target/i386/kvm: Return -1 when kvm_msr_energy_thread_init() fails

It is common practice to return a negative value (like -1) to indicate
an error, and other functions in kvm_arch_init() follow this style.

To avoid confusion (sometimes returned -1 indicates failure, and
sometimes -1, in a same function), return -1 when
kvm_msr_energy_thread_init() fails.

Signed-off-by: Zhao Liu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Bonzini <[email protected]>

Author: trueptolemy

target/i386/kvm/kvm.c

@@ -2936,7 +2936,6 @@ static int kvm_msr_energy_thread_init(KVMState *s, MachineState *ms)
 {
     MachineClass *mc = MACHINE_GET_CLASS(ms);
     struct KVMMsrEnergy *r = &s->msr_energy;
-    int ret = 0;
 
     /*
      * Sanity check
@@ -2946,13 +2945,11 @@ static int kvm_msr_energy_thread_init(KVMState *s, MachineState *ms)
     if (!is_host_cpu_intel()) {
         error_report("The RAPL feature can only be enabled on hosts "
                      "with Intel CPU models");
-        ret = 1;
-        goto out;
+        return -1;
     }
 
     if (!is_rapl_enabled()) {
-        ret = 1;
-        goto out;
+        return -1;
     }
 
     /* Retrieve the virtual topology */
@@ -2974,16 +2971,14 @@ static int kvm_msr_energy_thread_init(KVMState *s, MachineState *ms)
     r->host_topo.maxcpus = vmsr_get_maxcpus();
     if (r->host_topo.maxcpus == 0) {
         error_report("host max cpus = 0");
-        ret = 1;
-        goto out;
+        return -1;
     }
 
     /* Max number of packages on the host */
     r->host_topo.maxpkgs = vmsr_get_max_physical_package(r->host_topo.maxcpus);
     if (r->host_topo.maxpkgs == 0) {
         error_report("host max pkgs = 0");
-        ret = 1;
-        goto out;
+        return -1;
     }
 
     /* Allocate memory for each package on the host */
@@ -2995,8 +2990,7 @@ static int kvm_msr_energy_thread_init(KVMState *s, MachineState *ms)
     for (int i = 0; i < r->host_topo.maxpkgs; i++) {
         if (r->host_topo.pkg_cpu_count[i] == 0) {
             error_report("cpu per packages = 0 on package_%d", i);
-            ret = 1;
-            goto out;
+            return -1;
         }
     }
 
@@ -3013,8 +3007,7 @@ static int kvm_msr_energy_thread_init(KVMState *s, MachineState *ms)
 
     if (s->msr_energy.sioc == NULL) {
         error_report("vmsr socket opening failed");
-        ret = 1;
-        goto out;
+        return -1;
     }
 
     /* Those MSR values should not change */
@@ -3026,15 +3019,13 @@ static int kvm_msr_energy_thread_init(KVMState *s, MachineState *ms)
                                     s->msr_energy.sioc);
     if (r->msr_unit == 0 || r->msr_limit == 0 || r->msr_info == 0) {
         error_report("can't read any virtual msr");
-        ret = 1;
-        goto out;
+        return -1;
     }
 
     qemu_thread_create(&r->msr_thr, "kvm-msr",
                        kvm_msr_energy_thread,
                        s, QEMU_THREAD_JOINABLE);
-out:
-    return ret;
+    return 0;
 }
 
 int kvm_arch_get_default_type(MachineState *ms)
@@ -3342,7 +3333,9 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
 
         if (s->msr_energy.enable == true) {
             kvm_vm_enable_energy_msrs(s);
-            if (kvm_msr_energy_thread_init(s, ms)) {
+
+            ret = kvm_msr_energy_thread_init(s, ms);
+            if (ret < 0) {
                 error_report("kvm : error RAPL feature requirement not met");
                 exit(1);
             }