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 #define VMSTATE_VIRTIO_DEVICE_USE_NEW
  15
  16 #include "qemu/osdep.h"
  17 #include "hw/virtio/virtio.h"
  18 #include "qemu/sockets.h"
  19 #include "virtio-9p.h"
  20 #include "fsdev/qemu-fsdev.h"
  21 #include "coth.h"
  22 #include "hw/virtio/virtio-access.h"
  23 #include "qemu/iov.h"
  24
  25 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         struct {
  50             uint32_t size_le;
  51             uint8_t id;
  52             uint16_t tag_le;
  53         } QEMU_PACKED out;
  54
  55         elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
  56         if (!elem) {
  57             goto out_free_pdu;
  58         }
  59
  60         if (elem->in_num == 0) {
  61             virtio_error(vdev,
  62                          "The guest sent a VirtFS request without space for "
  63                          "the reply");
  64             goto out_free_req;
  65         }
  66         QEMU_BUILD_BUG_ON(sizeof(out) != 7);
  67
  68         v->elems[pdu->idx] = elem;
  69         len = iov_to_buf(elem->out_sg, elem->out_num, 0,
  70                          &out, sizeof(out));
  71         if (len != sizeof(out)) {
  72             virtio_error(vdev, "The guest sent a malformed VirtFS request: "
  73                          "header size is %zd, should be 7", len);
  74             goto out_free_req;
  75         }
  76
  77         pdu->size = le32_to_cpu(out.size_le);
  78
  79         pdu->id = out.id;
  80         pdu->tag = le16_to_cpu(out.tag_le);
  81
  82         qemu_co_queue_init(&pdu->complete);
  83         pdu_submit(pdu);
  84     }
  85
  86     return;
  87
  88 out_free_req:
  89     virtqueue_detach_element(vq, elem, 0);
  90     g_free(elem);
  91 out_free_pdu:
  92     pdu_free(pdu);
  93 }
  94
  95 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features,
  96                                        Error **errp)
  97 {
  98     virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG);
  99     return features;
 100 }
 101
 102 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config)
 103 {
 104     int len;
 105     struct virtio_9p_config *cfg;
 106     V9fsVirtioState *v = VIRTIO_9P(vdev);
 107     V9fsState *s = &v->state;
 108
 109     len = strlen(s->tag);
 110     cfg = g_malloc0(sizeof(struct virtio_9p_config) + len);
 111     virtio_stw_p(vdev, &cfg->tag_len, len);
 112     /* We don't copy the terminating null to config space */
 113     memcpy(cfg->tag, s->tag, len);
 114     memcpy(config, cfg, v->config_size);
 115     g_free(cfg);
 116 }
 117
 118 static void virtio_9p_device_realize(DeviceState *dev, Error **errp)
 119 {
 120     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 121     V9fsVirtioState *v = VIRTIO_9P(dev);
 122     V9fsState *s = &v->state;
 123
 124     if (v9fs_device_realize_common(s, errp)) {
 125         goto out;
 126     }
 127
 128     v->config_size = sizeof(struct virtio_9p_config) + strlen(s->fsconf.tag);
 129     virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P, v->config_size);
 130     v->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output);
 131
 132 out:
 133     return;
 134 }
 135
 136 static void virtio_9p_device_unrealize(DeviceState *dev, Error **errp)
 137 {
 138     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 139     V9fsVirtioState *v = VIRTIO_9P(dev);
 140     V9fsState *s = &v->state;
 141
 142     virtio_cleanup(vdev);
 143     v9fs_device_unrealize_common(s, errp);
 144 }
 145
 146 ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset,
 147                             const char *fmt, va_list ap)
 148 {
 149     V9fsState *s = pdu->s;
 150     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 151     VirtQueueElement *elem = v->elems[pdu->idx];
 152
 153     return v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
 154 }
 155
 156 ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
 157                               const char *fmt, va_list ap)
 158 {
 159     V9fsState *s = pdu->s;
 160     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 161     VirtQueueElement *elem = v->elems[pdu->idx];
 162
 163     return v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap);
 164 }
 165
 166 void virtio_init_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
 167                               unsigned int *pniov, bool is_write)
 168 {
 169     V9fsState *s = pdu->s;
 170     V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
 171     VirtQueueElement *elem = v->elems[pdu->idx];
 172
 173     if (is_write) {
 174         *piov = elem->out_sg;
 175         *pniov = elem->out_num;
 176     } else {
 177         *piov = elem->in_sg;
 178         *pniov = elem->in_num;
 179     }
 180 }
 181
 182 /* virtio-9p device */
 183
 184 static const VMStateDescription vmstate_virtio_9p = {
 185     .name = "virtio-9p",
 186     .minimum_version_id = 1,
 187     .version_id = 1,
 188     .fields = (VMStateField[]) {
 189         VMSTATE_VIRTIO_DEVICE,
 190         VMSTATE_END_OF_LIST()
 191     },
 192 };
 193
 194 static Property virtio_9p_properties[] = {
 195     DEFINE_PROP_STRING("mount_tag", V9fsVirtioState, state.fsconf.tag),
 196     DEFINE_PROP_STRING("fsdev", V9fsVirtioState, state.fsconf.fsdev_id),
 197     DEFINE_PROP_END_OF_LIST(),
 198 };
 199
 200 static void virtio_9p_class_init(ObjectClass *klass, void *data)
 201 {
 202     DeviceClass *dc = DEVICE_CLASS(klass);
 203     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 204
 205     dc->props = virtio_9p_properties;
 206     dc->vmsd = &vmstate_virtio_9p;
 207     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 208     vdc->realize = virtio_9p_device_realize;
 209     vdc->unrealize = virtio_9p_device_unrealize;
 210     vdc->get_features = virtio_9p_get_features;
 211     vdc->get_config = virtio_9p_get_config;
 212 }
 213
 214 static const TypeInfo virtio_device_info = {
 215     .name = TYPE_VIRTIO_9P,
 216     .parent = TYPE_VIRTIO_DEVICE,
 217     .instance_size = sizeof(V9fsVirtioState),
 218     .class_init = virtio_9p_class_init,
 219 };
 220
 221 static void virtio_9p_register_types(void)
 222 {
 223     type_register_static(&virtio_device_info);
 224 }
 225
 226 type_init(virtio_9p_register_types)