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/i386/pc.h"
  16 #include "qemu/sockets.h"
  17 #include "virtio-9p.h"
  18 #include "fsdev/qemu-fsdev.h"
  19 #include "9p-xattr.h"
  20 #include "coth.h"
  21 #include "hw/virtio/virtio-access.h"
  22
  23 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features,
  24                                        Error **errp)
  25 {
  26     virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG);
  27     return features;
  28 }
  29
  30 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
  31 {
  32     int len;
  33     struct virtio_9p_config *cfg;
  34     V9fsState *s = VIRTIO_9P(vdev);
  35
  36     len = strlen(s->tag);
  37     cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
  38     virtio_stw_p(vdev, &cfg->tag_len, len);
  39     /* We don't copy the terminating null to config space */
  40     memcpy(cfg->tag, s->tag, len);
  41     memcpy(config, cfg, s->config_size);
  42     g_free(cfg);
  43 }
  44
  45 static void virtio_9p_save(QEMUFile *f, void *opaque)
  46 {
  47     virtio_save(VIRTIO_DEVICE(opaque), f);
  48 }
  49
  50 static int virtio_9p_load(QEMUFile *f, void *opaque, int version_id)
  51 {
  52     return virtio_load(VIRTIO_DEVICE(opaque), f, version_id);
  53 }
  54
  55 static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
  56 {
  57     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
  58     V9fsState *s = VIRTIO_9P(dev);
  59     int i, len;
  60     struct stat stat;
  61     FsDriverEntry *fse;
  62     V9fsPath path;
  63
  64     virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P,
  65                 sizeof(struct virtio_9p_config) + MAX_TAG_LEN);
  66
  67     /* initialize pdu allocator */
  68     QLIST_INIT(&s->free_list);
  69     QLIST_INIT(&s->active_list);
  70     for (i = 0; i < (MAX_REQ - 1); i++) {
  71         QLIST_INSERT_HEAD(&s->free_list, &s->pdus[i], next);
  72     }
  73
  74     s->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
  75
  76     v9fs_path_init(&path);
  77
  78     fse = get_fsdev_fsentry(s->fsconf.fsdev_id);
  79
  80     if (!fse) {
  81         /* We don't have a fsdev identified by fsdev_id */
  82         error_setg(errp, "Virtio-9p device couldn't find fsdev with the "
  83                    "id = %s",
  84                    s->fsconf.fsdev_id ? s->fsconf.fsdev_id : "NULL");
  85         goto out;
  86     }
  87
  88     if (!s->fsconf.tag) {
  89         /* we haven't specified a mount_tag */
  90         error_setg(errp, "fsdev with id %s needs mount_tag arguments",
  91                    s->fsconf.fsdev_id);
  92         goto out;
  93     }
  94
  95     s->ctx.export_flags = fse->export_flags;
  96     s->ctx.fs_root = g_strdup(fse->path);
  97     s->ctx.exops.get_st_gen = NULL;
  98     len = strlen(s->fsconf.tag);
  99     if (len > MAX_TAG_LEN - 1) {
 100         error_setg(errp, "mount tag '%s' (%d bytes) is longer than "
 101                    "maximum (%d bytes)", s->fsconf.tag, len, MAX_TAG_LEN - 1);
 102         goto out;
 103     }
 104
 105     s->tag = g_strdup(s->fsconf.tag);
 106     s->ctx.uid = -1;
 107
 108     s->ops = fse->ops;
 109     s->config_size = sizeof(struct virtio_9p_config) + len;
 110     s->fid_list = NULL;
 111     qemu_co_rwlock_init(&s->rename_lock);
 112
 113     if (s->ops->init(&s->ctx) < 0) {
 114         error_setg(errp, "Virtio-9p Failed to initialize fs-driver with id:%s"
 115                    " and export path:%s", s->fsconf.fsdev_id, s->ctx.fs_root);
 116         goto out;
 117     }
 118
 119     /*
 120      * Check details of export path, We need to use fs driver
 121      * call back to do that. Since we are in the init path, we don't
 122      * use co-routines here.
 123      */
 124     if (s->ops->name_to_path(&s->ctx, NULL, "/", &path) < 0) {
 125         error_setg(errp,
 126                    "error in converting name to path %s", strerror(errno));
 127         goto out;
 128     }
 129     if (s->ops->lstat(&s->ctx, &path, &stat)) {
 130         error_setg(errp, "share path %s does not exist", fse->path);
 131         goto out;
 132     } else if (!S_ISDIR(stat.st_mode)) {
 133         error_setg(errp, "share path %s is not a directory", fse->path);
 134         goto out;
 135     }
 136     v9fs_path_free(&path);
 137
 138     register_savevm(dev, "virtio-9p", -1, 1, virtio_9p_save, virtio_9p_load, s);
 139     return;
 140 out:
 141     g_free(s->ctx.fs_root);
 142     g_free(s->tag);
 143     virtio_cleanup(vdev);
 144     v9fs_path_free(&path);
 145 }
 146
 147 static void virtio_9p_device_unrealize(DeviceState *dev, Error **errp)
 148 {
 149     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 150     V9fsState *s = VIRTIO_9P(dev);
 151
 152     virtio_cleanup(vdev);
 153     unregister_savevm(dev, "virtio-9p", s);
 154     g_free(s->ctx.fs_root);
 155     g_free(s->tag);
 156 }
 157
 158 /* virtio-9p device */
 159
 160 static Property virtio_9p_properties[] = {
 161     DEFINE_PROP_STRING("mount_tag", V9fsState, fsconf.tag),
 162     DEFINE_PROP_STRING("fsdev", V9fsState, fsconf.fsdev_id),
 163     DEFINE_PROP_END_OF_LIST(),
 164 };
 165
 166 static void virtio_9p_class_init(ObjectClass *klass, void *data)
 167 {
 168     DeviceClass *dc = DEVICE_CLASS(klass);
 169     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 170
 171     dc->props = virtio_9p_properties;
 172     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 173     vdc->realize = virtio_9p_device_realize;
 174     vdc->unrealize = virtio_9p_device_unrealize;
 175     vdc->get_features = virtio_9p_get_features;
 176     vdc->get_config = virtio_9p_get_config;
 177 }
 178
 179 static const TypeInfo virtio_device_info = {
 180     .name = TYPE_VIRTIO_9P,
 181     .parent = TYPE_VIRTIO_DEVICE,
 182     .instance_size = sizeof(V9fsState),
 183     .class_init = virtio_9p_class_init,
 184 };
 185
 186 static void virtio_9p_register_types(void)
 187 {
 188     type_register_static(&virtio_device_info);
 189 }
 190
 191 type_init(virtio_9p_register_types)