1 files changed, 10 insertions, 2 deletions
diff --git a/cpus.c b/cpus.c
index abd24ab31c..3035314486 100644
--- a/cpus.c
+++ b/cpus.c
@@ -396,12 +396,19 @@ static int qemu_signal_init(void)
     sigaddset(&set, SIGUSR2);
     pthread_sigmask(SIG_UNBLOCK, &set, NULL);
 
+    /*
+     * SIG_IPI must be blocked in the main thread and must not be caught
+     * by sigwait() in the signal thread. Otherwise, the cpu thread will
+     * not catch it reliably.
+     */
+    sigemptyset(&set);
+    sigaddset(&set, SIG_IPI);
+    pthread_sigmask(SIG_BLOCK, &set, NULL);
+
     sigemptyset(&set);
     sigaddset(&set, SIGIO);
     sigaddset(&set, SIGALRM);
-    sigaddset(&set, SIG_IPI);
     sigaddset(&set, SIGBUS);
-    pthread_sigmask(SIG_BLOCK, &set, NULL);
 #else
     sigemptyset(&set);
     sigaddset(&set, SIGBUS);
@@ -414,6 +421,7 @@ static int qemu_signal_init(void)
         sigaddset(&set, SIGALRM);
     }
 #endif
+    pthread_sigmask(SIG_BLOCK, &set, NULL);
 
     sigfd = qemu_signalfd(&set);
     if (sigfd == -1) {