[PATCH] Cleanup cpu loop

Gleb Natapov
2009-06-18T12:22:28Z

Rearrange cpu loop to be (hopefully) more readable. Put difference
between kernel/userspace irqchip in one place.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
diff --git a/qemu-kvm.c b/qemu-kvm.c
index 4129fe2..72a081d 100644
--- a/qemu-kvm.c
+++ b/qemu-kvm.c
@@ -1746,15 +1746,9 @@ int kvm_cpu_exec(CPUState *env)
return 0;
}

-static int has_work(CPUState *env)
+static int is_cpu_stopped(CPUState *env)
{
- if (!vm_running || (env && env->kvm_cpu_state.stopped))
- return 0;
- if (kvm_irqchip_in_kernel(kvm_context))
- return 1;
- if (!env->halted)
- return 1;
- return kvm_arch_has_work(env);
+ return !vm_running || env->kvm_cpu_state.stopped;
}

static void flush_queued_work(CPUState *env)
@@ -1877,6 +1871,8 @@ static void update_regs_for_init(CPUState *env)
#endif

cpu_reset(env);
+ /* cpu_reset() clears env->halted, cpu should be halted after init */
+ env->halted = 1;

#ifdef TARGET_I386
/* restore SIPI vector */
@@ -1920,6 +1916,16 @@ static void qemu_kvm_system_reset(void)
resume_all_threads();
}

+static void process_irqchip_events(CPUState *env)
+{
+ if (env->kvm_cpu_state.init)
+ update_regs_for_init(env);
+ if (env->kvm_cpu_state.sipi_needed)
+ update_regs_for_sipi(env);
+ if (kvm_arch_has_work(env))
+ env->halted = 0;
+}
+
static int kvm_main_loop_cpu(CPUState *env)
{
setup_kernel_sigmask(env);
@@ -1935,19 +1941,14 @@ static int kvm_main_loop_cpu(CPUState *env)
kvm_arch_load_regs(env);

while (1) {
- while (!has_work(env))
- kvm_main_loop_wait(env, 1000);
- if (env->interrupt_request & (CPU_INTERRUPT_HARD | CPU_INTERRUPT_NMI))
- env->halted = 0;
- if (!kvm_irqchip_in_kernel(kvm_context)) {
- if (env->kvm_cpu_state.init)
- update_regs_for_init(env);
- if (env->kvm_cpu_state.sipi_needed)
- update_regs_for_sipi(env);
+ int run_cpu = is_cpu_stopped(env) ? 0 : 1;
+ if (run_cpu && !kvm_irqchip_in_kernel(kvm_context)) {
+ process_irqchip_events(env);
+ run_cpu = !env->halted;
}
- if (!env->halted || kvm_irqchip_in_kernel(kvm_context))
- kvm_cpu_exec(env);
- kvm_main_loop_wait(env, 0);
+ kvm_main_loop_wait(env, run_cpu ? 0 : 1000);
+ if (run_cpu)
+ kvm_cpu_exec(env);
}
pthread_mutex_unlock(&qemu_mutex);
return 0;
--
Gleb.