--- /dev/null
+/*
+ * Vhost-user filesystem virtio device
+ *
+ * Copyright 2018-2019 Red Hat, Inc.
+ *
+ * Authors:
+ * Stefan Hajnoczi <stefanha@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version. See the COPYING file in the
+ * top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include <sys/ioctl.h>
+#include "standard-headers/linux/virtio_fs.h"
+#include "qapi/error.h"
+#include "hw/qdev-properties.h"
+#include "hw/virtio/virtio-bus.h"
+#include "hw/virtio/virtio-access.h"
+#include "qemu/error-report.h"
+#include "hw/virtio/vhost-user-fs.h"
+#include "monitor/monitor.h"
+
+static void vuf_get_config(VirtIODevice *vdev, uint8_t *config)
+{
+ VHostUserFS *fs = VHOST_USER_FS(vdev);
+ struct virtio_fs_config fscfg = {};
+
+ memcpy((char *)fscfg.tag, fs->conf.tag,
+ MIN(strlen(fs->conf.tag) + 1, sizeof(fscfg.tag)));
+
+ virtio_stl_p(vdev, &fscfg.num_request_queues, fs->conf.num_request_queues);
+
+ memcpy(config, &fscfg, sizeof(fscfg));
+}
+
+static void vuf_start(VirtIODevice *vdev)
+{
+ VHostUserFS *fs = VHOST_USER_FS(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(&fs->vhost_dev, vdev);
+ if (ret < 0) {
+ error_report("Error enabling host notifiers: %d", -ret);
+ return;
+ }
+
+ ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, true);
+ if (ret < 0) {
+ error_report("Error binding guest notifier: %d", -ret);
+ goto err_host_notifiers;
+ }
+
+ fs->vhost_dev.acked_features = vdev->guest_features;
+ ret = vhost_dev_start(&fs->vhost_dev, vdev);
+ if (ret < 0) {
+ error_report("Error starting vhost: %d", -ret);
+ 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 < fs->vhost_dev.nvqs; i++) {
+ vhost_virtqueue_mask(&fs->vhost_dev, vdev, i, false);
+ }
+
+ return;
+
+err_guest_notifiers:
+ k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false);
+err_host_notifiers:
+ vhost_dev_disable_notifiers(&fs->vhost_dev, vdev);
+}
+
+static void vuf_stop(VirtIODevice *vdev)
+{
+ VHostUserFS *fs = VHOST_USER_FS(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;
+ }
+
+ vhost_dev_stop(&fs->vhost_dev, vdev);
+
+ ret = k->set_guest_notifiers(qbus->parent, fs->vhost_dev.nvqs, false);
+ if (ret < 0) {
+ error_report("vhost guest notifier cleanup failed: %d", ret);
+ return;
+ }
+
+ vhost_dev_disable_notifiers(&fs->vhost_dev, vdev);
+}
+
+static void vuf_set_status(VirtIODevice *vdev, uint8_t status)
+{
+ VHostUserFS *fs = VHOST_USER_FS(vdev);
+ bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
+
+ if (!vdev->vm_running) {
+ should_start = false;
+ }
+
+ if (fs->vhost_dev.started == should_start) {
+ return;
+ }
+
+ if (should_start) {
+ vuf_start(vdev);
+ } else {
+ vuf_stop(vdev);
+ }
+}
+
+static uint64_t vuf_get_features(VirtIODevice *vdev,
+ uint64_t requested_features,
+ Error **errp)
+{
+ /* No feature bits used yet */
+ return requested_features;
+}
+
+static void vuf_handle_output(VirtIODevice *vdev, VirtQueue *vq)
+{
+ /*
+ * Not normally called; it's the daemon that handles the queue;
+ * however virtio's cleanup path can call this.
+ */
+}
+
+static void vuf_guest_notifier_mask(VirtIODevice *vdev, int idx,
+ bool mask)
+{
+ VHostUserFS *fs = VHOST_USER_FS(vdev);
+
+ vhost_virtqueue_mask(&fs->vhost_dev, vdev, idx, mask);
+}
+
+static bool vuf_guest_notifier_pending(VirtIODevice *vdev, int idx)
+{
+ VHostUserFS *fs = VHOST_USER_FS(vdev);
+
+ return vhost_virtqueue_pending(&fs->vhost_dev, idx);
+}
+
+static void vuf_device_realize(DeviceState *dev, Error **errp)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+ VHostUserFS *fs = VHOST_USER_FS(dev);
+ unsigned int i;
+ size_t len;
+ int ret;
+
+ if (!fs->conf.chardev.chr) {
+ error_setg(errp, "missing chardev");
+ return;
+ }
+
+ if (!fs->conf.tag) {
+ error_setg(errp, "missing tag property");
+ return;
+ }
+ len = strlen(fs->conf.tag);
+ if (len == 0) {
+ error_setg(errp, "tag property cannot be empty");
+ return;
+ }
+ if (len > sizeof_field(struct virtio_fs_config, tag)) {
+ error_setg(errp, "tag property must be %zu bytes or less",
+ sizeof_field(struct virtio_fs_config, tag));
+ return;
+ }
+
+ if (fs->conf.num_request_queues == 0) {
+ error_setg(errp, "num-request-queues property must be larger than 0");
+ return;
+ }
+
+ if (!is_power_of_2(fs->conf.queue_size)) {
+ error_setg(errp, "queue-size property must be a power of 2");
+ return;
+ }
+
+ if (fs->conf.queue_size > VIRTQUEUE_MAX_SIZE) {
+ error_setg(errp, "queue-size property must be %u or smaller",
+ VIRTQUEUE_MAX_SIZE);
+ return;
+ }
+
+ if (!vhost_user_init(&fs->vhost_user, &fs->conf.chardev, errp)) {
+ return;
+ }
+
+ virtio_init(vdev, "vhost-user-fs", VIRTIO_ID_FS,
+ sizeof(struct virtio_fs_config));
+
+ /* Hiprio queue */
+ virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output);
+
+ /* Request queues */
+ for (i = 0; i < fs->conf.num_request_queues; i++) {
+ virtio_add_queue(vdev, fs->conf.queue_size, vuf_handle_output);
+ }
+
+ /* 1 high prio queue, plus the number configured */
+ fs->vhost_dev.nvqs = 1 + fs->conf.num_request_queues;
+ fs->vhost_dev.vqs = g_new0(struct vhost_virtqueue, fs->vhost_dev.nvqs);
+ ret = vhost_dev_init(&fs->vhost_dev, &fs->vhost_user,
+ VHOST_BACKEND_TYPE_USER, 0);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "vhost_dev_init failed");
+ goto err_virtio;
+ }
+
+ return;
+
+err_virtio:
+ vhost_user_cleanup(&fs->vhost_user);
+ virtio_cleanup(vdev);
+ g_free(fs->vhost_dev.vqs);
+ return;
+}
+
+static void vuf_device_unrealize(DeviceState *dev, Error **errp)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+ VHostUserFS *fs = VHOST_USER_FS(dev);
+
+ /* This will stop vhost backend if appropriate. */
+ vuf_set_status(vdev, 0);
+
+ vhost_dev_cleanup(&fs->vhost_dev);
+
+ vhost_user_cleanup(&fs->vhost_user);
+
+ virtio_cleanup(vdev);
+ g_free(fs->vhost_dev.vqs);
+ fs->vhost_dev.vqs = NULL;
+}
+
+static const VMStateDescription vuf_vmstate = {
+ .name = "vhost-user-fs",
+ .unmigratable = 1,
+};
+
+static Property vuf_properties[] = {
+ DEFINE_PROP_CHR("chardev", VHostUserFS, conf.chardev),
+ DEFINE_PROP_STRING("tag", VHostUserFS, conf.tag),
+ DEFINE_PROP_UINT16("num-request-queues", VHostUserFS,
+ conf.num_request_queues, 1),
+ DEFINE_PROP_UINT16("queue-size", VHostUserFS, conf.queue_size, 128),
+ DEFINE_PROP_STRING("vhostfd", VHostUserFS, conf.vhostfd),
+ DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vuf_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+
+ dc->props = vuf_properties;
+ dc->vmsd = &vuf_vmstate;
+ set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
+ vdc->realize = vuf_device_realize;
+ vdc->unrealize = vuf_device_unrealize;
+ vdc->get_features = vuf_get_features;
+ vdc->get_config = vuf_get_config;
+ vdc->set_status = vuf_set_status;
+ vdc->guest_notifier_mask = vuf_guest_notifier_mask;
+ vdc->guest_notifier_pending = vuf_guest_notifier_pending;
+}
+
+static const TypeInfo vuf_info = {
+ .name = TYPE_VHOST_USER_FS,
+ .parent = TYPE_VIRTIO_DEVICE,
+ .instance_size = sizeof(VHostUserFS),
+ .class_init = vuf_class_init,
+};
+
+static void vuf_register_types(void)
+{
+ type_register_static(&vuf_info);
+}
+
+type_init(vuf_register_types)
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