* [Qemu-devel] [PATCH for-2.9 v3 2/2] virtio-scsi: Fix acquire/release in dataplane handlers
2017-03-17 6:14 [Qemu-devel] [PATCH for-2.9 v3 0/2] virtio-scsi: Fix assertion failure on dataplane handlers Fam Zheng
2017-03-17 6:14 ` [Qemu-devel] [PATCH for-2.9 v3 1/2] virtio-scsi: Make virtio_scsi_acquire/release public Fam Zheng
@ 2017-03-17 6:14 ` Fam Zheng
2017-03-24 10:49 ` [Qemu-devel] [PATCH for-2.9 v3 0/2] virtio-scsi: Fix assertion failure on " Paolo Bonzini
2 siblings, 0 replies; 4+ messages in thread
From: Fam Zheng @ 2017-03-17 6:14 UTC (permalink / raw)
To: qemu-devel; +Cc: Paolo Bonzini, Ed Swierk
After the AioContext lock push down, there is a race between
virtio_scsi_dataplane_start and those "assert(s->ctx &&
s->dataplane_started)", because the latter doesn't isn't wrapped in
aio_context_acquire.
Reproducer is simply booting a Fedora guest with an empty
virtio-scsi-dataplane controller:
qemu-system-x86_64 \
-drive if=none,id=root,format=raw,file=Fedora-Cloud-Base-25-1.3.x86_64.raw \
-device virtio-scsi \
-device scsi-disk,drive=root,bootindex=1 \
-object iothread,id=io \
-device virtio-scsi-pci,iothread=io \
-net user,hostfwd=tcp::10022-:22 -net nic,model=virtio -m 2048 \
--enable-kvm
Fix this by moving acquire/release pairs from virtio_scsi_handle_*_vq to
their callers - and wrap the broken assertions in.
Signed-off-by: Fam Zheng <famz@redhat.com>
---
hw/scsi/virtio-scsi-dataplane.c | 20 ++++++++++++++++----
hw/scsi/virtio-scsi.c | 27 ++++++++++++++-------------
2 files changed, 30 insertions(+), 17 deletions(-)
diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c
index 74c95e0..944ea4e 100644
--- a/hw/scsi/virtio-scsi-dataplane.c
+++ b/hw/scsi/virtio-scsi-dataplane.c
@@ -52,28 +52,40 @@ void virtio_scsi_dataplane_setup(VirtIOSCSI *s, Error **errp)
static bool virtio_scsi_data_plane_handle_cmd(VirtIODevice *vdev,
VirtQueue *vq)
{
- VirtIOSCSI *s = (VirtIOSCSI *)vdev;
+ bool progress;
+ VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+ virtio_scsi_acquire(s);
assert(s->ctx && s->dataplane_started);
- return virtio_scsi_handle_cmd_vq(s, vq);
+ progress = virtio_scsi_handle_cmd_vq(s, vq);
+ virtio_scsi_release(s);
+ return progress;
}
static bool virtio_scsi_data_plane_handle_ctrl(VirtIODevice *vdev,
VirtQueue *vq)
{
+ bool progress;
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+ virtio_scsi_acquire(s);
assert(s->ctx && s->dataplane_started);
- return virtio_scsi_handle_ctrl_vq(s, vq);
+ progress = virtio_scsi_handle_ctrl_vq(s, vq);
+ virtio_scsi_release(s);
+ return progress;
}
static bool virtio_scsi_data_plane_handle_event(VirtIODevice *vdev,
VirtQueue *vq)
{
+ bool progress;
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+ virtio_scsi_acquire(s);
assert(s->ctx && s->dataplane_started);
- return virtio_scsi_handle_event_vq(s, vq);
+ progress = virtio_scsi_handle_event_vq(s, vq);
+ virtio_scsi_release(s);
+ return progress;
}
static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n,
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index e7466d3..bd62d08 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -427,12 +427,10 @@ bool virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s, VirtQueue *vq)
VirtIOSCSIReq *req;
bool progress = false;
- virtio_scsi_acquire(s);
while ((req = virtio_scsi_pop_req(s, vq))) {
progress = true;
virtio_scsi_handle_ctrl_req(s, req);
}
- virtio_scsi_release(s);
return progress;
}
@@ -446,7 +444,9 @@ static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
return;
}
}
+ virtio_scsi_acquire(s);
virtio_scsi_handle_ctrl_vq(s, vq);
+ virtio_scsi_release(s);
}
static void virtio_scsi_complete_cmd_req(VirtIOSCSIReq *req)
@@ -590,7 +590,6 @@ bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
- virtio_scsi_acquire(s);
do {
virtio_queue_set_notification(vq, 0);
@@ -618,7 +617,6 @@ bool virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
virtio_scsi_handle_cmd_req_submit(s, req);
}
- virtio_scsi_release(s);
return progress;
}
@@ -633,7 +631,9 @@ static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
return;
}
}
+ virtio_scsi_acquire(s);
virtio_scsi_handle_cmd_vq(s, vq);
+ virtio_scsi_release(s);
}
static void virtio_scsi_get_config(VirtIODevice *vdev,
@@ -709,12 +709,10 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
return;
}
- virtio_scsi_acquire(s);
-
req = virtio_scsi_pop_req(s, vs->event_vq);
if (!req) {
s->events_dropped = true;
- goto out;
+ return;
}
if (s->events_dropped) {
@@ -724,7 +722,7 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
if (virtio_scsi_parse_req(req, 0, sizeof(VirtIOSCSIEvent))) {
virtio_scsi_bad_req(req);
- goto out;
+ return;
}
evt = &req->resp.event;
@@ -744,19 +742,14 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
evt->lun[3] = dev->lun & 0xFF;
}
virtio_scsi_complete_req(req);
-out:
- virtio_scsi_release(s);
}
bool virtio_scsi_handle_event_vq(VirtIOSCSI *s, VirtQueue *vq)
{
- virtio_scsi_acquire(s);
if (s->events_dropped) {
virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
- virtio_scsi_release(s);
return true;
}
- virtio_scsi_release(s);
return false;
}
@@ -770,7 +763,9 @@ static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
return;
}
}
+ virtio_scsi_acquire(s);
virtio_scsi_handle_event_vq(s, vq);
+ virtio_scsi_release(s);
}
static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
@@ -780,8 +775,10 @@ static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_CHANGE) &&
dev->type != TYPE_ROM) {
+ virtio_scsi_acquire(s);
virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
sense.asc | (sense.ascq << 8));
+ virtio_scsi_release(s);
}
}
@@ -803,9 +800,11 @@ static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
}
if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
+ virtio_scsi_acquire(s);
virtio_scsi_push_event(s, sd,
VIRTIO_SCSI_T_TRANSPORT_RESET,
VIRTIO_SCSI_EVT_RESET_RESCAN);
+ virtio_scsi_release(s);
}
}
@@ -817,9 +816,11 @@ static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
SCSIDevice *sd = SCSI_DEVICE(dev);
if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
+ virtio_scsi_acquire(s);
virtio_scsi_push_event(s, sd,
VIRTIO_SCSI_T_TRANSPORT_RESET,
VIRTIO_SCSI_EVT_RESET_REMOVED);
+ virtio_scsi_release(s);
}
qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
--
2.9.3
^ permalink raw reply related [flat|nested] 4+ messages in thread