Patchwork [01/23] Prevent abortion on multiple VCPU kicks

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Submitter Marcelo Tosatti
Date Feb. 4, 2011, 3:47 p.m.
Message ID <8233476ad02b9b01d53a246851f7139698ff55fa.1296834446.git.mtosatti@redhat.com>
Download mbox | patch
Permalink /patch/81910/
State New
Headers show

Comments

Marcelo Tosatti - Feb. 4, 2011, 3:47 p.m.
From: Jan Kiszka <jan.kiszka@siemens.com>

If we call qemu_cpu_kick more than once before the target was able to
process the signal, pthread_kill will fail, and qemu will abort. Prevent
this by avoiding the redundant signal.

This logic can be found in qemu-kvm as well.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---
 cpu-defs.h |    1 +
 cpus.c     |    6 +++++-
 2 files changed, 6 insertions(+), 1 deletions(-)

Patch

diff --git a/cpu-defs.h b/cpu-defs.h
index 8d4bf86..db809ed 100644
--- a/cpu-defs.h
+++ b/cpu-defs.h
@@ -205,6 +205,7 @@  typedef struct CPUWatchpoint {
     uint32_t stopped; /* Artificially stopped */                        \
     struct QemuThread *thread;                                          \
     struct QemuCond *halt_cond;                                         \
+    int thread_kicked;                                                  \
     struct qemu_work_item *queued_work_first, *queued_work_last;        \
     const char *cpu_model_str;                                          \
     struct KVMState *kvm_state;                                         \
diff --git a/cpus.c b/cpus.c
index 4c9928e..ab6e40e 100644
--- a/cpus.c
+++ b/cpus.c
@@ -481,6 +481,7 @@  static void qemu_wait_io_event_common(CPUState *env)
         qemu_cond_signal(&qemu_pause_cond);
     }
     flush_queued_work(env);
+    env->thread_kicked = false;
 }
 
 static void qemu_tcg_wait_io_event(void)
@@ -648,7 +649,10 @@  void qemu_cpu_kick(void *_env)
 {
     CPUState *env = _env;
     qemu_cond_broadcast(env->halt_cond);
-    qemu_thread_signal(env->thread, SIG_IPI);
+    if (!env->thread_kicked) {
+        qemu_thread_signal(env->thread, SIG_IPI);
+        env->thread_kicked = true;
+    }
 }
 
 int qemu_cpu_self(void *_env)