Add RHEV host detection support (#17177)

* Add RHEV host detection support

This adds RHEV host detection support based on a running 'vdsm' process and the existence of _/rhev/_ (which are both part of the vdsm RPM package in a RHEV installation). Without this change, a RHEV host would be reported as a kvm host (which is also true, but often not specific enough).

This closes #17058

* Only scan the process list when we determined /rhev/ exists

Small performance improvement, so we do not have to scan the process list if /rhev/ does not exist.

lib/ansible/module_utils/facts.py

@@ -3353,7 +3353,22 @@ class LinuxVirtual(Virtual):
                 modules.append(data[0])
 
             if 'kvm' in modules:
-                self.facts['virtualization_type'] = 'kvm'
+
+                if os.path.isdir('/rhev/'):
+
+                    # Check whether this is a RHEV hypervisor (is vdsm running ?)
+                    for f in glob.glob('/proc/[0-9]*/comm'):
+                        try:
+                            if open(f).read().rstrip() == 'vdsm':
+                                self.facts['virtualization_type'] = 'RHEV'
+                                break
+                        except:
+                            pass
+                    else:
+                        self.facts['virtualization_type'] = 'kvm'
+
+                else:
+                    self.facts['virtualization_type'] = 'kvm'
                 self.facts['virtualization_role'] = 'host'
                 return