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 void virtio_9p_push_and_notify(V9fsPDU *pdu)
  24 {
  25     V9fsState *s = pdu->s;
  26
  27     /* push onto queue and notify */
  28     virtqueue_push(s->vq, &pdu->elem, pdu->size);
  29
  30     /* FIXME: we should batch these completions */
  31     virtio_notify(VIRTIO_DEVICE(s), s->vq);
  32 }
  33
  34 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features,
  35                                        Error **errp)
  36 {
  37     virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG);
  38     return features;
  39 }
  40
  41 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
  42 {
  43     int len;
  44     struct virtio_9p_config *cfg;
  45     V9fsState *s = VIRTIO_9P(vdev);
  46
  47     len = strlen(s->tag);
  48     cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
  49     virtio_stw_p(vdev, &cfg->tag_len, len);
  50     /* We don't copy the terminating null to config space */
  51     memcpy(cfg->tag, s->tag, len);
  52     memcpy(config, cfg, s->config_size);
  53     g_free(cfg);
  54 }
  55
  56 static void virtio_9p_save(QEMUFile *f, void *opaque)
  57 {
  58     virtio_save(VIRTIO_DEVICE(opaque), f);
  59 }
  60
  61 static int virtio_9p_load(QEMUFile *f, void *opaque, int version_id)
  62 {
  63     return virtio_load(VIRTIO_DEVICE(opaque), f, version_id);
  64 }
  65
  66 static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
  67 {
  68     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
  69     V9fsState *s = VIRTIO_9P(dev);
  70     int i, len;
  71     struct stat stat;
  72     FsDriverEntry *fse;
  73     V9fsPath path;
  74
  75     virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P,
  76                 sizeof(struct virtio_9p_config) + MAX_TAG_LEN);
  77
  78     /* initialize pdu allocator */
  79     QLIST_INIT(&s->free_list);
  80     QLIST_INIT(&s->active_list);
  81     for (i = 0; i < (MAX_REQ - 1); i++) {
  82         QLIST_INSERT_HEAD(&s->free_list, &s->pdus[i], next);
  83         s->pdus[i].s = s;
  84     }
  85
  86     s->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
  87
  88     v9fs_path_init(&path);
  89
  90     fse = get_fsdev_fsentry(s->fsconf.fsdev_id);
  91
  92     if (!fse) {
  93         /* We don't have a fsdev identified by fsdev_id */
  94         error_setg(errp, "Virtio-9p device couldn't find fsdev with the "
  95                    "id = %s",
  96                    s->fsconf.fsdev_id ? s->fsconf.fsdev_id : "NULL");
  97         goto out;
  98     }
  99
 100     if (!s->fsconf.tag) {
 101         /* we haven't specified a mount_tag */
 102         error_setg(errp, "fsdev with id %s needs mount_tag arguments",
 103                    s->fsconf.fsdev_id);
 104         goto out;
 105     }
 106
 107     s->ctx.export_flags = fse->export_flags;
 108     s->ctx.fs_root = g_strdup(fse->path);
 109     s->ctx.exops.get_st_gen = NULL;
 110     len = strlen(s->fsconf.tag);
 111     if (len > MAX_TAG_LEN - 1) {
 112         error_setg(errp, "mount tag '%s' (%d bytes) is longer than "
 113                    "maximum (%d bytes)", s->fsconf.tag, len, MAX_TAG_LEN - 1);
 114         goto out;
 115     }
 116
 117     s->tag = g_strdup(s->fsconf.tag);
 118     s->ctx.uid = -1;
 119
 120     s->ops = fse->ops;
 121     s->config_size = sizeof(struct virtio_9p_config) + len;
 122     s->fid_list = NULL;
 123     qemu_co_rwlock_init(&s->rename_lock);
 124
 125     if (s->ops->init(&s->ctx) < 0) {
 126         error_setg(errp, "Virtio-9p Failed to initialize fs-driver with id:%s"
 127                    " and export path:%s", s->fsconf.fsdev_id, s->ctx.fs_root);
 128         goto out;
 129     }
 130
 131     /*
 132      * Check details of export path, We need to use fs driver
 133      * call back to do that. Since we are in the init path, we don't
 134      * use co-routines here.
 135      */
 136     if (s->ops->name_to_path(&s->ctx, NULL, "/", &path) < 0) {
 137         error_setg(errp,
 138                    "error in converting name to path %s", strerror(errno));
 139         goto out;
 140     }
 141     if (s->ops->lstat(&s->ctx, &path, &stat)) {
 142         error_setg(errp, "share path %s does not exist", fse->path);
 143         goto out;
 144     } else if (!S_ISDIR(stat.st_mode)) {
 145         error_setg(errp, "share path %s is not a directory", fse->path);
 146         goto out;
 147     }
 148     v9fs_path_free(&path);
 149
 150     register_savevm(dev, "virtio-9p", -1, 1, virtio_9p_save, virtio_9p_load, s);
 151     return;
 152 out:
 153     g_free(s->ctx.fs_root);
 154     g_free(s->tag);
 155     virtio_cleanup(vdev);
 156     v9fs_path_free(&path);
 157 }
 158
 159 static void virtio_9p_device_unrealize(DeviceState *dev, Error **errp)
 160 {
 161     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 162     V9fsState *s = VIRTIO_9P(dev);
 163
 164     virtio_cleanup(vdev);
 165     unregister_savevm(dev, "virtio-9p", s);
 166     g_free(s->ctx.fs_root);
 167     g_free(s->tag);
 168 }
 169
 170 ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset,
 171                             const char *fmt, va_list ap)
 172 {
 173     return v9fs_iov_vmarshal(pdu->elem.in_sg, pdu->elem.in_num,
 174                              offset, 1, fmt, ap);
 175 }
 176
 177 ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
 178                               const char *fmt, va_list ap)
 179 {
 180     return v9fs_iov_vunmarshal(pdu->elem.out_sg, pdu->elem.out_num,
 181                                offset, 1, fmt, ap);
 182 }
 183
 184 void virtio_init_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
 185                               unsigned int *pniov, bool is_write)
 186 {
 187     if (is_write) {
 188         *piov = pdu->elem.out_sg;
 189         *pniov = pdu->elem.out_num;
 190     } else {
 191         *piov = pdu->elem.in_sg;
 192         *pniov = pdu->elem.in_num;
 193     }
 194 }
 195
 196 /* virtio-9p device */
 197
 198 static Property virtio_9p_properties[] = {
 199     DEFINE_PROP_STRING("mount_tag", V9fsState, fsconf.tag),
 200     DEFINE_PROP_STRING("fsdev", V9fsState, fsconf.fsdev_id),
 201     DEFINE_PROP_END_OF_LIST(),
 202 };
 203
 204 static void virtio_9p_class_init(ObjectClass *klass, void *data)
 205 {
 206     DeviceClass *dc = DEVICE_CLASS(klass);
 207     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 208
 209     dc->props = virtio_9p_properties;
 210     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 211     vdc->realize = virtio_9p_device_realize;
 212     vdc->unrealize = virtio_9p_device_unrealize;
 213     vdc->get_features = virtio_9p_get_features;
 214     vdc->get_config = virtio_9p_get_config;
 215 }
 216
 217 static const TypeInfo virtio_device_info = {
 218     .name = TYPE_VIRTIO_9P,
 219     .parent = TYPE_VIRTIO_DEVICE,
 220     .instance_size = sizeof(V9fsState),
 221     .class_init = virtio_9p_class_init,
 222 };
 223
 224 static void virtio_9p_register_types(void)
 225 {
 226     type_register_static(&virtio_device_info);
 227 }
 228
 229 type_init(virtio_9p_register_types)