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