int virtio_bus_start_ioeventfd(VirtioBusState *bus)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
int r;
if (!k->ioeventfd_assign || !k->ioeventfd_enabled(proxy)) {
return -ENOSYS;
}
if (bus->ioeventfd_started) {
return 0;
}
/* Only set our notifier if we have ownership. */
if (!bus->ioeventfd_grabbed) {
r = vdc->start_ioeventfd(vdev);
if (r < 0) {
error_report("%s: failed. Fallback to userspace (slower).", __func__);
return r;
}
}
bus->ioeventfd_started = true;
return 0;
}
/* Plug the VirtIODevice */
int virtio_bus_plug_device(VirtIODevice *vdev)
{
DeviceState *qdev = DEVICE(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(qdev));
VirtioBusState *bus = VIRTIO_BUS(qbus);
VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
DPRINTF("%s: plug device.\n", qbus->name);
bus->vdev = vdev;
/*
* The lines below will disappear when we drop VirtIOBindings, at the end
* of the series.
*/
bus->bindings.notify = klass->notify;
bus->bindings.save_config = klass->save_config;
bus->bindings.save_queue = klass->save_queue;
bus->bindings.load_config = klass->load_config;
bus->bindings.load_queue = klass->load_queue;
bus->bindings.load_done = klass->load_done;
bus->bindings.get_features = klass->get_features;
bus->bindings.query_guest_notifiers = klass->query_guest_notifiers;
bus->bindings.set_guest_notifiers = klass->set_guest_notifiers;
bus->bindings.set_host_notifier = klass->set_host_notifier;
bus->bindings.vmstate_change = klass->vmstate_change;
virtio_bind_device(bus->vdev, &bus->bindings, qbus->parent);
if (klass->device_plugged != NULL) {
klass->device_plugged(qbus->parent);
}
return 0;
}
/* Context: QEMU global mutex held */
void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
VirtIOBlockDataPlane **dataplane,
Error **errp)
{
VirtIOBlockDataPlane *s;
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
*dataplane = NULL;
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 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 (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->conf = conf;
if (conf->iothread) {
s->iothread = conf->iothread;
object_ref(OBJECT(s->iothread));
}
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_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;
}
bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
return k->ioeventfd_assign && k->ioeventfd_enabled(proxy);
}
/*
* This function handles both assigning the ioeventfd handler and
* registering it with the kernel.
* assign: register/deregister ioeventfd with the kernel
* set_handler: use the generic ioeventfd handler
*/
static int set_host_notifier_internal(DeviceState *proxy, VirtioBusState *bus,
int n, bool assign, bool set_handler)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
VirtQueue *vq = virtio_get_queue(vdev, n);
EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
int r = 0;
if (assign) {
r = event_notifier_init(notifier, 1);
if (r < 0) {
error_report("%s: unable to init event notifier: %d", __func__, r);
return r;
}
virtio_queue_set_host_notifier_fd_handler(vq, true, set_handler);
r = k->ioeventfd_assign(proxy, notifier, n, assign);
if (r < 0) {
error_report("%s: unable to assign ioeventfd: %d", __func__, r);
virtio_queue_set_host_notifier_fd_handler(vq, false, false);
event_notifier_cleanup(notifier);
return r;
}
} else {
k->ioeventfd_assign(proxy, notifier, n, assign);
virtio_queue_set_host_notifier_fd_handler(vq, false, false);
event_notifier_cleanup(notifier);
}
return r;
}
static void vhost_vsock_stop(VirtIODevice *vdev)
{
VHostVSock *vsock = VHOST_VSOCK(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
int ret;
if (!k->set_guest_notifiers) {
return;
}
ret = vhost_vsock_set_running(vsock, 0);
if (ret < 0) {
error_report("vhost vsock set running failed: %d", ret);
return;
}
vhost_dev_stop(&vsock->vhost_dev, vdev);
ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false);
if (ret < 0) {
error_report("vhost guest notifier cleanup failed: %d", ret);
return;
}
vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev);
}
/* Context: QEMU global mutex held */
void virtio_scsi_dataplane_start(VirtIOSCSI *s)
{
int i;
int rc;
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
if (s->dataplane_started ||
s->dataplane_starting ||
s->dataplane_fenced ||
s->ctx != iothread_get_aio_context(vs->conf.iothread)) {
return;
}
s->dataplane_starting = true;
/* Set up guest notifier (irq) */
rc = k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, true);
if (rc != 0) {
fprintf(stderr, "virtio-scsi: Failed to set guest notifiers (%d), "
"ensure -enable-kvm is set\n", rc);
goto fail_guest_notifiers;
}
aio_context_acquire(s->ctx);
rc = virtio_scsi_vring_init(s, vs->ctrl_vq, 0);
if (rc) {
goto fail_vrings;
}
rc = virtio_scsi_vring_init(s, vs->event_vq, 1);
if (rc) {
goto fail_vrings;
}
for (i = 0; i < vs->conf.num_queues; i++) {
rc = virtio_scsi_vring_init(s, vs->cmd_vqs[i], i + 2);
if (rc) {
goto fail_vrings;
}
}
s->dataplane_starting = false;
s->dataplane_started = true;
aio_context_release(s->ctx);
return;
fail_vrings:
virtio_scsi_clear_aio(s);
aio_context_release(s->ctx);
for (i = 0; i < vs->conf.num_queues + 2; i++) {
k->set_host_notifier(qbus->parent, i, false);
}
k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
fail_guest_notifiers:
s->dataplane_fenced = true;
s->dataplane_starting = false;
s->dataplane_started = true;
}
static void vhost_vsock_start(VirtIODevice *vdev)
{
VHostVSock *vsock = VHOST_VSOCK(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
int ret;
int i;
if (!k->set_guest_notifiers) {
error_report("binding does not support guest notifiers");
return;
}
ret = vhost_dev_enable_notifiers(&vsock->vhost_dev, vdev);
if (ret < 0) {
error_report("Error enabling host notifiers: %d", -ret);
return;
}
ret = k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, true);
if (ret < 0) {
error_report("Error binding guest notifier: %d", -ret);
goto err_host_notifiers;
}
vsock->vhost_dev.acked_features = vdev->guest_features;
ret = vhost_dev_start(&vsock->vhost_dev, vdev);
if (ret < 0) {
error_report("Error starting vhost: %d", -ret);
goto err_guest_notifiers;
}
ret = vhost_vsock_set_running(vsock, 1);
if (ret < 0) {
error_report("Error starting vhost vsock: %d", -ret);
goto err_dev_start;
}
/* guest_notifier_mask/pending not used yet, so just unmask
* everything here. virtio-pci will do the right thing by
* enabling/disabling irqfd.
*/
for (i = 0; i < vsock->vhost_dev.nvqs; i++) {
vhost_virtqueue_mask(&vsock->vhost_dev, vdev, i, false);
}
return;
err_dev_start:
vhost_dev_stop(&vsock->vhost_dev, vdev);
err_guest_notifiers:
k->set_guest_notifiers(qbus->parent, vsock->vhost_dev.nvqs, false);
err_host_notifiers:
vhost_dev_disable_notifiers(&vsock->vhost_dev, vdev);
}
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);
}
net->nc->info->poll(net->nc, true);
vhost_dev_stop(&net->dev, dev);
vhost_dev_disable_notifiers(&net->dev, dev);
}
int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
int total_queues)
{
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
VirtioBusState *vbus = VIRTIO_BUS(qbus);
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
int r, i = 0;
if (!k->set_guest_notifiers) {
error_report("binding does not support guest notifiers");
r = -ENOSYS;
goto err;
}
for (i = 0; i < total_queues; i++) {
r = vhost_net_start_one(tap_get_vhost_net(ncs[i].peer), dev, i * 2);
if (r < 0) {
goto err;
}
}
r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
if (r < 0) {
error_report("Error binding guest notifier: %d", -r);
goto err;
}
return 0;
err:
while (--i >= 0) {
vhost_net_stop_one(tap_get_vhost_net(ncs[i].peer), dev);
}
return r;
}
/* 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);
int r;
if (vblk->dataplane_started || s->starting) {
return;
}
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);
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(s->vq);
/* Set up virtqueue notify */
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->starting = false;
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(s->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);
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;
vblk->dataplane_started = true;
}
/* A VirtIODevice is being plugged */
int virtio_bus_device_plugged(VirtIODevice *vdev)
{
DeviceState *qdev = DEVICE(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(qdev));
VirtioBusState *bus = VIRTIO_BUS(qbus);
VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
DPRINTF("%s: plug device.\n", qbus->name);
if (klass->device_plugged != NULL) {
klass->device_plugged(qbus->parent);
}
return 0;
}
/* Context: QEMU global mutex held */
void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
VirtIOBlockDataPlane **dataplane,
Error **errp)
{
VirtIOBlockDataPlane *s;
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
*dataplane = NULL;
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 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 (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->conf = conf;
if (conf->iothread) {
s->iothread = conf->iothread;
object_ref(OBJECT(s->iothread));
}
s->ctx = iothread_get_aio_context(s->iothread);
s->bh = aio_bh_new(s->ctx, notify_guest_bh, s);
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;
}
/* A VirtIODevice is being unplugged */
void virtio_bus_device_unplugged(VirtIODevice *vdev)
{
DeviceState *qdev = DEVICE(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(qdev));
VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(qbus);
DPRINTF("%s: remove device.\n", qbus->name);
if (vdev != NULL) {
if (klass->device_unplugged != NULL) {
klass->device_unplugged(qbus->parent);
}
}
}
/* Context: QEMU global mutex held */
void virtio_scsi_set_iothread(VirtIOSCSI *s, IOThread *iothread)
{
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
assert(!s->ctx);
s->ctx = iothread_get_aio_context(vs->conf.iothread);
/* Don't try if transport does not support notifiers. */
if (!k->set_guest_notifiers || !k->set_host_notifier) {
fprintf(stderr, "virtio-scsi: Failed to set iothread "
"(transport does not support notifiers)");
exit(1);
}
}
/* Destroy the VirtIODevice */
void virtio_bus_destroy_device(VirtioBusState *bus)
{
DeviceState *qdev;
BusState *qbus = BUS(bus);
VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
DPRINTF("%s: remove device.\n", qbus->name);
if (bus->vdev != NULL) {
if (klass->device_unplug != NULL) {
klass->device_unplug(qbus->parent);
}
qdev = DEVICE(bus->vdev);
qdev_free(qdev);
bus->vdev = NULL;
}
}
int vhost_scsi_common_start(VHostSCSICommon *vsc)
{
int ret, i;
VirtIODevice *vdev = VIRTIO_DEVICE(vsc);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
if (!k->set_guest_notifiers) {
error_report("binding does not support guest notifiers");
return -ENOSYS;
}
ret = vhost_dev_enable_notifiers(&vsc->dev, vdev);
if (ret < 0) {
return ret;
}
ret = k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, true);
if (ret < 0) {
error_report("Error binding guest notifier");
goto err_host_notifiers;
}
vsc->dev.acked_features = vdev->guest_features;
ret = vhost_dev_start(&vsc->dev, vdev);
if (ret < 0) {
error_report("Error start vhost dev");
goto err_guest_notifiers;
}
/* guest_notifier_mask/pending not used yet, so just unmask
* everything here. virtio-pci will do the right thing by
* enabling/disabling irqfd.
*/
for (i = 0; i < vsc->dev.nvqs; i++) {
vhost_virtqueue_mask(&vsc->dev, vdev, vsc->dev.vq_index + i, false);
}
return ret;
err_guest_notifiers:
k->set_guest_notifiers(qbus->parent, vsc->dev.nvqs, false);
err_host_notifiers:
vhost_dev_disable_notifiers(&vsc->dev, vdev);
return ret;
}
/* Context: QEMU global mutex held */
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;
}
/* Better luck next time. */
if (vblk->dataplane_disabled) {
vblk->dataplane_disabled = false;
vblk->dataplane_started = false;
return;
}
s->stopping = true;
trace_virtio_blk_data_plane_stop(s);
aio_context_acquire(s->ctx);
/* Stop notifications for new requests from guest */
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);
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, nvqs, false);
vblk->dataplane_started = false;
s->stopping = false;
}
static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n)
{
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
int rc;
/* Set up virtqueue notify */
rc = k->set_host_notifier(qbus->parent, n, true);
if (rc != 0) {
fprintf(stderr, "virtio-scsi: Failed to set host notifier (%d)\n",
rc);
s->dataplane_fenced = true;
return rc;
}
virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, true, true);
return 0;
}
/* A VirtIODevice is being plugged */
void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp)
{
DeviceState *qdev = DEVICE(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(qdev));
VirtioBusState *bus = VIRTIO_BUS(qbus);
VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
bool has_iommu = virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
Error *local_err = NULL;
DPRINTF("%s: plug device.\n", qbus->name);
if (klass->pre_plugged != NULL) {
klass->pre_plugged(qbus->parent, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
}
/* Get the features of the plugged device. */
assert(vdc->get_features != NULL);
vdev->host_features = vdc->get_features(vdev, vdev->host_features,
&local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
if (klass->device_plugged != NULL) {
klass->device_plugged(qbus->parent, &local_err);
}
if (local_err) {
error_propagate(errp, local_err);
return;
}
if (klass->get_dma_as != NULL && has_iommu) {
virtio_add_feature(&vdev->host_features, VIRTIO_F_IOMMU_PLATFORM);
vdev->dma_as = klass->get_dma_as(qbus->parent);
} else {
vdev->dma_as = &address_space_memory;
}
}
void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
int total_queues)
{
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
VirtioBusState *vbus = VIRTIO_BUS(qbus);
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
int i, r;
for (i = 0; i < total_queues; i++) {
vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
}
r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
if (r < 0) {
fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
fflush(stderr);
}
assert(r >= 0);
}
static void vhost_scsi_stop(VHostSCSI *s)
{
VirtIODevice *vdev = VIRTIO_DEVICE(s);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
int ret = 0;
if (k->set_guest_notifiers) {
ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
if (ret < 0) {
error_report("vhost guest notifier cleanup failed: %d\n", ret);
}
}
assert(ret >= 0);
vhost_scsi_clear_endpoint(s);
vhost_dev_stop(&s->dev, vdev);
vhost_dev_disable_notifiers(&s->dev, vdev);
}
/*
* This function switches ioeventfd on/off in the device.
* The caller must set or clear the handlers for the EventNotifier.
*/
int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
{
VirtIODevice *vdev = virtio_bus_get_device(bus);
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
VirtQueue *vq = virtio_get_queue(vdev, n);
EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
int r = 0;
if (!k->ioeventfd_assign) {
return -ENOSYS;
}
if (assign) {
assert(!bus->ioeventfd_started);
r = event_notifier_init(notifier, 1);
if (r < 0) {
error_report("%s: unable to init event notifier: %s (%d)",
__func__, strerror(-r), r);
return r;
}
r = k->ioeventfd_assign(proxy, notifier, n, true);
if (r < 0) {
error_report("%s: unable to assign ioeventfd: %d", __func__, r);
goto cleanup_event_notifier;
}
return 0;
} else {
if (!bus->ioeventfd_started) {
return 0;
}
k->ioeventfd_assign(proxy, notifier, n, false);
}
cleanup_event_notifier:
/* Test and clear notifier after disabling event,
* in case poll callback didn't have time to run.
*/
virtio_queue_host_notifier_read(notifier);
event_notifier_cleanup(notifier);
return r;
}
/* Context: QEMU global mutex held */
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);
/* Better luck next time. */
if (s->disabled) {
s->disabled = false;
return;
}
if (!s->started || s->stopping) {
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, true, 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;
s->stopping = false;
}
void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
VirtIODevice *vdev;
int n, r;
if (!k->ioeventfd_started || !k->ioeventfd_started(proxy)) {
return;
}
vdev = virtio_bus_get_device(bus);
for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
if (!virtio_queue_get_num(vdev, n)) {
continue;
}
r = set_host_notifier_internal(proxy, bus, n, false, false);
assert(r >= 0);
}
k->ioeventfd_set_started(proxy, false, false);
}
/* On success, ioeventfd ownership belongs to the caller. */
int virtio_bus_grab_ioeventfd(VirtioBusState *bus)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
/* vhost can be used even if ioeventfd=off in the proxy device,
* so do not check k->ioeventfd_enabled.
*/
if (!k->ioeventfd_assign) {
return -ENOSYS;
}
if (bus->ioeventfd_grabbed == 0 && bus->ioeventfd_started) {
virtio_bus_stop_ioeventfd(bus);
/* Remember that we need to restart ioeventfd
* when ioeventfd_grabbed becomes zero.
*/
bus->ioeventfd_started = true;
}
bus->ioeventfd_grabbed++;
return 0;
}
/* A VirtIODevice is being plugged */
void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp)
{
DeviceState *qdev = DEVICE(vdev);
BusState *qbus = BUS(qdev_get_parent_bus(qdev));
VirtioBusState *bus = VIRTIO_BUS(qbus);
VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
DPRINTF("%s: plug device.\n", qbus->name);
if (klass->device_plugged != NULL) {
klass->device_plugged(qbus->parent, errp);
}
/* Get the features of the plugged device. */
assert(vdc->get_features != NULL);
vdev->host_features = vdc->get_features(vdev, vdev->host_features,
errp);
if (klass->post_plugged != NULL) {
klass->post_plugged(qbus->parent, errp);
}
}
void virtio_bus_start_ioeventfd(VirtioBusState *bus)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
VirtIODevice *vdev;
int n, r;
if (!k->ioeventfd_started || k->ioeventfd_started(proxy)) {
return;
}
if (k->ioeventfd_disabled(proxy)) {
return;
}
vdev = virtio_bus_get_device(bus);
for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
if (!virtio_queue_get_num(vdev, n)) {
continue;
}
r = set_host_notifier_internal(proxy, bus, n, true, true);
if (r < 0) {
goto assign_error;
}
}
k->ioeventfd_set_started(proxy, true, false);
return;
assign_error:
while (--n >= 0) {
if (!virtio_queue_get_num(vdev, n)) {
continue;
}
r = set_host_notifier_internal(proxy, bus, n, false, false);
assert(r >= 0);
}
k->ioeventfd_set_started(proxy, false, true);
error_report("%s: failed. Fallback to userspace (slower).", __func__);
}
/* Context: QEMU global mutex held */
void virtio_scsi_dataplane_stop(VirtIOSCSI *s)
{
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
int i;
if (!s->dataplane_started || s->dataplane_stopping) {
return;
}
/* Better luck next time. */
if (s->dataplane_fenced) {
s->dataplane_fenced = false;
s->dataplane_started = false;
return;
}
s->dataplane_stopping = true;
assert(s->ctx == iothread_get_aio_context(vs->conf.iothread));
aio_context_acquire(s->ctx);
virtio_scsi_clear_aio(s);
blk_drain_all(); /* ensure there are no in-flight requests */
aio_context_release(s->ctx);
for (i = 0; i < vs->conf.num_queues + 2; i++) {
k->set_host_notifier(qbus->parent, i, false);
}
/* Clean up guest notifier (irq) */
k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
s->dataplane_stopping = false;
s->dataplane_started = false;
}
/*
* This function switches from/to the generic ioeventfd handler.
* assign==false means 'use generic ioeventfd handler'.
*/
int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
if (!k->ioeventfd_started) {
return -ENOSYS;
}
k->ioeventfd_set_disabled(proxy, assign);
if (assign) {
/*
* Stop using the generic ioeventfd, we are doing eventfd handling
* ourselves below
*
* FIXME: We should just switch the handler and not deassign the
* ioeventfd.
* Otherwise, there's a window where we don't have an
* ioeventfd and we may end up with a notification where
* we don't expect one.
*/
virtio_bus_stop_ioeventfd(bus);
}
return set_host_notifier_internal(proxy, bus, n, assign, false);
}
static int vhost_scsi_start(VHostSCSI *s)
{
int ret, abi_version, i;
VirtIODevice *vdev = VIRTIO_DEVICE(s);
BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
if (!k->set_guest_notifiers) {
error_report("binding does not support guest notifiers");
return -ENOSYS;
}
ret = ioctl(s->dev.control, VHOST_SCSI_GET_ABI_VERSION, &abi_version);
if (ret < 0) {
return -errno;
}
if (abi_version > VHOST_SCSI_ABI_VERSION) {
error_report("vhost-scsi: The running tcm_vhost kernel abi_version:"
" %d is greater than vhost_scsi userspace supports: %d, please"
" upgrade your version of QEMU\n", abi_version,
VHOST_SCSI_ABI_VERSION);
return -ENOSYS;
}
ret = vhost_dev_enable_notifiers(&s->dev, vdev);
if (ret < 0) {
return ret;
}
s->dev.acked_features = vdev->guest_features;
ret = vhost_dev_start(&s->dev, vdev);
if (ret < 0) {
error_report("Error start vhost dev");
goto err_notifiers;
}
ret = vhost_scsi_set_endpoint(s);
if (ret < 0) {
error_report("Error set vhost-scsi endpoint");
goto err_vhost_stop;
}
ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
if (ret < 0) {
error_report("Error binding guest notifier");
goto err_endpoint;
}
/* guest_notifier_mask/pending not used yet, so just unmask
* everything here. virtio-pci will do the right thing by
* enabling/disabling irqfd.
*/
for (i = 0; i < s->dev.nvqs; i++) {
vhost_virtqueue_mask(&s->dev, vdev, i, false);
}
return ret;
err_endpoint:
vhost_scsi_clear_endpoint(s);
err_vhost_stop:
vhost_dev_stop(&s->dev, vdev);
err_notifiers:
vhost_dev_disable_notifiers(&s->dev, vdev);
return ret;
}