2 files changed, 94 insertions, 144 deletions

diff --git a/qemu/hw/block/dataplane/virtio-blk.c b/qemu/hw/block/dataplane/virtio-blk.c
index 6106e4615..3cb97c9a2 100644
--- a/qemu/hw/block/dataplane/virtio-blk.c
+++ b/qemu/hw/block/dataplane/virtio-blk.c
@@ -12,13 +12,13 @@
  *
  */
 
+#include "qemu/osdep.h"
+#include "qapi/error.h"
 #include "trace.h"
 #include "qemu/iov.h"
 #include "qemu/thread.h"
 #include "qemu/error-report.h"
 #include "hw/virtio/virtio-access.h"
-#include "hw/virtio/dataplane/vring.h"
-#include "hw/virtio/dataplane/vring-accessors.h"
 #include "sysemu/block-backend.h"
 #include "hw/virtio/virtio-blk.h"
 #include "virtio-blk.h"
@@ -27,114 +27,93 @@
 #include "qom/object_interfaces.h"
 
 struct VirtIOBlockDataPlane {
-    bool started;
     bool starting;
     bool stopping;
-    bool disabled;
 
     VirtIOBlkConf *conf;
 
     VirtIODevice *vdev;
-    Vring vring;                    /* virtqueue vring */
+    VirtQueue *vq;                  /* virtqueue vring */
     EventNotifier *guest_notifier;  /* irq */
     QEMUBH *bh;                     /* bh for guest notification */
 
+    Notifier insert_notifier, remove_notifier;
+
     /* Note that these EventNotifiers are assigned by value.  This is
      * fine as long as you do not call event_notifier_cleanup on them
      * (because you don't own the file descriptor or handle; you just
      * use it).
      */
     IOThread *iothread;
-    IOThread internal_iothread_obj;
     AioContext *ctx;
-    EventNotifier host_notifier;    /* doorbell */
 
     /* Operation blocker on BDS */
     Error *blocker;
-    void (*saved_complete_request)(struct VirtIOBlockReq *req,
-                                   unsigned char status);
 };
 
 /* Raise an interrupt to signal guest, if necessary */
-static void notify_guest(VirtIOBlockDataPlane *s)
+void virtio_blk_data_plane_notify(VirtIOBlockDataPlane *s)
 {
-    if (!vring_should_notify(s->vdev, &s->vring)) {
-        return;
-    }
-
-    event_notifier_set(s->guest_notifier);
+    qemu_bh_schedule(s->bh);
 }
 
 static void notify_guest_bh(void *opaque)
 {
     VirtIOBlockDataPlane *s = opaque;
 
-    notify_guest(s);
+    if (!virtio_should_notify(s->vdev, s->vq)) {
+        return;
+    }
+
+    event_notifier_set(s->guest_notifier);
 }
 
-static void complete_request_vring(VirtIOBlockReq *req, unsigned char status)
+static void data_plane_set_up_op_blockers(VirtIOBlockDataPlane *s)
 {
-    VirtIOBlockDataPlane *s = req->dev->dataplane;
-    stb_p(&req->in->status, status);
-
-    vring_push(s->vdev, &req->dev->dataplane->vring, &req->elem, req->in_len);
+    assert(!s->blocker);
+    error_setg(&s->blocker, "block device is in use by data plane");
+    blk_op_block_all(s->conf->conf.blk, s->blocker);
+    blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_RESIZE, s->blocker);
+    blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_DRIVE_DEL, s->blocker);
+    blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_BACKUP_SOURCE, s->blocker);
+    blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_CHANGE, s->blocker);
+    blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_COMMIT_SOURCE, s->blocker);
+    blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_COMMIT_TARGET, s->blocker);
+    blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_EJECT, s->blocker);
+    blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT,
+                   s->blocker);
+    blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT,
+                   s->blocker);
+    blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
+                   s->blocker);
+    blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_MIRROR_SOURCE, s->blocker);
+    blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_STREAM, s->blocker);
+    blk_op_unblock(s->conf->conf.blk, BLOCK_OP_TYPE_REPLACE, s->blocker);
+}
 
-    /* Suppress notification to guest by BH and its scheduled
-     * flag because requests are completed as a batch after io
-     * plug & unplug is introduced, and the BH can still be
-     * executed in dataplane aio context even after it is
-     * stopped, so needn't worry about notification loss with BH.
-     */
-    qemu_bh_schedule(s->bh);
+static void data_plane_remove_op_blockers(VirtIOBlockDataPlane *s)
+{
+    if (s->blocker) {
+        blk_op_unblock_all(s->conf->conf.blk, s->blocker);
+        error_free(s->blocker);
+        s->blocker = NULL;
+    }
 }
 
-static void handle_notify(EventNotifier *e)
+static void data_plane_blk_insert_notifier(Notifier *n, void *data)
 {
-    VirtIOBlockDataPlane *s = container_of(e, VirtIOBlockDataPlane,
-                                           host_notifier);
-    VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
+    VirtIOBlockDataPlane *s = container_of(n, VirtIOBlockDataPlane,
+                                           insert_notifier);
+    assert(s->conf->conf.blk == data);
+    data_plane_set_up_op_blockers(s);
+}
 
-    event_notifier_test_and_clear(&s->host_notifier);
-    blk_io_plug(s->conf->conf.blk);
-    for (;;) {
-        MultiReqBuffer mrb = {};
-        int ret;
-
-        /* Disable guest->host notifies to avoid unnecessary vmexits */
-        vring_disable_notification(s->vdev, &s->vring);
-
-        for (;;) {
-            VirtIOBlockReq *req = virtio_blk_alloc_request(vblk);
-
-            ret = vring_pop(s->vdev, &s->vring, &req->elem);
-            if (ret < 0) {
-                virtio_blk_free_request(req);
-                break; /* no more requests */
-            }
-
-            trace_virtio_blk_data_plane_process_request(s, req->elem.out_num,
-                                                        req->elem.in_num,
-                                                        req->elem.index);
-
-            virtio_blk_handle_request(req, &mrb);
-        }
-
-        if (mrb.num_reqs) {
-            virtio_blk_submit_multireq(s->conf->conf.blk, &mrb);
-        }
-
-        if (likely(ret == -EAGAIN)) { /* vring emptied */
-            /* Re-enable guest->host notifies and stop processing the vring.
-             * But if the guest has snuck in more descriptors, keep processing.
-             */
-            if (vring_enable_notification(s->vdev, &s->vring)) {
-                break;
-            }
-        } else { /* fatal error */
-            break;
-        }
-    }
-    blk_io_unplug(s->conf->conf.blk);
+static void data_plane_blk_remove_notifier(Notifier *n, void *data)
+{
+    VirtIOBlockDataPlane *s = container_of(n, VirtIOBlockDataPlane,
+                                           remove_notifier);
+    assert(s->conf->conf.blk == data);
+    data_plane_remove_op_blockers(s);
 }
 
 /* Context: QEMU global mutex held */
@@ -143,20 +122,19 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
                                   Error **errp)
 {
     VirtIOBlockDataPlane *s;
-    Error *local_err = NULL;
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
 
     *dataplane = NULL;
 
-    if (!conf->data_plane && !conf->iothread) {
+    if (!conf->iothread) {
         return;
     }
 
     /* Don't try if transport does not support notifiers. */
     if (!k->set_guest_notifiers || !k->set_host_notifier) {
         error_setg(errp,
-                   "device is incompatible with x-data-plane "
+                   "device is incompatible with dataplane "
                    "(transport does not support notifiers)");
         return;
     }
@@ -164,11 +142,8 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
     /* If dataplane is (re-)enabled while the guest is running there could be
      * block jobs that can conflict.
      */
-    if (blk_op_is_blocked(conf->conf.blk, BLOCK_OP_TYPE_DATAPLANE,
-                          &local_err)) {
-        error_setg(errp, "cannot start dataplane thread: %s",
-                   error_get_pretty(local_err));
-        error_free(local_err);
+    if (blk_op_is_blocked(conf->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
+        error_prepend(errp, "cannot start dataplane thread: ");
         return;
     }
 
@@ -179,36 +154,16 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
     if (conf->iothread) {
         s->iothread = conf->iothread;
         object_ref(OBJECT(s->iothread));
-    } else {
-        /* Create per-device IOThread if none specified.  This is for
-         * x-data-plane option compatibility.  If x-data-plane is removed we
-         * can drop this.
-         */
-        object_initialize(&s->internal_iothread_obj,
-                          sizeof(s->internal_iothread_obj),
-                          TYPE_IOTHREAD);
-        user_creatable_complete(OBJECT(&s->internal_iothread_obj), &error_abort);
-        s->iothread = &s->internal_iothread_obj;
     }
     s->ctx = iothread_get_aio_context(s->iothread);
     s->bh = aio_bh_new(s->ctx, notify_guest_bh, s);
 
-    error_setg(&s->blocker, "block device is in use by data plane");
-    blk_op_block_all(conf->conf.blk, s->blocker);
-    blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_RESIZE, s->blocker);
-    blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_DRIVE_DEL, s->blocker);
-    blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_BACKUP_SOURCE, s->blocker);
-    blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_CHANGE, s->blocker);
-    blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_COMMIT_SOURCE, s->blocker);
-    blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_COMMIT_TARGET, s->blocker);
-    blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_EJECT, s->blocker);
-    blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_EXTERNAL_SNAPSHOT, s->blocker);
-    blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT, s->blocker);
-    blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
-                   s->blocker);
-    blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_MIRROR, s->blocker);
-    blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_STREAM, s->blocker);
-    blk_op_unblock(conf->conf.blk, BLOCK_OP_TYPE_REPLACE, s->blocker);
+    s->insert_notifier.notify = data_plane_blk_insert_notifier;
+    s->remove_notifier.notify = data_plane_blk_remove_notifier;
+    blk_add_insert_bs_notifier(conf->conf.blk, &s->insert_notifier);
+    blk_add_remove_bs_notifier(conf->conf.blk, &s->remove_notifier);
+
+    data_plane_set_up_op_blockers(s);
 
     *dataplane = s;
 }
@@ -221,36 +176,39 @@ void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s)
     }
 
     virtio_blk_data_plane_stop(s);
-    blk_op_unblock_all(s->conf->conf.blk, s->blocker);
-    error_free(s->blocker);
+    data_plane_remove_op_blockers(s);
+    notifier_remove(&s->insert_notifier);
+    notifier_remove(&s->remove_notifier);
     qemu_bh_delete(s->bh);
     object_unref(OBJECT(s->iothread));
     g_free(s);
 }
 
+static void virtio_blk_data_plane_handle_output(VirtIODevice *vdev,
+                                                VirtQueue *vq)
+{
+    VirtIOBlock *s = (VirtIOBlock *)vdev;
+
+    assert(s->dataplane);
+    assert(s->dataplane_started);
+
+    virtio_blk_handle_vq(s, vq);
+}
+
 /* Context: QEMU global mutex held */
 void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
 {
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
-    VirtQueue *vq;
     int r;
 
-    if (s->started || s->disabled) {
-        return;
-    }
-
-    if (s->starting) {
+    if (vblk->dataplane_started || s->starting) {
         return;
     }
 
     s->starting = true;
-
-    vq = virtio_get_queue(s->vdev, 0);
-    if (!vring_setup(&s->vring, s->vdev, 0)) {
-        goto fail_vring;
-    }
+    s->vq = virtio_get_queue(s->vdev, 0);
 
     /* Set up guest notifier (irq) */
     r = k->set_guest_notifiers(qbus->parent, 1, true);
@@ -259,7 +217,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
                 "ensure -enable-kvm is set\n", r);
         goto fail_guest_notifiers;
     }
-    s->guest_notifier = virtio_queue_get_guest_notifier(vq);
+    s->guest_notifier = virtio_queue_get_guest_notifier(s->vq);
 
     /* Set up virtqueue notify */
     r = k->set_host_notifier(qbus->parent, 0, true);
@@ -267,33 +225,29 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
         fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r);
         goto fail_host_notifier;
     }
-    s->host_notifier = *virtio_queue_get_host_notifier(vq);
-
-    s->saved_complete_request = vblk->complete_request;
-    vblk->complete_request = complete_request_vring;
 
     s->starting = false;
-    s->started = true;
+    vblk->dataplane_started = true;
     trace_virtio_blk_data_plane_start(s);
 
     blk_set_aio_context(s->conf->conf.blk, s->ctx);
 
     /* Kick right away to begin processing requests already in vring */
-    event_notifier_set(virtio_queue_get_host_notifier(vq));
+    event_notifier_set(virtio_queue_get_host_notifier(s->vq));
 
     /* Get this show started by hooking up our callbacks */
     aio_context_acquire(s->ctx);
-    aio_set_event_notifier(s->ctx, &s->host_notifier, handle_notify);
+    virtio_queue_aio_set_host_notifier_handler(s->vq, s->ctx,
+                                               virtio_blk_data_plane_handle_output);
     aio_context_release(s->ctx);
     return;
 
   fail_host_notifier:
     k->set_guest_notifiers(qbus->parent, 1, false);
   fail_guest_notifiers:
-    vring_teardown(&s->vring, s->vdev, 0);
-    s->disabled = true;
-  fail_vring:
+    vblk->dataplane_disabled = true;
     s->starting = false;
+    vblk->dataplane_started = true;
 }
 
 /* Context: QEMU global mutex held */
@@ -303,39 +257,34 @@ void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
 
-
-    /* Better luck next time. */
-    if (s->disabled) {
-        s->disabled = false;
+    if (!vblk->dataplane_started || s->stopping) {
         return;
     }
-    if (!s->started || s->stopping) {
+
+    /* Better luck next time. */
+    if (vblk->dataplane_disabled) {
+        vblk->dataplane_disabled = false;
+        vblk->dataplane_started = false;
         return;
     }
     s->stopping = true;
-    vblk->complete_request = s->saved_complete_request;
     trace_virtio_blk_data_plane_stop(s);
 
     aio_context_acquire(s->ctx);
 
     /* Stop notifications for new requests from guest */
-    aio_set_event_notifier(s->ctx, &s->host_notifier, NULL);
+    virtio_queue_aio_set_host_notifier_handler(s->vq, s->ctx, NULL);
 
     /* Drain and switch bs back to the QEMU main loop */
     blk_set_aio_context(s->conf->conf.blk, qemu_get_aio_context());
 
     aio_context_release(s->ctx);
 
-    /* Sync vring state back to virtqueue so that non-dataplane request
-     * processing can continue when we disable the host notifier below.
-     */
-    vring_teardown(&s->vring, s->vdev, 0);
-
     k->set_host_notifier(qbus->parent, 0, false);
 
     /* Clean up guest notifier (irq) */
     k->set_guest_notifiers(qbus->parent, 1, false);
 
-    s->started = false;
+    vblk->dataplane_started = false;
     s->stopping = false;
 }
diff --git a/qemu/hw/block/dataplane/virtio-blk.h b/qemu/hw/block/dataplane/virtio-blk.h
index c88d40e72..0714c11a2 100644
--- a/qemu/hw/block/dataplane/virtio-blk.h
+++ b/qemu/hw/block/dataplane/virtio-blk.h
@@ -26,5 +26,6 @@ void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s);
 void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s);
 void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s);
 void virtio_blk_data_plane_drain(VirtIOBlockDataPlane *s);
+void virtio_blk_data_plane_notify(VirtIOBlockDataPlane *s);
 
 #endif /* HW_DATAPLANE_VIRTIO_BLK_H */