On 01/25/2013 06:35 PM, Jason Wang wrote: > This patch lets vhost support multiqueue. The idea is simple, just launching > multiple threads of vhost and let each of vhost thread processing a subset of > the virtqueues of the device. After this change each emulated device can have > multiple vhost threads as its backend. > > To do this, a virtqueue index were introduced to record to first virtqueue > that > will be handled by this vhost_net device. Based on this and nvqs, vhost could > calculate its relative index to setup vhost_net device. > > Since we may have many vhost/net devices for a virtio-net device. The setting > of > guest notifiers were moved out of the starting/stopping of a specific vhost > thread. The vhost_net_{start|stop}() were renamed to > vhost_net_{start|stop}_one(), and a new vhost_net_{start|stop}() were > introduced > to configure the guest notifiers and start/stop all vhost/vhost_net devices. > > Signed-off-by: Jason Wang <jasow...@redhat.com> > --- > hw/vhost.c | 82 +++++++++++++++++++++--------------------------- > hw/vhost.h | 2 + > hw/vhost_net.c | 92 > ++++++++++++++++++++++++++++++++++++++++++++++++++----- > hw/vhost_net.h | 6 ++- > hw/virtio-net.c | 4 +- > 5 files changed, 128 insertions(+), 58 deletions(-) > > diff --git a/hw/vhost.c b/hw/vhost.c > index cee8aad..38257b9 100644 > --- a/hw/vhost.c > +++ b/hw/vhost.c > @@ -619,14 +619,17 @@ static int vhost_virtqueue_start(struct vhost_dev *dev, > { > hwaddr s, l, a; > int r; > + int vhost_vq_index = idx - dev->vq_index; > struct vhost_vring_file file = { > - .index = idx, > + .index = vhost_vq_index > }; > struct vhost_vring_state state = { > - .index = idx, > + .index = vhost_vq_index > }; > struct VirtQueue *vvq = virtio_get_queue(vdev, idx); > > + assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs); > + > vq->num = state.num = virtio_queue_get_num(vdev, idx); > r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state); > if (r) { > @@ -669,11 +672,12 @@ static int vhost_virtqueue_start(struct vhost_dev *dev, > goto fail_alloc_ring; > } > > - r = vhost_virtqueue_set_addr(dev, vq, idx, dev->log_enabled); > + r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled); > if (r < 0) { > r = -errno; > goto fail_alloc; > } > + > file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); > r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file); > if (r) { > @@ -709,9 +713,10 @@ static void vhost_virtqueue_stop(struct vhost_dev *dev, > unsigned idx) > { > struct vhost_vring_state state = { > - .index = idx, > + .index = idx - dev->vq_index > }; > int r; > + assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs); > r = ioctl(dev->control, VHOST_GET_VRING_BASE, &state); > if (r < 0) { > fprintf(stderr, "vhost VQ %d ring restore failed: %d\n", idx, r); > @@ -867,7 +872,9 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, > VirtIODevice *vdev) > } > > for (i = 0; i < hdev->nvqs; ++i) { > - r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, true); > + r = vdev->binding->set_host_notifier(vdev->binding_opaque, > + hdev->vq_index + i, > + true); > if (r < 0) { > fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, > -r); > goto fail_vq; > @@ -877,7 +884,9 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, > VirtIODevice *vdev) > return 0; > fail_vq: > while (--i >= 0) { > - r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false); > + r = vdev->binding->set_host_notifier(vdev->binding_opaque, > + hdev->vq_index + i, > + false); > if (r < 0) { > fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, > -r); > fflush(stderr); > @@ -898,7 +907,9 @@ void vhost_dev_disable_notifiers(struct vhost_dev *hdev, > VirtIODevice *vdev) > int i, r; > > for (i = 0; i < hdev->nvqs; ++i) { > - r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false); > + r = vdev->binding->set_host_notifier(vdev->binding_opaque, > + hdev->vq_index + i, > + false); > if (r < 0) { > fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, > -r); > fflush(stderr); > @@ -912,8 +923,9 @@ void vhost_dev_disable_notifiers(struct vhost_dev *hdev, > VirtIODevice *vdev) > */ > bool vhost_virtqueue_pending(struct vhost_dev *hdev, int n) > { > - struct vhost_virtqueue *vq = hdev->vqs + n; > + struct vhost_virtqueue *vq = hdev->vqs + n - hdev->vq_index; > assert(hdev->started); > + assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); > return event_notifier_test_and_clear(&vq->masked_notifier); > } > > @@ -922,15 +934,16 @@ void vhost_virtqueue_mask(struct vhost_dev *hdev, > VirtIODevice *vdev, int n, > bool mask) > { > struct VirtQueue *vvq = virtio_get_queue(vdev, n); > - int r; > + int r, index = n - hdev->vq_index; > > assert(hdev->started); > + assert(n >= hdev->vq_index && n < hdev->vq_index + hdev->nvqs); > > struct vhost_vring_file file = { > - .index = n, > + .index = index > }; > if (mask) { > - file.fd = event_notifier_get_fd(&hdev->vqs[n].masked_notifier); > + file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); > } else { > file.fd = > event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); > } > @@ -945,20 +958,6 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice > *vdev) > > hdev->started = true; > > - if (!vdev->binding->set_guest_notifiers) { > - fprintf(stderr, "binding does not support guest notifiers\n"); > - r = -ENOSYS; > - goto fail; > - } > - > - r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, > - hdev->nvqs, > - true); > - if (r < 0) { > - fprintf(stderr, "Error binding guest notifier: %d\n", -r); > - goto fail_notifiers; > - } > - > r = vhost_dev_set_features(hdev, hdev->log_enabled); > if (r < 0) { > goto fail_features; > @@ -970,9 +969,9 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice > *vdev) > } > for (i = 0; i < hdev->nvqs; ++i) { > r = vhost_virtqueue_start(hdev, > - vdev, > - hdev->vqs + i, > - i); > + vdev, > + hdev->vqs + i, > + hdev->vq_index + i); > if (r < 0) { > goto fail_vq; > } > @@ -995,15 +994,13 @@ fail_log: > fail_vq: > while (--i >= 0) { > vhost_virtqueue_stop(hdev, > - vdev, > - hdev->vqs + i, > - i); > + vdev, > + hdev->vqs + i, > + hdev->vq_index + i); > } > + i = hdev->nvqs; > fail_mem: > fail_features: > - vdev->binding->set_guest_notifiers(vdev->binding_opaque, hdev->nvqs, > false); > -fail_notifiers: > -fail: > > hdev->started = false; > return r; > @@ -1012,29 +1009,22 @@ fail: > /* Host notifiers must be enabled at this point. */ > void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev) > { > - int i, r; > + int i; > > for (i = 0; i < hdev->nvqs; ++i) { > vhost_virtqueue_stop(hdev, > - vdev, > - hdev->vqs + i, > - i); > + vdev, > + hdev->vqs + i, > + hdev->vq_index + i); > } > for (i = 0; i < hdev->n_mem_sections; ++i) { > vhost_sync_dirty_bitmap(hdev, &hdev->mem_sections[i], > 0, (hwaddr)~0x0ull); > } > - r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, > - hdev->nvqs, > - false); > - if (r < 0) { > - fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r); > - fflush(stderr); > - } > - assert (r >= 0); > > hdev->started = false; > g_free(hdev->log); > hdev->log = NULL; > hdev->log_size = 0; > } > + > diff --git a/hw/vhost.h b/hw/vhost.h > index 44c61a5..f062d48 100644 > --- a/hw/vhost.h > +++ b/hw/vhost.h > @@ -35,6 +35,8 @@ struct vhost_dev { > MemoryRegionSection *mem_sections; > struct vhost_virtqueue *vqs; > int nvqs; > + /* the first virtuque which would be used by this vhost dev */ > + int vq_index; > unsigned long long features; > unsigned long long acked_features; > unsigned long long backend_features; > diff --git a/hw/vhost_net.c b/hw/vhost_net.c > index d3a04ca..c955611 100644 > --- a/hw/vhost_net.c > +++ b/hw/vhost_net.c > @@ -140,12 +140,21 @@ bool vhost_net_query(VHostNetState *net, VirtIODevice > *dev) > return vhost_dev_query(&net->dev, dev); > } > > -int vhost_net_start(struct vhost_net *net, > - VirtIODevice *dev) > +static int vhost_net_start_one(struct vhost_net *net, > + VirtIODevice *dev, > + int vq_index) > { > struct vhost_vring_file file = { }; > int r; > > + if (net->dev.started) { > + return 0; > + } > + > + net->dev.nvqs = 2; > + net->dev.vqs = net->vqs; > + net->dev.vq_index = vq_index; > + > r = vhost_dev_enable_notifiers(&net->dev, dev); > if (r < 0) { > goto fail_notifiers; > @@ -181,11 +190,15 @@ fail_notifiers: > return r; > } > > -void vhost_net_stop(struct vhost_net *net, > - VirtIODevice *dev) > +static void vhost_net_stop_one(struct vhost_net *net, > + VirtIODevice *dev) > { > struct vhost_vring_file file = { .fd = -1 }; > > + if (!net->dev.started) { > + return; > + } > + > for (file.index = 0; file.index < net->dev.nvqs; ++file.index) { > int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file); > assert(r >= 0); > @@ -195,6 +208,65 @@ void vhost_net_stop(struct vhost_net *net, > vhost_dev_disable_notifiers(&net->dev, dev); > } > > +int vhost_net_start(VirtIODevice *dev, NetClientState *ncs, > + int start_queues, int total_queues) > +{ > + int r, i = 0; > + > + if (!dev->binding->set_guest_notifiers) { > + error_report("binding does not support guest notifiers\n"); > + r = -ENOSYS; > + goto err; > + } > + > + for (i = start_queues; i < total_queues; i++) { > + vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev); > + } > +
Since kernel will support polling/writing when detached, there's no need to stop the vhost threads that is polling the disabled queue here. This can further simplify the interface between virtio-net and vhost. Will send a new version. > + for (i = 0; i < start_queues; i++) { > + r = vhost_net_start_one(tap_get_vhost_net(ncs[i].peer), dev, i * 2); > + > + if (r < 0) { > + goto err; > + } > + } > + > + r = dev->binding->set_guest_notifiers(dev->binding_opaque, > + start_queues * 2, > + true); > + if (r < 0) { > + error_report("Error binding guest notifier: %d\n", -r); > + goto err; > + } > + > + return 0; > + > +err: > + while (--i >= 0) { > + vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev); > + } > + return r; > +} > + > +void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs, > + int start_queues, int total_queues) > +{ > + int i, r; > + > + r = dev->binding->set_guest_notifiers(dev->binding_opaque, > + start_queues * 2, > + false); > + if (r < 0) { > + fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r); > + fflush(stderr); > + } > + assert(r >= 0); > + > + for (i = 0; i < total_queues; i++) { > + vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev); > + } > +} > + > void vhost_net_cleanup(struct vhost_net *net) > { > vhost_dev_cleanup(&net->dev); > @@ -224,13 +296,17 @@ bool vhost_net_query(VHostNetState *net, VirtIODevice > *dev) > return false; > } > > -int vhost_net_start(struct vhost_net *net, > - VirtIODevice *dev) > +int vhost_net_start(VirtIODevice *dev, > + NetClientState *ncs, > + int start_queues, > + int total_queues) > { > return -ENOSYS; > } > -void vhost_net_stop(struct vhost_net *net, > - VirtIODevice *dev) > +void vhost_net_stop(VirtIODevice *dev, > + NetClientState *ncs, > + int start_queues, > + int total_queues) > { > } > > diff --git a/hw/vhost_net.h b/hw/vhost_net.h > index 88912b8..9fbd79d 100644 > --- a/hw/vhost_net.h > +++ b/hw/vhost_net.h > @@ -9,8 +9,10 @@ typedef struct vhost_net VHostNetState; > VHostNetState *vhost_net_init(NetClientState *backend, int devfd, bool > force); > > bool vhost_net_query(VHostNetState *net, VirtIODevice *dev); > -int vhost_net_start(VHostNetState *net, VirtIODevice *dev); > -void vhost_net_stop(VHostNetState *net, VirtIODevice *dev); > +int vhost_net_start(VirtIODevice *dev, NetClientState *ncs, > + int start_queues, int total_queues); > +void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs, > + int start_queues, int total_queues); > > void vhost_net_cleanup(VHostNetState *net); > > diff --git a/hw/virtio-net.c b/hw/virtio-net.c > index 47f4ab4..2f49fd8 100644 > --- a/hw/virtio-net.c > +++ b/hw/virtio-net.c > @@ -129,14 +129,14 @@ static void virtio_net_vhost_status(VirtIONet *n, > uint8_t status) > return; > } > n->vhost_started = 1; > - r = vhost_net_start(tap_get_vhost_net(nc->peer), &n->vdev); > + r = vhost_net_start(&n->vdev, nc, 1, 1); > if (r < 0) { > error_report("unable to start vhost net: %d: " > "falling back on userspace virtio", -r); > n->vhost_started = 0; > } > } else { > - vhost_net_stop(tap_get_vhost_net(nc->peer), &n->vdev); > + vhost_net_stop(&n->vdev, nc, 1, 1); > n->vhost_started = 0; > } > } -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html