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 "hw/virtio/virtio.h" 15 #include "hw/i386/pc.h" 16 #include "qemu/sockets.h" 17 #include "virtio-9p.h" 18 #include "fsdev/qemu-fsdev.h" 19 #include "9p-xattr.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 33 /* FIXME: we should batch these completions */ 34 virtio_notify(VIRTIO_DEVICE(v), v->vq); 35 } 36 37 static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq) 38 { 39 V9fsVirtioState *v = (V9fsVirtioState *)vdev; 40 V9fsState *s = &v->state; 41 V9fsPDU *pdu; 42 ssize_t len; 43 44 while ((pdu = pdu_alloc(s))) { 45 struct { 46 uint32_t size_le; 47 uint8_t id; 48 uint16_t tag_le; 49 } QEMU_PACKED out; 50 VirtQueueElement *elem = &v->elems[pdu->idx]; 51 52 len = virtqueue_pop(vq, elem); 53 if (!len) { 54 pdu_free(pdu); 55 break; 56 } 57 58 BUG_ON(elem->out_num == 0 || elem->in_num == 0); 59 QEMU_BUILD_BUG_ON(sizeof out != 7); 60 61 len = iov_to_buf(elem->out_sg, elem->out_num, 0, 62 &out, sizeof out); 63 BUG_ON(len != sizeof out); 64 65 pdu->size = le32_to_cpu(out.size_le); 66 67 pdu->id = out.id; 68 pdu->tag = le16_to_cpu(out.tag_le); 69 70 qemu_co_queue_init(&pdu->complete); 71 pdu_submit(pdu); 72 } 73 } 74 75 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features, 76 Error **errp) 77 { 78 virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG); 79 return features; 80 } 81 82 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config) 83 { 84 int len; 85 struct virtio_9p_config *cfg; 86 V9fsVirtioState *v = VIRTIO_9P(vdev); 87 V9fsState *s = &v->state; 88 89 len = strlen(s->tag); 90 cfg = g_malloc0(sizeof(struct virtio_9p_config) + len); 91 virtio_stw_p(vdev, &cfg->tag_len, len); 92 /* We don't copy the terminating null to config space */ 93 memcpy(cfg->tag, s->tag, len); 94 memcpy(config, cfg, v->config_size); 95 g_free(cfg); 96 } 97 98 static void virtio_9p_save(QEMUFile *f, void *opaque) 99 { 100 virtio_save(VIRTIO_DEVICE(opaque), f); 101 } 102 103 static int virtio_9p_load(QEMUFile *f, void *opaque, int version_id) 104 { 105 return virtio_load(VIRTIO_DEVICE(opaque), f, version_id); 106 } 107 108 static void virtio_9p_device_realize(DeviceState *dev, Error **errp) 109 { 110 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 111 V9fsVirtioState *v = VIRTIO_9P(dev); 112 V9fsState *s = &v->state; 113 114 if (v9fs_device_realize_common(s, errp)) { 115 goto out; 116 } 117 118 v->config_size = sizeof(struct virtio_9p_config) + strlen(s->fsconf.tag); 119 virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P, v->config_size); 120 v->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output); 121 register_savevm(dev, "virtio-9p", -1, 1, virtio_9p_save, virtio_9p_load, v); 122 123 out: 124 return; 125 } 126 127 static void virtio_9p_device_unrealize(DeviceState *dev, Error **errp) 128 { 129 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 130 V9fsVirtioState *v = VIRTIO_9P(dev); 131 V9fsState *s = &v->state; 132 133 virtio_cleanup(vdev); 134 unregister_savevm(dev, "virtio-9p", v); 135 v9fs_device_unrealize_common(s, errp); 136 } 137 138 ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset, 139 const char *fmt, va_list ap) 140 { 141 V9fsState *s = pdu->s; 142 V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); 143 VirtQueueElement *elem = &v->elems[pdu->idx]; 144 145 return v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap); 146 } 147 148 ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset, 149 const char *fmt, va_list ap) 150 { 151 V9fsState *s = pdu->s; 152 V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); 153 VirtQueueElement *elem = &v->elems[pdu->idx]; 154 155 return v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap); 156 } 157 158 void virtio_init_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov, 159 unsigned int *pniov, bool is_write) 160 { 161 V9fsState *s = pdu->s; 162 V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); 163 VirtQueueElement *elem = &v->elems[pdu->idx]; 164 165 if (is_write) { 166 *piov = elem->out_sg; 167 *pniov = elem->out_num; 168 } else { 169 *piov = elem->in_sg; 170 *pniov = elem->in_num; 171 } 172 } 173 174 /* virtio-9p device */ 175 176 static Property virtio_9p_properties[] = { 177 DEFINE_PROP_STRING("mount_tag", V9fsVirtioState, state.fsconf.tag), 178 DEFINE_PROP_STRING("fsdev", V9fsVirtioState, state.fsconf.fsdev_id), 179 DEFINE_PROP_END_OF_LIST(), 180 }; 181 182 static void virtio_9p_class_init(ObjectClass *klass, void *data) 183 { 184 DeviceClass *dc = DEVICE_CLASS(klass); 185 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 186 187 dc->props = virtio_9p_properties; 188 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 189 vdc->realize = virtio_9p_device_realize; 190 vdc->unrealize = virtio_9p_device_unrealize; 191 vdc->get_features = virtio_9p_get_features; 192 vdc->get_config = virtio_9p_get_config; 193 } 194 195 static const TypeInfo virtio_device_info = { 196 .name = TYPE_VIRTIO_9P, 197 .parent = TYPE_VIRTIO_DEVICE, 198 .instance_size = sizeof(V9fsVirtioState), 199 .class_init = virtio_9p_class_init, 200 }; 201 202 static void virtio_9p_register_types(void) 203 { 204 type_register_static(&virtio_device_info); 205 } 206 207 type_init(virtio_9p_register_types) 208