accel-cpu: make cpu_realizefn return a bool

overall, all devices' realize functions take an Error **errp, but return void.

hw/core/qdev.c code, which realizes devices, therefore does:

local_err = NULL;
dc->realize(dev, &local_err);
if (local_err != NULL) {
    goto fail;
}

However, we can improve at least accel_cpu to return a meaningful bool value.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210322132800.7470-9-cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

accel/accel-common.c

@@ -98,14 +98,14 @@ void accel_cpu_instance_init(CPUState *cpu)
     }
 }
 
-void accel_cpu_realizefn(CPUState *cpu, Error **errp)
+bool accel_cpu_realizefn(CPUState *cpu, Error **errp)
 {
     CPUClass *cc = CPU_GET_CLASS(cpu);
 
     if (cc->accel_cpu && cc->accel_cpu->cpu_realizefn) {
-        /* NB: errp parameter is unused currently */
-        cc->accel_cpu->cpu_realizefn(cpu, errp);
+        return cc->accel_cpu->cpu_realizefn(cpu, errp);
     }
+    return true;
 }
 
 static const TypeInfo accel_cpu_type = {

cpu.c

@@ -130,8 +130,9 @@ void cpu_exec_realizefn(CPUState *cpu, Error **errp)
     CPUClass *cc = CPU_GET_CLASS(cpu);
 
     cpu_list_add(cpu);
-    accel_cpu_realizefn(cpu, errp);
-
+    if (!accel_cpu_realizefn(cpu, errp)) {
+        return;
+    }
 #ifdef CONFIG_TCG
     /* NB: errp parameter is unused currently */
     if (tcg_enabled()) {

include/hw/core/accel-cpu.h

@@ -32,7 +32,7 @@ typedef struct AccelCPUClass {
 
     void (*cpu_class_init)(CPUClass *cc);
     void (*cpu_instance_init)(CPUState *cpu);
-    void (*cpu_realizefn)(CPUState *cpu, Error **errp);
+    bool (*cpu_realizefn)(CPUState *cpu, Error **errp);
 } AccelCPUClass;
 
 #endif /* ACCEL_CPU_H */

include/qemu/accel.h

@@ -89,6 +89,6 @@ void accel_cpu_instance_init(CPUState *cpu);
  * @cpu: The CPU that needs to call accel-specific cpu realization.
  * @errp: currently unused.
  */
-void accel_cpu_realizefn(CPUState *cpu, Error **errp);
+bool accel_cpu_realizefn(CPUState *cpu, Error **errp);
 
 #endif /* QEMU_ACCEL_H */

target/i386/host-cpu.c

@@ -80,7 +80,7 @@ static uint32_t host_cpu_adjust_phys_bits(X86CPU *cpu)
     return phys_bits;
 }
 
-void host_cpu_realizefn(CPUState *cs, Error **errp)
+bool host_cpu_realizefn(CPUState *cs, Error **errp)
 {
     X86CPU *cpu = X86_CPU(cs);
     CPUX86State *env = &cpu->env;
@@ -97,10 +97,11 @@ void host_cpu_realizefn(CPUState *cs, Error **errp)
             error_setg(errp, "phys-bits should be between 32 and %u "
                        " (but is %u)",
                        TARGET_PHYS_ADDR_SPACE_BITS, phys_bits);
-            return;
+            return false;
         }
         cpu->phys_bits = phys_bits;
     }
+    return true;
 }
 
 #define CPUID_MODEL_ID_SZ 48

target/i386/host-cpu.h

@@ -12,7 +12,7 @@
 
 void host_cpu_instance_init(X86CPU *cpu);
 void host_cpu_max_instance_init(X86CPU *cpu);
-void host_cpu_realizefn(CPUState *cs, Error **errp);
+bool host_cpu_realizefn(CPUState *cs, Error **errp);
 
 void host_cpu_vendor_fms(char *vendor, int *family, int *model, int *stepping);
 

target/i386/kvm/kvm-cpu.c

@@ -18,7 +18,7 @@
 #include "kvm_i386.h"
 #include "hw/core/accel-cpu.h"
 
-static void kvm_cpu_realizefn(CPUState *cs, Error **errp)
+static bool kvm_cpu_realizefn(CPUState *cs, Error **errp)
 {
     X86CPU *cpu = X86_CPU(cs);
     CPUX86State *env = &cpu->env;
@@ -41,7 +41,7 @@ static void kvm_cpu_realizefn(CPUState *cs, Error **errp)
                                                    MSR_IA32_UCODE_REV);
         }
     }
-    host_cpu_realizefn(cs, errp);
+    return host_cpu_realizefn(cs, errp);
 }
 
 /*

target/i386/tcg/tcg-cpu.c

@@ -96,7 +96,7 @@ static void x86_cpu_machine_done(Notifier *n, void *unused)
     }
 }
 
-static void tcg_cpu_realizefn(CPUState *cs, Error **errp)
+static bool tcg_cpu_realizefn(CPUState *cs, Error **errp)
 {
     X86CPU *cpu = X86_CPU(cs);
 
@@ -132,12 +132,14 @@ static void tcg_cpu_realizefn(CPUState *cs, Error **errp)
     /* ... SMRAM with higher priority, linked from /machine/smram.  */
     cpu->machine_done.notify = x86_cpu_machine_done;
     qemu_add_machine_init_done_notifier(&cpu->machine_done);
+    return true;
 }
 
 #else /* CONFIG_USER_ONLY */
 
-static void tcg_cpu_realizefn(CPUState *cs, Error **errp)
+static bool tcg_cpu_realizefn(CPUState *cs, Error **errp)
 {
+    return true;
 }
 
 #endif /* !CONFIG_USER_ONLY */