diff options
Diffstat (limited to 'backends/vhost-user.c')
| -rw-r--r-- | backends/vhost-user.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/backends/vhost-user.c b/backends/vhost-user.c new file mode 100644 index 0000000000..2b055544a7 --- /dev/null +++ b/backends/vhost-user.c @@ -0,0 +1,209 @@ +/* + * QEMU vhost-user backend + * + * Copyright (C) 2018 Red Hat Inc + * + * Authors: + * Marc-André Lureau <marcandre.lureau@redhat.com> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + + +#include "qemu/osdep.h" +#include "hw/qdev.h" +#include "qapi/error.h" +#include "qapi/qmp/qerror.h" +#include "qemu/error-report.h" +#include "qom/object_interfaces.h" +#include "sysemu/vhost-user-backend.h" +#include "sysemu/kvm.h" +#include "io/channel-command.h" +#include "hw/virtio/virtio-bus.h" + +static bool +ioeventfd_enabled(void) +{ + return kvm_enabled() && kvm_eventfds_enabled(); +} + +int +vhost_user_backend_dev_init(VhostUserBackend *b, VirtIODevice *vdev, + unsigned nvqs, Error **errp) +{ + int ret; + + assert(!b->vdev && vdev); + + if (!ioeventfd_enabled()) { + error_setg(errp, "vhost initialization failed: requires kvm"); + return -1; + } + + if (!vhost_user_init(&b->vhost_user, &b->chr, errp)) { + return -1; + } + + b->vdev = vdev; + b->dev.nvqs = nvqs; + b->dev.vqs = g_new(struct vhost_virtqueue, nvqs); + + ret = vhost_dev_init(&b->dev, &b->vhost_user, VHOST_BACKEND_TYPE_USER, 0); + if (ret < 0) { + error_setg_errno(errp, -ret, "vhost initialization failed"); + return -1; + } + + return 0; +} + +void +vhost_user_backend_start(VhostUserBackend *b) +{ + BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(b->vdev))); + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); + int ret, i ; + + if (b->started) { + return; + } + + if (!k->set_guest_notifiers) { + error_report("binding does not support guest notifiers"); + return; + } + + ret = vhost_dev_enable_notifiers(&b->dev, b->vdev); + if (ret < 0) { + return; + } + + ret = k->set_guest_notifiers(qbus->parent, b->dev.nvqs, true); + if (ret < 0) { + error_report("Error binding guest notifier"); + goto err_host_notifiers; + } + + b->dev.acked_features = b->vdev->guest_features; + ret = vhost_dev_start(&b->dev, b->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 < b->dev.nvqs; i++) { + vhost_virtqueue_mask(&b->dev, b->vdev, + b->dev.vq_index + i, false); + } + + b->started = true; + return; + +err_guest_notifiers: + k->set_guest_notifiers(qbus->parent, b->dev.nvqs, false); +err_host_notifiers: + vhost_dev_disable_notifiers(&b->dev, b->vdev); +} + +void +vhost_user_backend_stop(VhostUserBackend *b) +{ + BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(b->vdev))); + VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); + int ret = 0; + + if (!b->started) { + return; + } + + vhost_dev_stop(&b->dev, b->vdev); + + if (k->set_guest_notifiers) { + ret = k->set_guest_notifiers(qbus->parent, + b->dev.nvqs, false); + if (ret < 0) { + error_report("vhost guest notifier cleanup failed: %d", ret); + } + } + assert(ret >= 0); + + vhost_dev_disable_notifiers(&b->dev, b->vdev); + b->started = false; +} + +static void set_chardev(Object *obj, const char *value, Error **errp) +{ + VhostUserBackend *b = VHOST_USER_BACKEND(obj); + Chardev *chr; + + if (b->completed) { + error_setg(errp, QERR_PERMISSION_DENIED); + return; + } + + g_free(b->chr_name); + b->chr_name = g_strdup(value); + + chr = qemu_chr_find(b->chr_name); + if (chr == NULL) { + error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND, + "Chardev '%s' not found", b->chr_name); + return; + } + + if (!qemu_chr_fe_init(&b->chr, chr, errp)) { + return; + } + + b->completed = true; + /* could call vhost_dev_init() so early message can be exchanged */ +} + +static char *get_chardev(Object *obj, Error **errp) +{ + VhostUserBackend *b = VHOST_USER_BACKEND(obj); + Chardev *chr = qemu_chr_fe_get_driver(&b->chr); + + if (chr && chr->label) { + return g_strdup(chr->label); + } + + return NULL; +} + +static void vhost_user_backend_init(Object *obj) +{ + object_property_add_str(obj, "chardev", get_chardev, set_chardev, NULL); +} + +static void vhost_user_backend_finalize(Object *obj) +{ + VhostUserBackend *b = VHOST_USER_BACKEND(obj); + + g_free(b->dev.vqs); + g_free(b->chr_name); + + vhost_user_cleanup(&b->vhost_user); + qemu_chr_fe_deinit(&b->chr, true); +} + +static const TypeInfo vhost_user_backend_info = { + .name = TYPE_VHOST_USER_BACKEND, + .parent = TYPE_OBJECT, + .instance_size = sizeof(VhostUserBackend), + .instance_init = vhost_user_backend_init, + .instance_finalize = vhost_user_backend_finalize, + .class_size = sizeof(VhostUserBackendClass), +}; + +static void register_types(void) +{ + type_register_static(&vhost_user_backend_info); +} + +type_init(register_types); |