ppc: move '-cpu foo,compat=xxx' parsing into ppc_cpu_parse_featurestr()

there is a dedicated callback CPUClass::parse_features
which purpose is to convert -cpu features into a set of
global properties AND deal with compat/legacy features
that couldn't be directly translated into CPU's properties.

Create ppc variant of it (ppc_cpu_parse_featurestr) and
move 'compat=val' handling from spapr_cpu_core.c into it.
That removes a dependency of board/core code on cpu_model
parsing and would let to reuse common -cpu parsing
introduced by 6063d4c0

Set "max-cpu-compat" property only if it exists, in practice
it should limit 'compat' hack to spapr machine and allow
to avoid including machine/spapr headers in target/ppc/cpu.c

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

2 files changed, 58 insertions, 0 deletions

diff --git a/target/ppc/cpu-qom.h b/target/ppc/cpu-qom.h
index d0cf6ca2a9..429b47f959 100644
--- a/target/ppc/cpu-qom.h
+++ b/target/ppc/cpu-qom.h
@@ -181,6 +181,7 @@ typedef struct PowerPCCPUClass {
     DeviceRealize parent_realize;
     DeviceUnrealize parent_unrealize;
     void (*parent_reset)(CPUState *cpu);
+    void (*parent_parse_features)(const char *type, char *str, Error **errp);
 
     uint32_t pvr;
     bool (*pvr_match)(struct PowerPCCPUClass *pcc, uint32_t pvr);
diff --git a/target/ppc/translate_init.c b/target/ppc/translate_init.c
index 0d6379fcc5..3d16481ca1 100644
--- a/target/ppc/translate_init.c
+++ b/target/ppc/translate_init.c
@@ -10097,6 +10097,61 @@ static ObjectClass *ppc_cpu_class_by_name(const char *name)
     return NULL;
 }
 
+static void ppc_cpu_parse_featurestr(const char *type, char *features,
+                                     Error **errp)
+{
+    Object *machine = qdev_get_machine();
+    const PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(object_class_by_name(type));
+
+    if (!features) {
+        return;
+    }
+
+    if (object_property_find(machine, "max-cpu-compat", NULL)) {
+        int i;
+        char **inpieces;
+        char *s = features;
+        Error *local_err = NULL;
+        char *compat_str = NULL;
+
+        /*
+         * Backwards compatibility hack:
+         *
+         *   CPUs had a "compat=" property which didn't make sense for
+         *   anything except pseries.  It was replaced by "max-cpu-compat"
+         *   machine option.  This supports old command lines like
+         *       -cpu POWER8,compat=power7
+         *   By stripping the compat option and applying it to the machine
+         *   before passing it on to the cpu level parser.
+         */
+        inpieces = g_strsplit(features, ",", 0);
+        *s = '\0';
+        for (i = 0; inpieces[i]; i++) {
+            if (g_str_has_prefix(inpieces[i], "compat=")) {
+                compat_str = inpieces[i];
+                continue;
+            }
+            if ((i != 0) && (s != features)) {
+                s = g_stpcpy(s, ",");
+            }
+            s = g_stpcpy(s, inpieces[i]);
+        }
+
+        if (compat_str) {
+            char *v = compat_str + strlen("compat=");
+            object_property_set_str(machine, v, "max-cpu-compat", &local_err);
+        }
+        g_strfreev(inpieces);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            return;
+        }
+    }
+
+    /* do property processing with generic handler */
+    pcc->parent_parse_features(type, features, errp);
+}
+
 const char *ppc_cpu_lookup_alias(const char *alias)
 {
     int ai;
@@ -10489,6 +10544,8 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data)
     cc->reset = ppc_cpu_reset;
 
     cc->class_by_name = ppc_cpu_class_by_name;
+    pcc->parent_parse_features = cc->parse_features;
+    cc->parse_features = ppc_cpu_parse_featurestr;
     cc->has_work = ppc_cpu_has_work;
     cc->do_interrupt = ppc_cpu_do_interrupt;
     cc->cpu_exec_interrupt = ppc_cpu_exec_interrupt;