[PATCH 16/22] target/arm: Extract verify_accel_features() from cpu_realize()

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

When looking at the arm_cpu_realizefn() method, most of the
code run before the cpu_exec_realizefn() call checks whether
the requested CPU features are compatible with the requested
accelerator. Extract this code to a dedicated handler matching
our recently added CPUClass::verify_accel_features() handler.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 target/arm/cpu.c | 41 ++++++++++++++++++++++++-----------------
 1 file changed, 24 insertions(+), 17 deletions(-)

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 46d3f70d63..a551383fd3 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -1675,19 +1675,10 @@ void arm_cpu_finalize_features(ARMCPU *cpu, Error **errp)
     }
 }
 
-static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
+static bool arm_cpu_verify_accel_features(CPUState *cs, Error **errp)
 {
-    CPUState *cs = CPU(dev);
-    ARMCPU *cpu = ARM_CPU(dev);
-    ARMCPUClass *acc = ARM_CPU_GET_CLASS(dev);
+    ARMCPU *cpu = ARM_CPU(cs);
     CPUARMState *env = &cpu->env;
-    int pagebits;
-    Error *local_err = NULL;
-
-    /* Use pc-relative instructions in system-mode */
-#ifndef CONFIG_USER_ONLY
-    cs->tcg_cflags |= CF_PCREL;
-#endif
 
     /* If we needed to query the host kernel for the CPU features
      * then it's possible that might have failed in the initfn, but
@@ -1699,10 +1690,13 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
         } else {
             error_setg(errp, "Failed to retrieve host CPU features");
         }
-        return;
+        return false;
     }
 
 #ifndef CONFIG_USER_ONLY
+    /* Use pc-relative instructions in system-mode */
+    cs->tcg_cflags |= CF_PCREL;
+
     /* The NVIC and M-profile CPU are two halves of a single piece of
      * hardware; trying to use one without the other is a command line
      * error and will result in segfaults if not caught here.
@@ -1710,12 +1704,12 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
     if (arm_feature(env, ARM_FEATURE_M)) {
         if (!env->nvic) {
             error_setg(errp, "This board cannot be used with Cortex-M CPUs");
-            return;
+            return false;
         }
     } else {
         if (env->nvic) {
             error_setg(errp, "This board can only be used with Cortex-M CPUs");
-            return;
+            return false;
         }
     }
 
@@ -1733,23 +1727,35 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
             error_setg(errp,
                        "Cannot enable %s when using an M-profile guest CPU",
                        current_accel_name());
-            return;
+            return false;
         }
         if (cpu->has_el3) {
             error_setg(errp,
                        "Cannot enable %s when guest CPU has EL3 enabled",
                        current_accel_name());
-            return;
+            return false;
         }
         if (cpu->tag_memory) {
             error_setg(errp,
                        "Cannot enable %s when guest CPUs has MTE enabled",
                        current_accel_name());
-            return;
+            return false;
         }
     }
 #endif
 
+    return true;
+}
+
+static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
+{
+    CPUState *cs = CPU(dev);
+    ARMCPU *cpu = ARM_CPU(dev);
+    ARMCPUClass *acc = ARM_CPU_GET_CLASS(dev);
+    CPUARMState *env = &cpu->env;
+    int pagebits;
+    Error *local_err = NULL;
+
     cpu_exec_realizefn(cs, &local_err);
     if (local_err != NULL) {
         error_propagate(errp, local_err);
@@ -2383,6 +2389,7 @@ static void arm_cpu_class_init(ObjectClass *oc, void *data)
                                        &acc->parent_phases);
 
     cc->class_by_name = arm_cpu_class_by_name;
+    cc->verify_accel_features = arm_cpu_verify_accel_features;
     cc->has_work = arm_cpu_has_work;
     cc->dump_state = arm_cpu_dump_state;
     cc->set_pc = arm_cpu_set_pc;
-- 
2.41.0