[PATCH] do not enter vcpu again if it was stopped during IO

Gleb Natapov
2010-06-21T09:01:58Z

To prevent reentering vcpu after IO completion it is not enough
to set env->stopped since it is checked only in main loop but control
will not get there until next non-IO exit since kvm_run() will reenter
vcpu to complete IO instruction. Solve this by sending self-signal to
request exit after IO instruction completion.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
diff --git a/qemu-kvm.c b/qemu-kvm.c
index be1dac2..4f7cf6d 100644
--- a/qemu-kvm.c
+++ b/qemu-kvm.c
@@ -603,6 +603,10 @@ int kvm_run(CPUState *env)
r = pre_kvm_run(kvm, env);
if (r)
return r;
+ if (env->exit_request) {
+ env->exit_request = 0;
+ pthread_kill(env->kvm_cpu_state.thread, SIG_IPI);
+ }
r = ioctl(fd, KVM_RUN, 0);

if (r == -1 && errno != EINTR && errno != EAGAIN) {
diff --git a/vl.c b/vl.c
index 9e9c176..dcfab13 100644
--- a/vl.c
+++ b/vl.c
@@ -1817,6 +1817,7 @@ void qemu_system_reset_request(void)
}
if (cpu_single_env) {
cpu_single_env->stopped = 1;
+ cpu_exit(cpu_single_env);
}
qemu_notify_event();
}
--
Gleb.