Simplify the various dataplane stages in dataplane_start/stop by using
a single enum instead of having multiple flags.
Read/write the enum atomically, as it can be read also by iothread
callbacks.
Signed-off-by: Emanuele Giuseppe Esposito <eespo...@redhat.com>
---
hw/scsi/virtio-scsi-dataplane.c | 21 +++++++++------------
hw/scsi/virtio-scsi.c | 10 ++++++----
include/hw/virtio/virtio-scsi.h | 5 ++---
include/hw/virtio/virtio.h | 7 +++++++
4 files changed, 24 insertions(+), 19 deletions(-)
diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c
index a575c3f0cd..9ad73e3e19 100644
--- a/hw/scsi/virtio-scsi-dataplane.c
+++ b/hw/scsi/virtio-scsi-dataplane.c
@@ -106,13 +106,12 @@ int virtio_scsi_dataplane_start(VirtIODevice *vdev)
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
- if (s->dataplane_started ||
- s->dataplane_starting ||
+ if (qatomic_read(&s->dataplane_state) <= DATAPLANE_STARTED ||
s->dataplane_fenced) {
return 0;
}
- s->dataplane_starting = true;
+ qatomic_set(&s->dataplane_state, DATAPLANE_STARTING);
/* Set up guest notifier (irq) */
rc = k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, true);
@@ -151,8 +150,7 @@ int virtio_scsi_dataplane_start(VirtIODevice *vdev)
memory_region_transaction_commit();
- s->dataplane_starting = false;
- s->dataplane_started = true;
+ qatomic_set(&s->dataplane_state, DATAPLANE_STARTED);
/*
* Attach notifiers from within the IOThread. It's possible to attach
@@ -183,8 +181,8 @@ fail_host_notifiers:
k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
fail_guest_notifiers:
s->dataplane_fenced = true;
- s->dataplane_starting = false;
- s->dataplane_started = true;
+ qatomic_set(&s->dataplane_state, DATAPLANE_STARTED);
+
return -ENOSYS;
}
@@ -197,17 +195,17 @@ void virtio_scsi_dataplane_stop(VirtIODevice *vdev)
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
int i;
- if (!s->dataplane_started || s->dataplane_stopping) {
+ if (qatomic_read(&s->dataplane_state) != DATAPLANE_STARTED) {
return;
}
/* Better luck next time. */
if (s->dataplane_fenced) {
s->dataplane_fenced = false;
- s->dataplane_started = false;
+ qatomic_set(&s->dataplane_state, DATAPLANE_STOPPED);
return;
}
- s->dataplane_stopping = true;
+ qatomic_set(&s->dataplane_state, DATAPLANE_STOPPING);
aio_context_acquire(s->ctx);
aio_wait_bh_oneshot(s->ctx, virtio_scsi_dataplane_stop_bh, s);
@@ -237,6 +235,5 @@ void virtio_scsi_dataplane_stop(VirtIODevice *vdev)
/* Clean up guest notifier (irq) */
k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
- s->dataplane_stopping = false;
- s->dataplane_started = false;
+ qatomic_set(&s->dataplane_state, DATAPLANE_STOPPED);
}
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index 4141dddd51..e6ff667e86 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -110,7 +110,8 @@ static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
- if (s->dataplane_started && !s->dataplane_fenced) {
+ if (qatomic_read(&s->dataplane_state) == DATAPLANE_STARTED &&
+ !s->dataplane_fenced) {
virtio_notify_irqfd(vdev, vq);
} else {
virtio_notify(vdev, vq);
@@ -288,7 +289,8 @@ static void virtio_scsi_cancel_notify(Notifier *notifier,
void *data)
static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
{
- if (s->dataplane_started && d && blk_is_available(d->conf.blk)) {
+ if (qatomic_read(&s->dataplane_state) == DATAPLANE_STARTED && d &&
+ blk_is_available(d->conf.blk)) {
assert(blk_get_aio_context(d->conf.blk) == s->ctx);
}
}
@@ -516,7 +518,7 @@ static void virtio_scsi_handle_ctrl_vq(VirtIOSCSI *s,
VirtQueue *vq)
*/
static bool virtio_scsi_defer_to_dataplane(VirtIOSCSI *s)
{
- if (!s->ctx || s->dataplane_started) {
+ if (!s->ctx || qatomic_read(&s->dataplane_state) <= DATAPLANE_STARTED) {
return false;
}
@@ -828,7 +830,7 @@ static void virtio_scsi_reset(VirtIODevice *vdev)
VirtIOSCSI *s = VIRTIO_SCSI(vdev);
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
- assert(!s->dataplane_started);
+ assert(qatomic_read(&s->dataplane_state) != DATAPLANE_STARTED);
s->resetting++;
qbus_reset_all(BUS(&s->bus));
s->resetting--;
diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h
index a36aad9c86..e9e922dff4 100644
--- a/include/hw/virtio/virtio-scsi.h
+++ b/include/hw/virtio/virtio-scsi.h
@@ -85,9 +85,8 @@ struct VirtIOSCSI {
/* Fields for dataplane below */
AioContext *ctx; /* one iothread per virtio-scsi-pci for now */
- bool dataplane_started;
- bool dataplane_starting;
- bool dataplane_stopping;
+ enum VirtIODataplaneStates dataplane_state;
+
bool dataplane_fenced;
uint32_t host_features;
};
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index db1c0ddf6b..25d1515570 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -71,6 +71,13 @@ typedef struct VirtQueueElement
#define TYPE_VIRTIO_DEVICE "virtio-device"
OBJECT_DECLARE_TYPE(VirtIODevice, VirtioDeviceClass, VIRTIO_DEVICE)
+enum VirtIODataplaneStates {
+ DATAPLANE_STARTING, /* dataplane is being initialized */
+ DATAPLANE_STARTED, /* dataplane has been intialized */
+ DATAPLANE_STOPPING, /* dataplane is being stopped */
+ DATAPLANE_STOPPED, /* dataplane is stopped */
+};
+
enum virtio_device_endian {
VIRTIO_DEVICE_ENDIAN_UNKNOWN,
VIRTIO_DEVICE_ENDIAN_LITTLE,
--
2.31.1
