From 02891ca4ab9cfc18237143b9a078eb2961aea9c6 Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Wed, 14 Sep 2016 02:38:45 +0200 Subject: [PATCH 02/18] iothread: Stop threads before main() quits RH-Author: Fam Zheng 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 RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Miroslav Rezanina 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 Reviewed-by: Paolo Bonzini Message-id: 1473326931-9699-1-git-send-email-famz@redhat.com Signed-off-by: Stefan Hajnoczi (cherry picked from commit dce8921b2baaf95974af8176406881872067adfa) Signed-off-by: Fam Zheng Signed-off-by: Miroslav Rezanina --- 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