[Qemu-devel] [RFC 17/20] target-i386: parse cpu_model string into set of stringified properties

[Igor Mammedov <imammedo@redhat.com>]

cpu_model string does represent features in following format:
 ([+-]feat)|(feat=foo)|(feat)
which makes it impossible directly use property infrastructure
to set features on CPU.
This patch introduces parser that splits CPU name from cpu_model and
converts legacy features string into canonized set of strings that
is compatible with property manipulation infrastructure.

PS:
  * later it could be used as a hook to convert legacy command line
    features to global properties. Then marked as deprecated and
    removed with -cpu option in the future.
  * compiler complains that it's unused function but I guess it is
    easier for review this way

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
 target-i386/cpu.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 6f1b66e..7555b08 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -1111,6 +1111,58 @@ static void cpudef_2_x86_cpu(X86CPU *cpu, x86_def_t *def, Error **errp)
     env->cpuid_xlevel2 = def->xlevel2;
 }
 
+/* convert legacy cpumodel string to string cpu_name and
+ * a uniforms set of custom features that will be applied to CPU
+ * using object_property_parse()
+ */
+static void compat_normalize_cpu_model(const char *cpu_model, char **cpu_name,
+                                        QDict **features, Error **errp)
+{
+
+    char *s = g_strdup(cpu_model);
+    char *featurestr, *sptr;
+
+    *cpu_name = strtok_r(s, ",", &sptr);
+    *features = qdict_new();
+
+    featurestr = strtok_r(NULL, ",", &sptr);
+    while (featurestr) {
+        char *val;
+        if (featurestr[0] == '+') {
+            /*
+             * preseve legacy behaviour, if feature was disabled once
+             * do not allow to enable it again
+             */
+            if (!qdict_haskey(*features, featurestr + 1)) {
+                qdict_put(*features, featurestr + 1, qstring_from_str("on"));
+            }
+        } else if (featurestr[0] == '-') {
+            qdict_put(*features, featurestr + 1, qstring_from_str("off"));
+        } else {
+            val = strchr(featurestr, '=');
+            if (val) {
+                *val = 0; val++;
+                if (!strcmp(featurestr, "vendor")) {
+                    qdict_put(*features, "vendor-override",
+                              qstring_from_str("on"));
+                    qdict_put(*features, featurestr, qstring_from_str(val));
+                } else if (!strcmp(featurestr, "tsc_freq")) {
+                    qdict_put(*features, "tsc-frequency",
+                              qstring_from_str(val));
+                } else {
+                    qdict_put(*features, featurestr, qstring_from_str(val));
+                }
+            } else {
+                qdict_put(*features, featurestr, qstring_from_str("on"));
+            }
+        }
+
+        featurestr = strtok_r(NULL, ",", &sptr);
+    }
+
+    return;
+}
+
 static int cpu_x86_find_by_name(X86CPU *cpu, x86_def_t *x86_cpu_def,
                                 const char *cpu_model, Error **errp)
 {
-- 
1.7.11.2