vcpu_feature:Add support for AMD CPU feature naming variants

Some AMD CPUs (e.g., EPYC 7542) display the cr8legacy feature as "cr8_legacy".
This commit extends the grep pattern matching to accommodate both naming
conventions, ensuring proper feature detection across different CPU models.

Signed-off-by: Liang Cong <lcong@redhat.com>

Author: liang-cong-red-hat

libvirt/tests/cfg/cpu/vcpu_feature.cfg

@@ -19,7 +19,7 @@
                     func_supported_since_libvirt_ver = (10, 7, 0)
                     host_supported_feature = "yes"
                     feature_name = "pauth"
-                    feature_check_name = "paca"
+                    feature_check_pattern = "paca"
                     check_vm_feature = "yes" 
                     check_qemu_pattern = "-cpu host,pauth=off" 
                     cpu_check = "none"
@@ -37,5 +37,6 @@
                     only policy_require
                     host_supported_feature = "no"
                     feature_name = "cr8legacy"
+                    feature_check_pattern = "'cr8legacy\|cr8_legacy'"
                     err_msg = "guest CPU doesn't match specification: missing features: .*${feature_name}"
 

libvirt/tests/src/cpu/vcpu_feature.py

@@ -49,7 +49,7 @@ def update_cpu_xml():
     cpu_mode = params.get('cpu_mode', "host-passthrough")
     cpu_check = params.get('cpu_check', "full")
     feature_name = params.get('feature_name', "vmx")
-    feature_check_name = params.get('feature_check_name', feature_name)
+    feature_check_pattern = params.get('feature_check_pattern', feature_name)
     feature_policy = params.get('feature_policy', "require")
     host_supported_feature = "yes" == params.get("host_supported_feature", "no")
     check_vm_feature = "yes" == params.get("check_vm_feature", "no")
@@ -61,7 +61,7 @@ def update_cpu_xml():
     try:
         libvirt_version.is_libvirt_feature_supported(params)
 
-        flags_cmd = "grep -qw %s /proc/cpuinfo" % feature_check_name
+        flags_cmd = "grep -qw %s /proc/cpuinfo" % feature_check_pattern
         res = process.run(flags_cmd, shell=True, ignore_status=True).exit_status
         if host_supported_feature == bool(res):
             test.cancel('The host does not support current test!')