[PATCH 01/37] Prevent abortion on multiple VCPU kicks

Marcelo Tosatti
2011-02-14T15:25:01Z

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(-)

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)
--
1.7.4