -8962,6 +8970,7 @@ qemuDomainGetNumaParameters(virDomainPtr dom,
     if (vm)
         virObjectUnlock(vm);
     virObjectUnref(caps);
+    virObjectUnref(cfg);
     return ret;
 }
 
@@ -9889,6 +9898,12 @@ qemuDomainSetInterfaceParameters(virDomainPtr dom,
     if (virDomainSetInterfaceParametersEnsureACL(dom->conn, vm->def, flags) < 0)
         goto cleanup;
 
+    if (!cfg->privileged) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("Network bandwidth tuning is not available in session mode"));
+        goto cleanup;
+    }
+
     if (!(caps = virQEMUDriverGetCapabilities(driver, false)))
         goto cleanup;
 
-- 
1.9.3