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From: Gleb Natapov <gleb@redhat.com>
To: avi@redhat.com, mtosatti@redhat.com
Cc: kvm@vger.kernel.org
Subject: [PATCH] do not enter vcpu again if it was stopped during IO
Date: Mon, 21 Jun 2010 12:01:52 +0300	[thread overview]
Message-ID: <20100621090152.GG4689@redhat.com> (raw)

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.

             reply	other threads:[~2010-06-21  9:01 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-06-21  9:01 Gleb Natapov [this message]
2010-06-21 20:43 ` [PATCH] do not enter vcpu again if it was stopped during IO Marcelo Tosatti
2010-06-22  5:18   ` Gleb Natapov
2010-06-22 13:59     ` Marcelo Tosatti
2010-06-23  8:22 ` Avi Kivity
2010-06-23  8:24   ` Gleb Natapov
2010-06-23 10:16 ` Jan Kiszka
2010-06-23 10:21   ` Gleb Natapov

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