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-rw-r--r--hw/scsi/virtio-scsi.c169
-rw-r--r--include/hw/virtio/virtio-scsi.h11
2 files changed, 143 insertions, 37 deletions
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index 2b649ca..612c525 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -43,13 +43,11 @@ typedef struct VirtIOSCSIReq {
QEMUSGList qsgl;
QEMUIOVector resp_iov;
- union {
- /* Used for two-stage request submission */
- QTAILQ_ENTRY(VirtIOSCSIReq) next;
+ /* Used for two-stage request submission and TMFs deferred to BH */
+ QTAILQ_ENTRY(VirtIOSCSIReq) next;
- /* Used for cancellation of request during TMFs */
- int remaining;
- };
+ /* Used for cancellation of request during TMFs */
+ int remaining;
SCSIRequest *sreq;
size_t resp_size;
@@ -294,6 +292,122 @@ static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
}
}
+static void virtio_scsi_do_one_tmf_bh(VirtIOSCSIReq *req)
+{
+ VirtIOSCSI *s = req->dev;
+ SCSIDevice *d = virtio_scsi_device_get(s, req->req.tmf.lun);
+ BusChild *kid;
+ int target;
+
+ switch (req->req.tmf.subtype) {
+ case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
+ if (!d) {
+ req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
+ goto out;
+ }
+ if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
+ req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
+ goto out;
+ }
+ qatomic_inc(&s->resetting);
+ device_cold_reset(&d->qdev);
+ qatomic_dec(&s->resetting);
+ break;
+
+ case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
+ target = req->req.tmf.lun[1];
+ qatomic_inc(&s->resetting);
+
+ rcu_read_lock();
+ QTAILQ_FOREACH_RCU(kid, &s->bus.qbus.children, sibling) {
+ SCSIDevice *d1 = SCSI_DEVICE(kid->child);
+ if (d1->channel == 0 && d1->id == target) {
+ device_cold_reset(&d1->qdev);
+ }
+ }
+ rcu_read_unlock();
+
+ qatomic_dec(&s->resetting);
+ break;
+
+ default:
+ g_assert_not_reached();
+ break;
+ }
+
+out:
+ object_unref(OBJECT(d));
+
+ virtio_scsi_acquire(s);
+ virtio_scsi_complete_req(req);
+ virtio_scsi_release(s);
+}
+
+/* Some TMFs must be processed from the main loop thread */
+static void virtio_scsi_do_tmf_bh(void *opaque)
+{
+ VirtIOSCSI *s = opaque;
+ QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
+ VirtIOSCSIReq *req;
+ VirtIOSCSIReq *tmp;
+
+ GLOBAL_STATE_CODE();
+
+ virtio_scsi_acquire(s);
+
+ QTAILQ_FOREACH_SAFE(req, &s->tmf_bh_list, next, tmp) {
+ QTAILQ_REMOVE(&s->tmf_bh_list, req, next);
+ QTAILQ_INSERT_TAIL(&reqs, req, next);
+ }
+
+ qemu_bh_delete(s->tmf_bh);
+ s->tmf_bh = NULL;
+
+ virtio_scsi_release(s);
+
+ QTAILQ_FOREACH_SAFE(req, &reqs, next, tmp) {
+ QTAILQ_REMOVE(&reqs, req, next);
+ virtio_scsi_do_one_tmf_bh(req);
+ }
+}
+
+static void virtio_scsi_reset_tmf_bh(VirtIOSCSI *s)
+{
+ VirtIOSCSIReq *req;
+ VirtIOSCSIReq *tmp;
+
+ GLOBAL_STATE_CODE();
+
+ virtio_scsi_acquire(s);
+
+ if (s->tmf_bh) {
+ qemu_bh_delete(s->tmf_bh);
+ s->tmf_bh = NULL;
+ }
+
+ QTAILQ_FOREACH_SAFE(req, &s->tmf_bh_list, next, tmp) {
+ QTAILQ_REMOVE(&s->tmf_bh_list, req, next);
+
+ /* SAM-6 6.3.2 Hard reset */
+ req->resp.tmf.response = VIRTIO_SCSI_S_TARGET_FAILURE;
+ virtio_scsi_complete_req(req);
+ }
+
+ virtio_scsi_release(s);
+}
+
+static void virtio_scsi_defer_tmf_to_bh(VirtIOSCSIReq *req)
+{
+ VirtIOSCSI *s = req->dev;
+
+ QTAILQ_INSERT_TAIL(&s->tmf_bh_list, req, next);
+
+ if (!s->tmf_bh) {
+ s->tmf_bh = qemu_bh_new(virtio_scsi_do_tmf_bh, s);
+ qemu_bh_schedule(s->tmf_bh);
+ }
+}
+
/* Return 0 if the request is ready to be completed and return to guest;
* -EINPROGRESS if the request is submitted and will be completed later, in the
* case of async cancellation. */
@@ -301,8 +415,6 @@ static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
{
SCSIDevice *d = virtio_scsi_device_get(s, req->req.tmf.lun);
SCSIRequest *r, *next;
- BusChild *kid;
- int target;
int ret = 0;
virtio_scsi_ctx_check(s, d);
@@ -359,15 +471,9 @@ static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
break;
case VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET:
- if (!d) {
- goto fail;
- }
- if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
- goto incorrect_lun;
- }
- s->resetting++;
- device_cold_reset(&d->qdev);
- s->resetting--;
+ case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
+ virtio_scsi_defer_tmf_to_bh(req);
+ ret = -EINPROGRESS;
break;
case VIRTIO_SCSI_T_TMF_ABORT_TASK_SET:
@@ -410,22 +516,6 @@ static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
}
break;
- case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
- target = req->req.tmf.lun[1];
- s->resetting++;
-
- rcu_read_lock();
- QTAILQ_FOREACH_RCU(kid, &s->bus.qbus.children, sibling) {
- SCSIDevice *d1 = SCSI_DEVICE(kid->child);
- if (d1->channel == 0 && d1->id == target) {
- device_cold_reset(&d1->qdev);
- }
- }
- rcu_read_unlock();
-
- s->resetting--;
- break;
-
case VIRTIO_SCSI_T_TMF_CLEAR_ACA:
default:
req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
@@ -655,7 +745,7 @@ static void virtio_scsi_request_cancelled(SCSIRequest *r)
if (!req) {
return;
}
- if (req->dev->resetting) {
+ if (qatomic_read(&req->dev->resetting)) {
req->resp.cmd.response = VIRTIO_SCSI_S_RESET;
} else {
req->resp.cmd.response = VIRTIO_SCSI_S_ABORTED;
@@ -831,9 +921,12 @@ static void virtio_scsi_reset(VirtIODevice *vdev)
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
assert(!s->dataplane_started);
- s->resetting++;
+
+ virtio_scsi_reset_tmf_bh(s);
+
+ qatomic_inc(&s->resetting);
bus_cold_reset(BUS(&s->bus));
- s->resetting--;
+ qatomic_dec(&s->resetting);
vs->sense_size = VIRTIO_SCSI_SENSE_DEFAULT_SIZE;
vs->cdb_size = VIRTIO_SCSI_CDB_DEFAULT_SIZE;
@@ -1053,6 +1146,8 @@ static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
VirtIOSCSI *s = VIRTIO_SCSI(dev);
Error *err = NULL;
+ QTAILQ_INIT(&s->tmf_bh_list);
+
virtio_scsi_common_realize(dev,
virtio_scsi_handle_ctrl,
virtio_scsi_handle_event,
@@ -1090,6 +1185,8 @@ static void virtio_scsi_device_unrealize(DeviceState *dev)
{
VirtIOSCSI *s = VIRTIO_SCSI(dev);
+ virtio_scsi_reset_tmf_bh(s);
+
qbus_set_hotplug_handler(BUS(&s->bus), NULL);
virtio_scsi_common_unrealize(dev);
}
diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h
index 37b75e1..779568a 100644
--- a/include/hw/virtio/virtio-scsi.h
+++ b/include/hw/virtio/virtio-scsi.h
@@ -74,13 +74,22 @@ struct VirtIOSCSICommon {
VirtQueue **cmd_vqs;
};
+struct VirtIOSCSIReq;
+
struct VirtIOSCSI {
VirtIOSCSICommon parent_obj;
SCSIBus bus;
- int resetting;
+ int resetting; /* written from main loop thread, read from any thread */
bool events_dropped;
+ /*
+ * TMFs deferred to main loop BH. These fields are protected by
+ * virtio_scsi_acquire().
+ */
+ QEMUBH *tmf_bh;
+ QTAILQ_HEAD(, VirtIOSCSIReq) tmf_bh_list;
+
/* Fields for dataplane below */
AioContext *ctx; /* one iothread per virtio-scsi-pci for now */
generated by cgit v1.1 at 2024-12-26 13:16:44 +0000