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 {
  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_device_realize(DeviceState *dev, Error **errp)
  46 {
  47     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
  48     V9fsState *s = VIRTIO_9P(dev);
  49     int i, len;
  50     struct stat stat;
  51     FsDriverEntry *fse;
  52     V9fsPath path;
  53
  54     virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P,
  55                 sizeof(struct virtio_9p_config) + MAX_TAG_LEN);
  56
  57     /* initialize pdu allocator */
  58     QLIST_INIT(&s->free_list);
  59     QLIST_INIT(&s->active_list);
  60     for (i = 0; i < (MAX_REQ - 1); i++) {
  61         QLIST_INSERT_HEAD(&s->free_list, &s->pdus[i], next);
  62     }
  63
  64     s->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
  65
  66     v9fs_path_init(&path);
  67
  68     fse = get_fsdev_fsentry(s->fsconf.fsdev_id);
  69
  70     if (!fse) {
  71         /* We don't have a fsdev identified by fsdev_id */
  72         error_setg(errp, "Virtio-9p device couldn't find fsdev with the "
  73                    "id = %s",
  74                    s->fsconf.fsdev_id ? s->fsconf.fsdev_id : "NULL");
  75         goto out;
  76     }
  77
  78     if (!s->fsconf.tag) {
  79         /* we haven't specified a mount_tag */
  80         error_setg(errp, "fsdev with id %s needs mount_tag arguments",
  81                    s->fsconf.fsdev_id);
  82         goto out;
  83     }
  84
  85     s->ctx.export_flags = fse->export_flags;
  86     s->ctx.fs_root = g_strdup(fse->path);
  87     s->ctx.exops.get_st_gen = NULL;
  88     len = strlen(s->fsconf.tag);
  89     if (len > MAX_TAG_LEN - 1) {
  90         error_setg(errp, "mount tag '%s' (%d bytes) is longer than "
  91                    "maximum (%d bytes)", s->fsconf.tag, len, MAX_TAG_LEN - 1);
  92         goto out;
  93     }
  94
  95     s->tag = g_strdup(s->fsconf.tag);
  96     s->ctx.uid = -1;
  97
  98     s->ops = fse->ops;
  99     s->config_size = sizeof(struct virtio_9p_config) + len;
 100     s->fid_list = NULL;
 101     qemu_co_rwlock_init(&s->rename_lock);
 102
 103     if (s->ops->init(&s->ctx) < 0) {
 104         error_setg(errp, "Virtio-9p Failed to initialize fs-driver with id:%s"
 105                    " and export path:%s", s->fsconf.fsdev_id, s->ctx.fs_root);
 106         goto out;
 107     }
 108     if (v9fs_init_worker_threads() < 0) {
 109         error_setg(errp, "worker thread initialization failed");
 110         goto out;
 111     }
 112
 113     /*
 114      * Check details of export path, We need to use fs driver
 115      * call back to do that. Since we are in the init path, we don't
 116      * use co-routines here.
 117      */
 118     if (s->ops->name_to_path(&s->ctx, NULL, "/", &path) < 0) {
 119         error_setg(errp,
 120                    "error in converting name to path %s", strerror(errno));
 121         goto out;
 122     }
 123     if (s->ops->lstat(&s->ctx, &path, &stat)) {
 124         error_setg(errp, "share path %s does not exist", fse->path);
 125         goto out;
 126     } else if (!S_ISDIR(stat.st_mode)) {
 127         error_setg(errp, "share path %s is not a directory", fse->path);
 128         goto out;
 129     }
 130     v9fs_path_free(&path);
 131
 132     return;
 133 out:
 134     g_free(s->ctx.fs_root);
 135     g_free(s->tag);
 136     virtio_cleanup(vdev);
 137     v9fs_path_free(&path);
 138 }
 139
 140 /* virtio-9p device */
 141
 142 static Property virtio_9p_properties[] = {
 143     DEFINE_VIRTIO_9P_PROPERTIES(V9fsState, fsconf),
 144     DEFINE_PROP_END_OF_LIST(),
 145 };
 146
 147 static void virtio_9p_class_init(ObjectClass *klass, void *data)
 148 {
 149     DeviceClass *dc = DEVICE_CLASS(klass);
 150     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 151
 152     dc->props = virtio_9p_properties;
 153     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 154     vdc->realize = virtio_9p_device_realize;
 155     vdc->get_features = virtio_9p_get_features;
 156     vdc->get_config = virtio_9p_get_config;
 157 }
 158
 159 static const TypeInfo virtio_device_info = {
 160     .name = TYPE_VIRTIO_9P,
 161     .parent = TYPE_VIRTIO_DEVICE,
 162     .instance_size = sizeof(V9fsState),
 163     .class_init = virtio_9p_class_init,
 164 };
 165
 166 static void virtio_9p_register_types(void)
 167 {
 168     type_register_static(&virtio_device_info);
 169 }
 170
 171 type_init(virtio_9p_register_types)