cpu: Replace cpu_single_env with CPUState current_cpu

Move it to qom/cpu.h.

Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/hw/i386/kvmvapic.c b/hw/i386/kvmvapic.c
index 9850a85..e13678f 100644
--- a/hw/i386/kvmvapic.c
+++ b/hw/i386/kvmvapic.c
@@ -624,11 +624,13 @@
 static void vapic_write(void *opaque, hwaddr addr, uint64_t data,
                         unsigned int size)
 {
-    CPUX86State *env = cpu_single_env;
+    CPUState *cs = current_cpu;
+    X86CPU *cpu = X86_CPU(cs);
+    CPUX86State *env = &cpu->env;
     hwaddr rom_paddr;
     VAPICROMState *s = opaque;
 
-    cpu_synchronize_state(CPU(x86_env_get_cpu(env)));
+    cpu_synchronize_state(cs);
 
     /*
      * The VAPIC supports two PIO-based hypercalls, both via port 0x7E.
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index e00f9dc..5224256 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -886,8 +886,9 @@
 
 DeviceState *cpu_get_current_apic(void)
 {
-    if (cpu_single_env) {
-        return cpu_single_env->apic_state;
+    if (current_cpu) {
+        X86CPU *cpu = X86_CPU(current_cpu);
+        return cpu->env.apic_state;
     } else {
         return NULL;
     }
@@ -1176,10 +1177,10 @@
 
 static void cpu_request_exit(void *opaque, int irq, int level)
 {
-    CPUX86State *env = cpu_single_env;
+    CPUState *cpu = current_cpu;
 
-    if (env && level) {
-        cpu_exit(CPU(x86_env_get_cpu(env)));
+    if (cpu && level) {
+        cpu_exit(cpu);
     }
 }