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 "hw/i386/pc.h"
  17 #include "qemu/sockets.h"
  18 #include "virtio-9p.h"
  19 #include "fsdev/qemu-fsdev.h"
  20 #include "coth.h"
  21 #include "hw/virtio/virtio-access.h"
  22 #include "qemu/iov.h"
  23
  24 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
  46     while ((pdu = pdu_alloc(s))) {
  47         struct {
  48             uint32_t size_le;
  49             uint8_t id;
  50             uint16_t tag_le;
  51         } QEMU_PACKED out;
  52         VirtQueueElement *elem;
  53
  54         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
  55         if (!elem) {
  56             pdu_free(pdu);
  57             break;
  58         }
  59
  60         BUG_ON(elem->out_num == 0 || elem->in_num == 0);
  61         QEMU_BUILD_BUG_ON(sizeof out != 7);
  62
  63         v->elems[pdu->idx] = elem;
  64         len = iov_to_buf(elem->out_sg, elem->out_num, 0,
  65                          &out, sizeof out);
  66         BUG_ON(len != sizeof out);
  67
  68         pdu->size = le32_to_cpu(out.size_le);
  69
  70         pdu->id = out.id;
  71         pdu->tag = le16_to_cpu(out.tag_le);
  72
  73         qemu_co_queue_init(&pdu->complete);
  74         pdu_submit(pdu);
  75     }
  76 }
  77
  78 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features,
  79                                        Error **errp)
  80 {
  81     virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG);
  82     return features;
  83 }
  84
  85 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
  86 {
  87     int len;
  88     struct virtio_9p_config *cfg;
  89     V9fsVirtioState *v = VIRTIO_9P(vdev);
  90     V9fsState *s = &v->state;
  91
  92     len = strlen(s->tag);
  93     cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
  94     virtio_stw_p(vdev, &cfg->tag_len, len);
  95     /* We don't copy the terminating null to config space */
  96     memcpy(cfg->tag, s->tag, len);
  97     memcpy(config, cfg, v->config_size);
  98     g_free(cfg);
  99 }
 100
 101 static void virtio_9p_save(QEMUFile *f, void *opaque)
 102 {
 103     virtio_save(VIRTIO_DEVICE(opaque), f);
 104 }
 105
 106 static int virtio_9p_load(QEMUFile *f, void *opaque, int version_id)
 107 {
 108     return virtio_load(VIRTIO_DEVICE(opaque), f, version_id);
 109 }
 110
 111 static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
 112 {
 113     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 114     V9fsVirtioState *v = VIRTIO_9P(dev);
 115     V9fsState *s = &v->state;
 116
 117     if (v9fs_device_realize_common(s, errp)) {
 118         goto out;
 119     }
 120
 121     v->config_size = sizeof(struct virtio_9p_config) + strlen(s->fsconf.tag);
 122     virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P, v->config_size);
 123     v->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
 124     register_savevm(dev, "virtio-9p", -1, 1, virtio_9p_save, virtio_9p_load, v);
 125
 126 out:
 127     return;
 128 }
 129
 130 static void virtio_9p_device_unrealize(DeviceState *dev, Error **errp)
 131 {
 132     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 133     V9fsVirtioState *v = VIRTIO_9P(dev);
 134     V9fsState *s = &v->state;
 135
 136     virtio_cleanup(vdev);
 137     unregister_savevm(dev, "virtio-9p", v);
 138     v9fs_device_unrealize_common(s, errp);
 139 }
 140
 141 ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset,
 142                             const char *fmt, va_list ap)
 143 {
 144     V9fsState *s = pdu->s;
 145     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 146     VirtQueueElement *elem = v->elems[pdu->idx];
 147
 148     return v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
 149 }
 150
 151 ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
 152                               const char *fmt, va_list ap)
 153 {
 154     V9fsState *s = pdu->s;
 155     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 156     VirtQueueElement *elem = v->elems[pdu->idx];
 157
 158     return v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap);
 159 }
 160
 161 void virtio_init_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
 162                               unsigned int *pniov, bool is_write)
 163 {
 164     V9fsState *s = pdu->s;
 165     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 166     VirtQueueElement *elem = v->elems[pdu->idx];
 167
 168     if (is_write) {
 169         *piov = elem->out_sg;
 170         *pniov = elem->out_num;
 171     } else {
 172         *piov = elem->in_sg;
 173         *pniov = elem->in_num;
 174     }
 175 }
 176
 177 /* virtio-9p device */
 178
 179 static Property virtio_9p_properties[] = {
 180     DEFINE_PROP_STRING("mount_tag", V9fsVirtioState, state.fsconf.tag),
 181     DEFINE_PROP_STRING("fsdev", V9fsVirtioState, state.fsconf.fsdev_id),
 182     DEFINE_PROP_END_OF_LIST(),
 183 };
 184
 185 static void virtio_9p_class_init(ObjectClass *klass, void *data)
 186 {
 187     DeviceClass *dc = DEVICE_CLASS(klass);
 188     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 189
 190     dc->props = virtio_9p_properties;
 191     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 192     vdc->realize = virtio_9p_device_realize;
 193     vdc->unrealize = virtio_9p_device_unrealize;
 194     vdc->get_features = virtio_9p_get_features;
 195     vdc->get_config = virtio_9p_get_config;
 196 }
 197
 198 static const TypeInfo virtio_device_info = {
 199     .name = TYPE_VIRTIO_9P,
 200     .parent = TYPE_VIRTIO_DEVICE,
 201     .instance_size = sizeof(V9fsVirtioState),
 202     .class_init = virtio_9p_class_init,
 203 };
 204
 205 static void virtio_9p_register_types(void)
 206 {
 207     type_register_static(&virtio_device_info);
 208 }
 209
 210 type_init(virtio_9p_register_types)