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 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         struct {
  48             uint32_t size_le;
  49             uint8_t id;
  50             uint16_t tag_le;
  51         } QEMU_PACKED out;
  52
  53         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
  54         if (!elem) {
  55             goto out_free_pdu;
  56         }
  57
  58         if (elem->in_num == 0) {
  59             virtio_error(vdev,
  60                          "The guest sent a VirtFS request without space for "
  61                          "the reply");
  62             goto out_free_req;
  63         }
  64         QEMU_BUILD_BUG_ON(sizeof(out) != 7);
  65
  66         v->elems[pdu->idx] = elem;
  67         len = iov_to_buf(elem->out_sg, elem->out_num, 0,
  68                          &out, sizeof(out));
  69         if (len != sizeof(out)) {
  70             virtio_error(vdev, "The guest sent a malformed VirtFS request: "
  71                          "header size is %zd, should be 7", len);
  72             goto out_free_req;
  73         }
  74
  75         pdu->size = le32_to_cpu(out.size_le);
  76
  77         pdu->id = out.id;
  78         pdu->tag = le16_to_cpu(out.tag_le);
  79
  80         qemu_co_queue_init(&pdu->complete);
  81         pdu_submit(pdu);
  82     }
  83
  84     return;
  85
  86 out_free_req:
  87     virtqueue_detach_element(vq, elem, 0);
  88     g_free(elem);
  89 out_free_pdu:
  90     pdu_free(pdu);
  91 }
  92
  93 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features,
  94                                        Error **errp)
  95 {
  96     virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG);
  97     return features;
  98 }
  99
 100 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
 101 {
 102     int len;
 103     struct virtio_9p_config *cfg;
 104     V9fsVirtioState *v = VIRTIO_9P(vdev);
 105     V9fsState *s = &v->state;
 106
 107     len = strlen(s->tag);
 108     cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
 109     virtio_stw_p(vdev, &cfg->tag_len, len);
 110     /* We don't copy the terminating null to config space */
 111     memcpy(cfg->tag, s->tag, len);
 112     memcpy(config, cfg, v->config_size);
 113     g_free(cfg);
 114 }
 115
 116 static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
 117 {
 118     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 119     V9fsVirtioState *v = VIRTIO_9P(dev);
 120     V9fsState *s = &v->state;
 121
 122     if (v9fs_device_realize_common(s, errp)) {
 123         goto out;
 124     }
 125
 126     v->config_size = sizeof(struct virtio_9p_config) + strlen(s->fsconf.tag);
 127     virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P, v->config_size);
 128     v->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
 129
 130 out:
 131     return;
 132 }
 133
 134 static void virtio_9p_device_unrealize(DeviceState *dev, Error **errp)
 135 {
 136     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 137     V9fsVirtioState *v = VIRTIO_9P(dev);
 138     V9fsState *s = &v->state;
 139
 140     virtio_cleanup(vdev);
 141     v9fs_device_unrealize_common(s, errp);
 142 }
 143
 144 ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset,
 145                             const char *fmt, va_list ap)
 146 {
 147     V9fsState *s = pdu->s;
 148     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 149     VirtQueueElement *elem = v->elems[pdu->idx];
 150
 151     return v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
 152 }
 153
 154 ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
 155                               const char *fmt, va_list ap)
 156 {
 157     V9fsState *s = pdu->s;
 158     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 159     VirtQueueElement *elem = v->elems[pdu->idx];
 160
 161     return v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap);
 162 }
 163
 164 void virtio_init_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
 165                               unsigned int *pniov, bool is_write)
 166 {
 167     V9fsState *s = pdu->s;
 168     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 169     VirtQueueElement *elem = v->elems[pdu->idx];
 170
 171     if (is_write) {
 172         *piov = elem->out_sg;
 173         *pniov = elem->out_num;
 174     } else {
 175         *piov = elem->in_sg;
 176         *pniov = elem->in_num;
 177     }
 178 }
 179
 180 /* virtio-9p device */
 181
 182 static const VMStateDescription vmstate_virtio_9p = {
 183     .name = "virtio-9p",
 184     .minimum_version_id = 1,
 185     .version_id = 1,
 186     .fields = (VMStateField[]) {
 187         VMSTATE_VIRTIO_DEVICE,
 188         VMSTATE_END_OF_LIST()
 189     },
 190 };
 191
 192 static Property virtio_9p_properties[] = {
 193     DEFINE_PROP_STRING("mount_tag", V9fsVirtioState, state.fsconf.tag),
 194     DEFINE_PROP_STRING("fsdev", V9fsVirtioState, state.fsconf.fsdev_id),
 195     DEFINE_PROP_END_OF_LIST(),
 196 };
 197
 198 static void virtio_9p_class_init(ObjectClass *klass, void *data)
 199 {
 200     DeviceClass *dc = DEVICE_CLASS(klass);
 201     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 202
 203     dc->props = virtio_9p_properties;
 204     dc->vmsd = &vmstate_virtio_9p;
 205     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 206     vdc->realize = virtio_9p_device_realize;
 207     vdc->unrealize = virtio_9p_device_unrealize;
 208     vdc->get_features = virtio_9p_get_features;
 209     vdc->get_config = virtio_9p_get_config;
 210 }
 211
 212 static const TypeInfo virtio_device_info = {
 213     .name = TYPE_VIRTIO_9P,
 214     .parent = TYPE_VIRTIO_DEVICE,
 215     .instance_size = sizeof(V9fsVirtioState),
 216     .class_init = virtio_9p_class_init,
 217 };
 218
 219 static void virtio_9p_register_types(void)
 220 {
 221     type_register_static(&virtio_device_info);
 222 }
 223
 224 type_init(virtio_9p_register_types)