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