From 02891ca4ab9cfc18237143b9a078eb2961aea9c6 Mon Sep 17 00:00:00 2001
From: Fam Zheng <famz@redhat.com>
Date: Wed, 14 Sep 2016 02:38:45 +0200
Subject: [PATCH 02/18] iothread: Stop threads before main() quits
RH-Author: Fam Zheng <famz@redhat.com>
Message-id: <1473820725-8539-1-git-send-email-famz@redhat.com>
Patchwork-id: 72301
O-Subject: [RHEV-7.3 qemu-kvm-rhev PATCH] iothread: Stop threads before main() quits
Bugzilla: 1343021
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1343021
Brew: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=11748295
Right after main_loop ends, we release various things but keep iothread
alive. The latter is not prepared to the sudden change of resources.
Specifically, after bdrv_close_all(), virtio-scsi dataplane get a
surprise at the empty BlockBackend:
(gdb) bt
at /usr/src/debug/qemu-2.6.0/hw/scsi/virtio-scsi.c:543
at /usr/src/debug/qemu-2.6.0/hw/scsi/virtio-scsi.c:577
It is because the d->conf.blk->root is set to NULL, then
blk_get_aio_context() returns qemu_aio_context, whereas s->ctx is still
pointing to the iothread:
hw/scsi/virtio-scsi.c:543:
if (s->dataplane_started) {
assert(blk_get_aio_context(d->conf.blk) == s->ctx);
}
To fix this, let's stop iothreads before doing bdrv_close_all().
Cc: qemu-stable@nongnu.org
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1473326931-9699-1-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit dce8921b2baaf95974af8176406881872067adfa)
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
include/sysemu/iothread.h | 1 +
iothread.c | 24 ++++++++++++++++++++----
vl.c | 2 ++
3 files changed, 23 insertions(+), 4 deletions(-)
diff --git a/include/sysemu/iothread.h b/include/sysemu/iothread.h
index 2eefea1..68ac2de 100644
--- a/include/sysemu/iothread.h
+++ b/include/sysemu/iothread.h
@@ -35,5 +35,6 @@ typedef struct {
char *iothread_get_id(IOThread *iothread);
AioContext *iothread_get_aio_context(IOThread *iothread);
+void iothread_stop_all(void);
#endif /* IOTHREAD_H */
diff --git a/iothread.c b/iothread.c
index f183d38..fb08a60 100644
--- a/iothread.c
+++ b/iothread.c
@@ -54,16 +54,25 @@ static void *iothread_run(void *opaque)
return NULL;
}
-static void iothread_instance_finalize(Object *obj)
+static int iothread_stop(Object *object, void *opaque)
{
- IOThread *iothread = IOTHREAD(obj);
+ IOThread *iothread;
- if (!iothread->ctx) {
- return;
+ iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD);
+ if (!iothread || !iothread->ctx) {
+ return 0;
}
iothread->stopping = true;
aio_notify(iothread->ctx);
qemu_thread_join(&iothread->thread);
+ return 0;
+}
+
+static void iothread_instance_finalize(Object *obj)
+{
+ IOThread *iothread = IOTHREAD(obj);
+
+ iothread_stop(obj, NULL);
qemu_cond_destroy(&iothread->init_done_cond);
qemu_mutex_destroy(&iothread->init_done_lock);
aio_context_unref(iothread->ctx);
@@ -174,3 +183,10 @@ IOThreadInfoList *qmp_query_iothreads(Error **errp)
object_child_foreach(container, query_one_iothread, &prev);
return head;
}
+
+void iothread_stop_all(void)
+{
+ Object *container = object_get_objects_root();
+
+ object_child_foreach(container, iothread_stop, NULL);
+}
diff --git a/vl.c b/vl.c
index 862b13d..0e23313 100644
--- a/vl.c
+++ b/vl.c
@@ -119,6 +119,7 @@ int main(int argc, char **argv)
#include "crypto/init.h"
#include "sysemu/replay.h"
#include "qapi/qmp/qerror.h"
+#include "sysemu/iothread.h"
#define MAX_VIRTIO_CONSOLES 1
#define MAX_SCLP_CONSOLES 1
@@ -4691,6 +4692,7 @@ int main(int argc, char **argv, char **envp)
main_loop();
replay_disable_events();
+ iothread_stop_all();
bdrv_close_all();
pause_all_vcpus();
--
1.8.3.1