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