icount: set can_do_io outside TB execution

This patch sets can_do_io function to allow reading icount
within cpu-exec, but outside TB execution.
Signed-off-by: NPavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

cpu-exec.c

@@ -168,7 +168,9 @@ static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, uint8_t *tb_ptr)
     }
 #endif /* DEBUG_DISAS */
 
+    cpu->can_do_io = 0;
     next_tb = tcg_qemu_tb_exec(env, tb_ptr);
+    cpu->can_do_io = 1;
     trace_exec_tb_exit((void *) (next_tb & ~TB_EXIT_MASK),
                        next_tb & TB_EXIT_MASK);
 
@@ -543,6 +545,7 @@ int cpu_exec(CPUArchState *env)
             cpu = current_cpu;
             env = cpu->env_ptr;
             cc = CPU_GET_CLASS(cpu);
+            cpu->can_do_io = 1;
 #ifdef TARGET_I386
             x86_cpu = X86_CPU(cpu);
 #endif

cpus.c

@@ -935,6 +935,7 @@ static void *qemu_kvm_cpu_thread_fn(void *arg)
     qemu_thread_get_self(cpu->thread);
     cpu->thread_id = qemu_get_thread_id();
     cpu->exception_index = -1;
+    cpu->can_do_io = 1;
     current_cpu = cpu;
 
     r = kvm_init_vcpu(cpu);
@@ -976,6 +977,7 @@ static void *qemu_dummy_cpu_thread_fn(void *arg)
     qemu_thread_get_self(cpu->thread);
     cpu->thread_id = qemu_get_thread_id();
     cpu->exception_index = -1;
+    cpu->can_do_io = 1;
 
     sigemptyset(&waitset);
     sigaddset(&waitset, SIG_IPI);
@@ -1019,6 +1021,7 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
         cpu->thread_id = qemu_get_thread_id();
         cpu->created = true;
         cpu->exception_index = -1;
+        cpu->can_do_io = 1;
     }
     qemu_cond_signal(&qemu_cpu_cond);