*
*/
+#include "qemu/osdep.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 "block/block.h"
+#include "hw/virtio/dataplane/vring-accessors.h"
+#include "sysemu/block-backend.h"
#include "hw/virtio/virtio-blk.h"
#include "virtio-blk.h"
#include "block/aio.h"
bool started;
bool starting;
bool stopping;
+ bool disabled;
- VirtIOBlkConf *blk;
+ VirtIOBlkConf *conf;
VirtIODevice *vdev;
Vring vring; /* virtqueue vring */
EventNotifier *guest_notifier; /* irq */
+ QEMUBH *bh; /* bh for guest notification */
/* Note that these EventNotifiers are assigned by value. This is
* fine as long as you do not call event_notifier_cleanup on them
* use it).
*/
IOThread *iothread;
- IOThread internal_iothread_obj;
AioContext *ctx;
EventNotifier host_notifier; /* doorbell */
event_notifier_set(s->guest_notifier);
}
+static void notify_guest_bh(void *opaque)
+{
+ VirtIOBlockDataPlane *s = opaque;
+
+ notify_guest(s);
+}
+
static void complete_request_vring(VirtIOBlockReq *req, unsigned char status)
{
+ VirtIOBlockDataPlane *s = req->dev->dataplane;
stb_p(&req->in->status, status);
- vring_push(&req->dev->dataplane->vring, req->elem,
- req->qiov.size + sizeof(*req->in));
- notify_guest(req->dev->dataplane);
+ vring_push(s->vdev, &req->dev->dataplane->vring, &req->elem, req->in_len);
+
+ /* 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 handle_notify(EventNotifier *e)
{
VirtIOBlockDataPlane *s = container_of(e, VirtIOBlockDataPlane,
host_notifier);
-
- VirtQueueElement *elem;
- VirtIOBlockReq *req;
- int ret;
- MultiReqBuffer mrb = {
- .num_writes = 0,
- };
+ VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
event_notifier_test_and_clear(&s->host_notifier);
- bdrv_io_plug(s->blk->conf.bs);
+ 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 (;;) {
- ret = vring_pop(s->vdev, &s->vring, &elem);
+ VirtIOBlockReq *req = virtio_blk_alloc_request(vblk);
+
+ ret = vring_pop(s->vdev, &s->vring, &req->elem);
if (ret < 0) {
- assert(elem == NULL);
+ virtio_blk_free_request(req);
break; /* no more requests */
}
- trace_virtio_blk_data_plane_process_request(s, elem->out_num,
- elem->in_num, elem->index);
+ trace_virtio_blk_data_plane_process_request(s, req->elem.out_num,
+ req->elem.in_num,
+ req->elem.index);
- req = g_slice_new(VirtIOBlockReq);
- req->dev = VIRTIO_BLK(s->vdev);
- req->elem = elem;
virtio_blk_handle_request(req, &mrb);
}
- virtio_submit_multiwrite(s->blk->conf.bs, &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.
break;
}
}
- bdrv_io_unplug(s->blk->conf.bs);
+ blk_io_unplug(s->conf->conf.blk);
}
/* Context: QEMU global mutex held */
-void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *blk,
+void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
VirtIOBlockDataPlane **dataplane,
Error **errp)
{
VirtIOBlockDataPlane *s;
- VirtIOBlock *vblk = VIRTIO_BLK(vdev);
- Error *local_err = NULL;
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
*dataplane = NULL;
- if (!blk->data_plane && !blk->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;
}
/* If dataplane is (re-)enabled while the guest is running there could be
* block jobs that can conflict.
*/
- if (bdrv_op_is_blocked(blk->conf.bs, BLOCK_OP_TYPE_DATAPLANE, &local_err)) {
- error_report("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;
}
s = g_new0(VirtIOBlockDataPlane, 1);
s->vdev = vdev;
- s->blk = blk;
+ s->conf = conf;
- if (blk->iothread) {
- s->iothread = blk->iothread;
+ 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");
- bdrv_op_block_all(blk->conf.bs, s->blocker);
+ 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_SOURCE, 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);
*dataplane = s;
- s->saved_complete_request = vblk->complete_request;
- vblk->complete_request = complete_request_vring;
}
/* Context: QEMU global mutex held */
}
virtio_blk_data_plane_stop(s);
- bdrv_op_unblock_all(s->blk->conf.bs, s->blocker);
+ blk_op_unblock_all(s->conf->conf.blk, s->blocker);
error_free(s->blocker);
+ qemu_bh_delete(s->bh);
object_unref(OBJECT(s->iothread));
g_free(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) {
+ if (s->started || s->disabled) {
return;
}
vq = virtio_get_queue(s->vdev, 0);
if (!vring_setup(&s->vring, s->vdev, 0)) {
- s->starting = false;
- return;
+ goto fail_vring;
}
/* Set up guest notifier (irq) */
- if (k->set_guest_notifiers(qbus->parent, 1, true) != 0) {
- fprintf(stderr, "virtio-blk failed to set guest notifier, "
- "ensure -enable-kvm is set\n");
- exit(1);
+ r = k->set_guest_notifiers(qbus->parent, 1, true);
+ if (r != 0) {
+ fprintf(stderr, "virtio-blk failed to set guest notifier (%d), "
+ "ensure -enable-kvm is set\n", r);
+ goto fail_guest_notifiers;
}
s->guest_notifier = virtio_queue_get_guest_notifier(vq);
/* Set up virtqueue notify */
- if (k->set_host_notifier(qbus->parent, 0, true) != 0) {
- fprintf(stderr, "virtio-blk failed to set host notifier\n");
- exit(1);
+ r = k->set_host_notifier(qbus->parent, 0, true);
+ if (r != 0) {
+ 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;
trace_virtio_blk_data_plane_start(s);
- bdrv_set_aio_context(s->blk->conf.bs, s->ctx);
+ 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));
/* 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);
+ aio_set_event_notifier(s->ctx, &s->host_notifier, true,
+ handle_notify);
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:
+ s->starting = false;
}
/* Context: QEMU global mutex held */
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
+
+
+ /* Better luck next time. */
+ if (s->disabled) {
+ s->disabled = false;
+ return;
+ }
if (!s->started || s->stopping) {
return;
}
aio_context_acquire(s->ctx);
/* Stop notifications for new requests from guest */
- aio_set_event_notifier(s->ctx, &s->host_notifier, NULL);
+ aio_set_event_notifier(s->ctx, &s->host_notifier, true, NULL);
/* Drain and switch bs back to the QEMU main loop */
- bdrv_set_aio_context(s->blk->conf.bs, qemu_get_aio_context());
+ blk_set_aio_context(s->conf->conf.blk, qemu_get_aio_context());
aio_context_release(s->ctx);
projects / qemu.git / blobdiff