From 51b04ac5c6a63cc8cd477c15a7e0998e0af24bcc Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 21 Jun 2016 13:13:15 +0100 Subject: [PATCH] virtio-blk: dataplane multiqueue support Monitor ioeventfds for all virtqueues in the device's AioContext. This is not true multiqueue because requests from all virtqueues are processed in a single IOThread. In the future it will be possible to use multiple IOThreads when the QEMU block layer supports multiqueue. Signed-off-by: Stefan Hajnoczi Reviewed-by: Fam Zheng Message-id: 1466511196-12612-7-git-send-email-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi --- hw/block/dataplane/virtio-blk.c | 50 ++++++++++++++++++++++++++++------------- 1 file changed, 34 insertions(+), 16 deletions(-) diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c index 835021b235..54b9ac1da6 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -31,9 +31,7 @@ struct VirtIOBlockDataPlane { bool stopping; VirtIOBlkConf *conf; - VirtIODevice *vdev; - VirtQueue *vq; /* virtqueue vring */ QEMUBH *bh; /* bh for guest notification */ unsigned long *batch_notify_vqs; @@ -156,6 +154,8 @@ 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); + unsigned i; + unsigned nvqs = s->conf->num_queues; int r; if (vblk->dataplane_started || s->starting) { @@ -163,10 +163,9 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s) } s->starting = true; - s->vq = virtio_get_queue(s->vdev, 0); /* Set up guest notifier (irq) */ - r = k->set_guest_notifiers(qbus->parent, 1, true); + r = k->set_guest_notifiers(qbus->parent, nvqs, true); if (r != 0) { fprintf(stderr, "virtio-blk failed to set guest notifier (%d), " "ensure -enable-kvm is set\n", r); @@ -174,10 +173,15 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s) } /* Set up virtqueue notify */ - r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), 0, true); - if (r != 0) { - fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r); - goto fail_host_notifier; + for (i = 0; i < nvqs; i++) { + r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, true); + if (r != 0) { + fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r); + while (i--) { + virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); + } + goto fail_guest_notifiers; + } } s->starting = false; @@ -187,17 +191,23 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *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(s->vq)); + for (i = 0; i < nvqs; i++) { + VirtQueue *vq = virtio_get_queue(s->vdev, i); + + event_notifier_set(virtio_queue_get_host_notifier(vq)); + } /* Get this show started by hooking up our callbacks */ aio_context_acquire(s->ctx); - virtio_queue_aio_set_host_notifier_handler(s->vq, s->ctx, - virtio_blk_data_plane_handle_output); + for (i = 0; i < nvqs; i++) { + VirtQueue *vq = virtio_get_queue(s->vdev, i); + + virtio_queue_aio_set_host_notifier_handler(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: vblk->dataplane_disabled = true; s->starting = false; @@ -210,6 +220,8 @@ void virtio_blk_data_plane_stop(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); + unsigned i; + unsigned nvqs = s->conf->num_queues; if (!vblk->dataplane_started || s->stopping) { return; @@ -227,17 +239,23 @@ void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s) aio_context_acquire(s->ctx); /* Stop notifications for new requests from guest */ - virtio_queue_aio_set_host_notifier_handler(s->vq, s->ctx, NULL); + for (i = 0; i < nvqs; i++) { + VirtQueue *vq = virtio_get_queue(s->vdev, i); + + virtio_queue_aio_set_host_notifier_handler(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); - virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), 0, false); + for (i = 0; i < nvqs; i++) { + virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); + } /* Clean up guest notifier (irq) */ - k->set_guest_notifiers(qbus->parent, 1, false); + k->set_guest_notifiers(qbus->parent, nvqs, false); vblk->dataplane_started = false; s->stopping = false; -- 2.11.4.GIT