[Kimchi-devel] [PATCH v2 1/2] Forbid user to edit CPU value if topology is defined

[Jose Ricardo Ziviani]

 - When a cpu topology is defined, the number of cpus must always be the
   product of sockets * cores * threads, otherwise libvirt will complain
   about it.

Signed-off-by: Jose Ricardo Ziviani <joserz at linux.vnet.ibm.com>
---
 src/kimchi/i18n.py      |  1 +
 src/kimchi/model/vms.py | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/src/kimchi/i18n.py b/src/kimchi/i18n.py
index ecc10ff..26621a1 100644
--- a/src/kimchi/i18n.py
+++ b/src/kimchi/i18n.py
@@ -127,6 +127,7 @@ messages = {
     "KCHVM0054E": _("VM '%(vm)s' cannot have more than %(cpus)d CPUs. Please update the CPU value when the VM is not running."),
     "KCHVM0055E": _("VM '%(vm)s' cannot have less than %(cpus)d CPUs. Please update the CPU value when the VM is not running."),
     "KCHVM0056E": _("Unable to hotplug CPUs. Details: %(err)s"),
+    "KCHVM0057E": _("Cannot change VCPU value because '%(vm)s' has a topology defined - sockets: %(sockets)s, cores: %(cores)s, threads: %(threads)s."),
 
     "KCHVMHDEV0001E": _("VM %(vmid)s does not contain directly assigned host device %(dev_name)s."),
     "KCHVMHDEV0002E": _("The host device %(dev_name)s is not allowed to directly assign to VM."),
diff --git a/src/kimchi/model/vms.py b/src/kimchi/model/vms.py
index 3ea8903..871f51e 100644
--- a/src/kimchi/model/vms.py
+++ b/src/kimchi/model/vms.py
@@ -85,6 +85,8 @@ XPATH_DOMAIN_DEV_CPU_ID = '/domain/devices/spapr-cpu-socket/@id'
 
 XPATH_NUMA_CELL = './cpu/numa/cell'
 
+XPATH_TOPOLOGY = './cpu/topology'
+
 # key: VM name; value: lock object
 vm_locks = {}
 
@@ -834,6 +836,28 @@ class VMModel(object):
             cpus = params['cpus']
 
             if DOM_STATE_MAP[dom.info()[0]] == 'shutoff':
+
+                # user cannot change vcpu if topology is defined. In this case
+                # vcpu must always be sockets * cores * threads.
+                xml = dom.XMLDesc(0)
+                sockets = xpath_get_text(xml, XPATH_TOPOLOGY + '/@sockets')
+                cores = xpath_get_text(xml, XPATH_TOPOLOGY + '/@cores')
+                threads = xpath_get_text(xml, XPATH_TOPOLOGY + '/@threads')
+                current_vcpu = dom.vcpusFlags(libvirt.VIR_DOMAIN_VCPU_MAXIMUM)
+
+                if sockets and cores and threads:
+                    if current_vcpu != cpus:
+                        raise InvalidOperation('KCHVM0057E',
+                                               {'vm': dom.name(),
+                                                'sockets': sockets[0],
+                                                'cores': cores[0],
+                                                'threads': threads[0]})
+
+                    # do not need to update vcpu if the value edit did not
+                    # change
+                    else:
+                        return
+
                 try:
                     # set maximum VCPU count
                     max_vcpus = self.conn.get().getMaxVcpus('kvm')
-- 
1.9.1