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 "qemu/osdep.h"
  15 #include "hw/virtio/virtio.h"
  16 #include "qemu/sockets.h"
  17 #include "virtio-9p.h"
  18 #include "fsdev/qemu-fsdev.h"
  19 #include "coth.h"
  20 #include "hw/virtio/virtio-access.h"
  21 #include "qemu/iov.h"
  22 #include "qemu/module.h"
  23
  24 static void virtio_9p_push_and_notify(V9fsPDU *pdu)
  25 {
  26     V9fsState *s = pdu->s;
  27     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
  28     VirtQueueElement *elem = v->elems[pdu->idx];
  29
  30     /* push onto queue and notify */
  31     virtqueue_push(v->vq, elem, pdu->size);
  32     g_free(elem);
  33     v->elems[pdu->idx] = NULL;
  34
  35     /* FIXME: we should batch these completions */
  36     virtio_notify(VIRTIO_DEVICE(v), v->vq);
  37 }
  38
  39 static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq)
  40 {
  41     V9fsVirtioState *v = (V9fsVirtioState *)vdev;
  42     V9fsState *s = &v->state;
  43     V9fsPDU *pdu;
  44     ssize_t len;
  45     VirtQueueElement *elem;
  46
  47     while ((pdu = pdu_alloc(s))) {
  48         P9MsgHeader out;
  49
  50         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
  51         if (!elem) {
  52             goto out_free_pdu;
  53         }
  54
  55         if (iov_size(elem->in_sg, elem->in_num) < 7) {
  56             virtio_error(vdev,
  57                          "The guest sent a VirtFS request without space for "
  58                          "the reply");
  59             goto out_free_req;
  60         }
  61
  62         len = iov_to_buf(elem->out_sg, elem->out_num, 0, &out, 7);
  63         if (len != 7) {
  64             virtio_error(vdev, "The guest sent a malformed VirtFS request: "
  65                          "header size is %zd, should be 7", len);
  66             goto out_free_req;
  67         }
  68
  69         v->elems[pdu->idx] = elem;
  70
  71         pdu_submit(pdu, &out);
  72     }
  73
  74     return;
  75
  76 out_free_req:
  77     virtqueue_detach_element(vq, elem, 0);
  78     g_free(elem);
  79 out_free_pdu:
  80     pdu_free(pdu);
  81 }
  82
  83 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features,
  84                                        Error **errp)
  85 {
  86     virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG);
  87     return features;
  88 }
  89
  90 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
  91 {
  92     int len;
  93     struct virtio_9p_config *cfg;
  94     V9fsVirtioState *v = VIRTIO_9P(vdev);
  95     V9fsState *s = &v->state;
  96
  97     len = strlen(s->tag);
  98     cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
  99     virtio_stw_p(vdev, &cfg->tag_len, len);
 100     /* We don't copy the terminating null to config space */
 101     memcpy(cfg->tag, s->tag, len);
 102     memcpy(config, cfg, v->config_size);
 103     g_free(cfg);
 104 }
 105
 106 static void virtio_9p_reset(VirtIODevice *vdev)
 107 {
 108     V9fsVirtioState *v = (V9fsVirtioState *)vdev;
 109
 110     v9fs_reset(&v->state);
 111 }
 112
 113 static ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset,
 114                                    const char *fmt, va_list ap)
 115 {
 116     V9fsState *s = pdu->s;
 117     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 118     VirtQueueElement *elem = v->elems[pdu->idx];
 119     ssize_t ret;
 120
 121     ret = v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
 122     if (ret < 0) {
 123         VirtIODevice *vdev = VIRTIO_DEVICE(v);
 124
 125         virtio_error(vdev, "Failed to encode VirtFS reply type %d",
 126                      pdu->id + 1);
 127     }
 128     return ret;
 129 }
 130
 131 static ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
 132                                      const char *fmt, va_list ap)
 133 {
 134     V9fsState *s = pdu->s;
 135     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 136     VirtQueueElement *elem = v->elems[pdu->idx];
 137     ssize_t ret;
 138
 139     ret = v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap);
 140     if (ret < 0) {
 141         VirtIODevice *vdev = VIRTIO_DEVICE(v);
 142
 143         virtio_error(vdev, "Failed to decode VirtFS request type %d", pdu->id);
 144     }
 145     return ret;
 146 }
 147
 148 static void virtio_init_in_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
 149                                         unsigned int *pniov, size_t size)
 150 {
 151     V9fsState *s = pdu->s;
 152     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 153     VirtQueueElement *elem = v->elems[pdu->idx];
 154     size_t buf_size = iov_size(elem->in_sg, elem->in_num);
 155
 156     if (buf_size < size) {
 157         VirtIODevice *vdev = VIRTIO_DEVICE(v);
 158
 159         virtio_error(vdev,
 160                      "VirtFS reply type %d needs %zu bytes, buffer has %zu",
 161                      pdu->id + 1, size, buf_size);
 162     }
 163
 164     *piov = elem->in_sg;
 165     *pniov = elem->in_num;
 166 }
 167
 168 static void virtio_init_out_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
 169                                          unsigned int *pniov, size_t size)
 170 {
 171     V9fsState *s = pdu->s;
 172     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 173     VirtQueueElement *elem = v->elems[pdu->idx];
 174     size_t buf_size = iov_size(elem->out_sg, elem->out_num);
 175
 176     if (buf_size < size) {
 177         VirtIODevice *vdev = VIRTIO_DEVICE(v);
 178
 179         virtio_error(vdev,
 180                      "VirtFS request type %d needs %zu bytes, buffer has %zu",
 181                      pdu->id, size, buf_size);
 182     }
 183
 184     *piov = elem->out_sg;
 185     *pniov = elem->out_num;
 186 }
 187
 188 static const V9fsTransport virtio_9p_transport = {
 189     .pdu_vmarshal = virtio_pdu_vmarshal,
 190     .pdu_vunmarshal = virtio_pdu_vunmarshal,
 191     .init_in_iov_from_pdu = virtio_init_in_iov_from_pdu,
 192     .init_out_iov_from_pdu = virtio_init_out_iov_from_pdu,
 193     .push_and_notify = virtio_9p_push_and_notify,
 194 };
 195
 196 static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
 197 {
 198     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 199     V9fsVirtioState *v = VIRTIO_9P(dev);
 200     V9fsState *s = &v->state;
 201
 202     if (v9fs_device_realize_common(s, &virtio_9p_transport, errp)) {
 203         return;
 204     }
 205
 206     v->config_size = sizeof(struct virtio_9p_config) + strlen(s->fsconf.tag);
 207     virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P, v->config_size);
 208     v->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
 209 }
 210
 211 static void virtio_9p_device_unrealize(DeviceState *dev, Error **errp)
 212 {
 213     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 214     V9fsVirtioState *v = VIRTIO_9P(dev);
 215     V9fsState *s = &v->state;
 216
 217     virtio_cleanup(vdev);
 218     v9fs_device_unrealize_common(s, errp);
 219 }
 220
 221 /* virtio-9p device */
 222
 223 static const VMStateDescription vmstate_virtio_9p = {
 224     .name = "virtio-9p",
 225     .minimum_version_id = 1,
 226     .version_id = 1,
 227     .fields = (VMStateField[]) {
 228         VMSTATE_VIRTIO_DEVICE,
 229         VMSTATE_END_OF_LIST()
 230     },
 231 };
 232
 233 static Property virtio_9p_properties[] = {
 234     DEFINE_PROP_STRING("mount_tag", V9fsVirtioState, state.fsconf.tag),
 235     DEFINE_PROP_STRING("fsdev", V9fsVirtioState, state.fsconf.fsdev_id),
 236     DEFINE_PROP_END_OF_LIST(),
 237 };
 238
 239 static void virtio_9p_class_init(ObjectClass *klass, void *data)
 240 {
 241     DeviceClass *dc = DEVICE_CLASS(klass);
 242     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 243
 244     dc->props = virtio_9p_properties;
 245     dc->vmsd = &vmstate_virtio_9p;
 246     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 247     vdc->realize = virtio_9p_device_realize;
 248     vdc->unrealize = virtio_9p_device_unrealize;
 249     vdc->get_features = virtio_9p_get_features;
 250     vdc->get_config = virtio_9p_get_config;
 251     vdc->reset = virtio_9p_reset;
 252 }
 253
 254 static const TypeInfo virtio_device_info = {
 255     .name = TYPE_VIRTIO_9P,
 256     .parent = TYPE_VIRTIO_DEVICE,
 257     .instance_size = sizeof(V9fsVirtioState),
 258     .class_init = virtio_9p_class_init,
 259 };
 260
 261 static void virtio_9p_register_types(void)
 262 {
 263     type_register_static(&virtio_device_info);
 264 }
 265
 266 type_init(virtio_9p_register_types)