hw/9pfs/virtio-9p-device.c

   1 /*
   2  * Virtio 9p backend
   3  *
   4  * Copyright IBM, Corp. 2010
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include "hw/virtio/virtio.h"
  15 #include "hw/virtio/virtio-9p.h"
  16 #include "hw/i386/pc.h"
  17 #include "qemu/sockets.h"
  18 #include "virtio-9p.h"
  19 #include "fsdev/qemu-fsdev.h"
  20 #include "virtio-9p-xattr.h"
  21 #include "virtio-9p-coth.h"
  22
  23 static uint32_t virtio_9p_get_features(VirtIODevice *vdev, uint32_t features)
  24 {
  25     features |= 1 << VIRTIO_9P_MOUNT_TAG;
  26     return features;
  27 }
  28
  29 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
  30 {
  31     int len;
  32     struct virtio_9p_config *cfg;
  33     V9fsState *s = VIRTIO_9P(vdev);
  34
  35     len = strlen(s->tag);
  36     cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
  37     stw_raw(&cfg->tag_len, len);
  38     /* We don't copy the terminating null to config space */
  39     memcpy(cfg->tag, s->tag, len);
  40     memcpy(config, cfg, s->config_size);
  41     g_free(cfg);
  42 }
  43
  44 static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
  45 {
  46     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
  47     V9fsState *s = VIRTIO_9P(dev);
  48     int i, len;
  49     struct stat stat;
  50     FsDriverEntry *fse;
  51     V9fsPath path;
  52
  53     virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P,
  54                 sizeof(struct virtio_9p_config) + MAX_TAG_LEN);
  55
  56     /* initialize pdu allocator */
  57     QLIST_INIT(&s->free_list);
  58     QLIST_INIT(&s->active_list);
  59     for (i = 0; i < (MAX_REQ - 1); i++) {
  60         QLIST_INSERT_HEAD(&s->free_list, &s->pdus[i], next);
  61     }
  62
  63     s->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
  64
  65     v9fs_path_init(&path);
  66
  67     fse = get_fsdev_fsentry(s->fsconf.fsdev_id);
  68
  69     if (!fse) {
  70         /* We don't have a fsdev identified by fsdev_id */
  71         error_setg(errp, "Virtio-9p device couldn't find fsdev with the "
  72                    "id = %s",
  73                    s->fsconf.fsdev_id ? s->fsconf.fsdev_id : "NULL");
  74         goto out;
  75     }
  76
  77     if (!s->fsconf.tag) {
  78         /* we haven't specified a mount_tag */
  79         error_setg(errp, "fsdev with id %s needs mount_tag arguments",
  80                    s->fsconf.fsdev_id);
  81         goto out;
  82     }
  83
  84     s->ctx.export_flags = fse->export_flags;
  85     s->ctx.fs_root = g_strdup(fse->path);
  86     s->ctx.exops.get_st_gen = NULL;
  87     len = strlen(s->fsconf.tag);
  88     if (len > MAX_TAG_LEN - 1) {
  89         error_setg(errp, "mount tag '%s' (%d bytes) is longer than "
  90                    "maximum (%d bytes)", s->fsconf.tag, len, MAX_TAG_LEN - 1);
  91         goto out;
  92     }
  93
  94     s->tag = g_strdup(s->fsconf.tag);
  95     s->ctx.uid = -1;
  96
  97     s->ops = fse->ops;
  98     s->config_size = sizeof(struct virtio_9p_config) + len;
  99     s->fid_list = NULL;
 100     qemu_co_rwlock_init(&s->rename_lock);
 101
 102     if (s->ops->init(&s->ctx) < 0) {
 103         error_setg(errp, "Virtio-9p Failed to initialize fs-driver with id:%s"
 104                    " and export path:%s", s->fsconf.fsdev_id, s->ctx.fs_root);
 105         goto out;
 106     }
 107     if (v9fs_init_worker_threads() < 0) {
 108         error_setg(errp, "worker thread initialization failed");
 109         goto out;
 110     }
 111
 112     /*
 113      * Check details of export path, We need to use fs driver
 114      * call back to do that. Since we are in the init path, we don't
 115      * use co-routines here.
 116      */
 117     if (s->ops->name_to_path(&s->ctx, NULL, "/", &path) < 0) {
 118         error_setg(errp,
 119                    "error in converting name to path %s", strerror(errno));
 120         goto out;
 121     }
 122     if (s->ops->lstat(&s->ctx, &path, &stat)) {
 123         error_setg(errp, "share path %s does not exist", fse->path);
 124         goto out;
 125     } else if (!S_ISDIR(stat.st_mode)) {
 126         error_setg(errp, "share path %s is not a directory", fse->path);
 127         goto out;
 128     }
 129     v9fs_path_free(&path);
 130
 131     return;
 132 out:
 133     g_free(s->ctx.fs_root);
 134     g_free(s->tag);
 135     virtio_cleanup(vdev);
 136     v9fs_path_free(&path);
 137 }
 138
 139 /* virtio-9p device */
 140
 141 static Property virtio_9p_properties[] = {
 142     DEFINE_VIRTIO_9P_PROPERTIES(V9fsState, fsconf),
 143     DEFINE_PROP_END_OF_LIST(),
 144 };
 145
 146 static void virtio_9p_class_init(ObjectClass *klass, void *data)
 147 {
 148     DeviceClass *dc = DEVICE_CLASS(klass);
 149     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 150
 151     dc->props = virtio_9p_properties;
 152     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 153     vdc->realize = virtio_9p_device_realize;
 154     vdc->get_features = virtio_9p_get_features;
 155     vdc->get_config = virtio_9p_get_config;
 156 }
 157
 158 static const TypeInfo virtio_device_info = {
 159     .name = TYPE_VIRTIO_9P,
 160     .parent = TYPE_VIRTIO_DEVICE,
 161     .instance_size = sizeof(V9fsState),
 162     .class_init = virtio_9p_class_init,
 163 };
 164
 165 static void virtio_9p_register_types(void)
 166 {
 167     type_register_static(&virtio_device_info);
 168 }
 169
 170 type_init(virtio_9p_register_types)