net/vmnet-common.m

   1 /*
   2  * vmnet-common.m - network client wrapper for Apple vmnet.framework
   3  *
   4  * Copyright(c) 2022 Vladislav Yaroshchuk <[email protected]>
   5  * Copyright(c) 2021 Phillip Tennen <[email protected]>
   6  *
   7  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   8  * See the COPYING file in the top-level directory.
   9  *
  10  */
  11
  12 #include "qemu/osdep.h"
  13 #include "qemu/main-loop.h"
  14 #include "qemu/log.h"
  15 #include "qapi/qapi-types-net.h"
  16 #include "vmnet_int.h"
  17 #include "clients.h"
  18 #include "qemu/error-report.h"
  19 #include "qapi/error.h"
  20
  21 #include <vmnet/vmnet.h>
  22 #include <dispatch/dispatch.h>
  23
  24
  25 static void vmnet_send_completed(NetClientState *nc, ssize_t len);
  26
  27
  28 const char *vmnet_status_map_str(vmnet_return_t status)
  29 {
  30     switch (status) {
  31     case VMNET_SUCCESS:
  32         return "success";
  33     case VMNET_FAILURE:
  34         return "general failure (possibly not enough privileges)";
  35     case VMNET_MEM_FAILURE:
  36         return "memory allocation failure";
  37     case VMNET_INVALID_ARGUMENT:
  38         return "invalid argument specified";
  39     case VMNET_SETUP_INCOMPLETE:
  40         return "interface setup is not complete";
  41     case VMNET_INVALID_ACCESS:
  42         return "invalid access, permission denied";
  43     case VMNET_PACKET_TOO_BIG:
  44         return "packet size is larger than MTU";
  45     case VMNET_BUFFER_EXHAUSTED:
  46         return "buffers exhausted in kernel";
  47     case VMNET_TOO_MANY_PACKETS:
  48         return "packet count exceeds limit";
  49 #if defined(MAC_OS_VERSION_11_0) && \
  50     MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_VERSION_11_0
  51     case VMNET_SHARING_SERVICE_BUSY:
  52         return "conflict, sharing service is in use";
  53 #endif
  54     default:
  55         return "unknown vmnet error";
  56     }
  57 }
  58
  59
  60 /**
  61  * Write packets from QEMU to vmnet interface.
  62  *
  63  * vmnet.framework supports iov, but writing more than
  64  * one iov into vmnet interface fails with
  65  * 'VMNET_INVALID_ARGUMENT'. Collecting provided iovs into
  66  * one and passing it to vmnet works fine. That's the
  67  * reason why receive_iov() left unimplemented. But it still
  68  * works with good performance having .receive() only.
  69  */
  70 ssize_t vmnet_receive_common(NetClientState *nc,
  71                              const uint8_t *buf,
  72                              size_t size)
  73 {
  74     VmnetState *s = DO_UPCAST(VmnetState, nc, nc);
  75     struct vmpktdesc packet;
  76     struct iovec iov;
  77     int pkt_cnt;
  78     vmnet_return_t if_status;
  79
  80     if (size > s->max_packet_size) {
  81         warn_report("vmnet: packet is too big, %zu > %" PRIu64,
  82             packet.vm_pkt_size,
  83             s->max_packet_size);
  84         return -1;
  85     }
  86
  87     iov.iov_base = (char *) buf;
  88     iov.iov_len = size;
  89
  90     packet.vm_pkt_iovcnt = 1;
  91     packet.vm_flags = 0;
  92     packet.vm_pkt_size = size;
  93     packet.vm_pkt_iov = &iov;
  94     pkt_cnt = 1;
  95
  96     if_status = vmnet_write(s->vmnet_if, &packet, &pkt_cnt);
  97     if (if_status != VMNET_SUCCESS) {
  98         error_report("vmnet: write error: %s\n",
  99                      vmnet_status_map_str(if_status));
 100         return -1;
 101     }
 102
 103     if (pkt_cnt) {
 104         return size;
 105     }
 106     return 0;
 107 }
 108
 109
 110 /**
 111  * Read packets from vmnet interface and write them
 112  * to temporary buffers in VmnetState.
 113  *
 114  * Returns read packets number (may be 0) on success,
 115  * -1 on error
 116  */
 117 static int vmnet_read_packets(VmnetState *s)
 118 {
 119     assert(s->packets_send_current_pos == s->packets_send_end_pos);
 120
 121     struct vmpktdesc *packets = s->packets_buf;
 122     vmnet_return_t status;
 123     int i;
 124
 125     /* Read as many packets as present */
 126     s->packets_send_current_pos = 0;
 127     s->packets_send_end_pos = VMNET_PACKETS_LIMIT;
 128     for (i = 0; i < s->packets_send_end_pos; ++i) {
 129         packets[i].vm_pkt_size = s->max_packet_size;
 130         packets[i].vm_pkt_iovcnt = 1;
 131         packets[i].vm_flags = 0;
 132     }
 133
 134     status = vmnet_read(s->vmnet_if, packets, &s->packets_send_end_pos);
 135     if (status != VMNET_SUCCESS) {
 136         error_printf("vmnet: read failed: %s\n",
 137                      vmnet_status_map_str(status));
 138         s->packets_send_current_pos = 0;
 139         s->packets_send_end_pos = 0;
 140         return -1;
 141     }
 142     return s->packets_send_end_pos;
 143 }
 144
 145
 146 /**
 147  * Write packets from temporary buffers in VmnetState
 148  * to QEMU.
 149  */
 150 static void vmnet_write_packets_to_qemu(VmnetState *s)
 151 {
 152     while (s->packets_send_current_pos < s->packets_send_end_pos) {
 153         ssize_t size = qemu_send_packet_async(&s->nc,
 154                                       s->iov_buf[s->packets_send_current_pos].iov_base,
 155                                       s->packets_buf[s->packets_send_current_pos].vm_pkt_size,
 156                                       vmnet_send_completed);
 157
 158         if (size == 0) {
 159             /* QEMU is not ready to consume more packets -
 160              * stop and wait for completion callback call */
 161             return;
 162         }
 163         ++s->packets_send_current_pos;
 164     }
 165 }
 166
 167
 168 /**
 169  * Bottom half callback that transfers packets from vmnet interface
 170  * to QEMU.
 171  *
 172  * The process of transferring packets is three-staged:
 173  * 1. Handle vmnet event;
 174  * 2. Read packets from vmnet interface into temporary buffer;
 175  * 3. Write packets from temporary buffer to QEMU.
 176  *
 177  * QEMU may suspend this process on the last stage, returning 0 from
 178  * qemu_send_packet_async function. If this happens, we should
 179  * respectfully wait until it is ready to consume more packets,
 180  * write left ones in temporary buffer and only after this
 181  * continue reading more packets from vmnet interface.
 182  *
 183  * Packets to be transferred are stored into packets_buf,
 184  * in the window [packets_send_current_pos..packets_send_end_pos)
 185  * including current_pos, excluding end_pos.
 186  *
 187  * Thus, if QEMU is not ready, buffer is not read and
 188  * packets_send_current_pos < packets_send_end_pos.
 189  */
 190 static void vmnet_send_bh(void *opaque)
 191 {
 192     NetClientState *nc = (NetClientState *) opaque;
 193     VmnetState *s = DO_UPCAST(VmnetState, nc, nc);
 194
 195     /*
 196      * Do nothing if QEMU is not ready - wait
 197      * for completion callback invocation
 198      */
 199     if (s->packets_send_current_pos < s->packets_send_end_pos) {
 200         return;
 201     }
 202
 203     /* Read packets from vmnet interface */
 204     if (vmnet_read_packets(s) > 0) {
 205         /* Send them to QEMU */
 206         vmnet_write_packets_to_qemu(s);
 207     }
 208 }
 209
 210
 211 /**
 212  * Completion callback to be invoked by QEMU when it becomes
 213  * ready to consume more packets.
 214  */
 215 static void vmnet_send_completed(NetClientState *nc, ssize_t len)
 216 {
 217     VmnetState *s = DO_UPCAST(VmnetState, nc, nc);
 218
 219     /* Callback is invoked eq queued packet is sent */
 220     ++s->packets_send_current_pos;
 221
 222     /* Complete sending packets left in VmnetState buffers */
 223     vmnet_write_packets_to_qemu(s);
 224
 225     /* And read new ones from vmnet if VmnetState buffer is ready */
 226     if (s->packets_send_current_pos < s->packets_send_end_pos) {
 227         qemu_bh_schedule(s->send_bh);
 228     }
 229 }
 230
 231
 232 static void vmnet_bufs_init(VmnetState *s)
 233 {
 234     struct vmpktdesc *packets = s->packets_buf;
 235     struct iovec *iov = s->iov_buf;
 236     int i;
 237
 238     for (i = 0; i < VMNET_PACKETS_LIMIT; ++i) {
 239         iov[i].iov_len = s->max_packet_size;
 240         iov[i].iov_base = g_malloc0(iov[i].iov_len);
 241         packets[i].vm_pkt_iov = iov + i;
 242     }
 243 }
 244
 245
 246 int vmnet_if_create(NetClientState *nc,
 247                     xpc_object_t if_desc,
 248                     Error **errp)
 249 {
 250     VmnetState *s = DO_UPCAST(VmnetState, nc, nc);
 251     dispatch_semaphore_t if_created_sem = dispatch_semaphore_create(0);
 252     __block vmnet_return_t if_status;
 253
 254     s->if_queue = dispatch_queue_create(
 255         "org.qemu.vmnet.if_queue",
 256         DISPATCH_QUEUE_SERIAL
 257     );
 258
 259     xpc_dictionary_set_bool(
 260         if_desc,
 261         vmnet_allocate_mac_address_key,
 262         false
 263     );
 264
 265 #ifdef DEBUG
 266     qemu_log("vmnet.start.interface_desc:\n");
 267     xpc_dictionary_apply(if_desc,
 268                          ^bool(const char *k, xpc_object_t v) {
 269                              char *desc = xpc_copy_description(v);
 270                              qemu_log("  %s=%s\n", k, desc);
 271                              free(desc);
 272                              return true;
 273                          });
 274 #endif /* DEBUG */
 275
 276     s->vmnet_if = vmnet_start_interface(
 277         if_desc,
 278         s->if_queue,
 279         ^(vmnet_return_t status, xpc_object_t interface_param) {
 280             if_status = status;
 281             if (status != VMNET_SUCCESS || !interface_param) {
 282                 dispatch_semaphore_signal(if_created_sem);
 283                 return;
 284             }
 285
 286 #ifdef DEBUG
 287             qemu_log("vmnet.start.interface_param:\n");
 288             xpc_dictionary_apply(interface_param,
 289                                  ^bool(const char *k, xpc_object_t v) {
 290                                      char *desc = xpc_copy_description(v);
 291                                      qemu_log("  %s=%s\n", k, desc);
 292                                      free(desc);
 293                                      return true;
 294                                  });
 295 #endif /* DEBUG */
 296
 297             s->mtu = xpc_dictionary_get_uint64(
 298                 interface_param,
 299                 vmnet_mtu_key);
 300             s->max_packet_size = xpc_dictionary_get_uint64(
 301                 interface_param,
 302                 vmnet_max_packet_size_key);
 303
 304             dispatch_semaphore_signal(if_created_sem);
 305         });
 306
 307     if (s->vmnet_if == NULL) {
 308         dispatch_release(s->if_queue);
 309         dispatch_release(if_created_sem);
 310         error_setg(errp,
 311                    "unable to create interface with requested params");
 312         return -1;
 313     }
 314
 315     dispatch_semaphore_wait(if_created_sem, DISPATCH_TIME_FOREVER);
 316     dispatch_release(if_created_sem);
 317
 318     if (if_status != VMNET_SUCCESS) {
 319         dispatch_release(s->if_queue);
 320         error_setg(errp,
 321                    "cannot create vmnet interface: %s",
 322                    vmnet_status_map_str(if_status));
 323         return -1;
 324     }
 325
 326     s->send_bh = aio_bh_new(qemu_get_aio_context(), vmnet_send_bh, nc);
 327     vmnet_bufs_init(s);
 328
 329     s->packets_send_current_pos = 0;
 330     s->packets_send_end_pos = 0;
 331
 332     vmnet_interface_set_event_callback(
 333         s->vmnet_if,
 334         VMNET_INTERFACE_PACKETS_AVAILABLE,
 335         s->if_queue,
 336         ^(interface_event_t event_id, xpc_object_t event) {
 337             assert(event_id == VMNET_INTERFACE_PACKETS_AVAILABLE);
 338             /*
 339              * This function is being called from a non qemu thread, so
 340              * we only schedule a BH, and do the rest of the io completion
 341              * handling from vmnet_send_bh() which runs in a qemu context.
 342              */
 343             qemu_bh_schedule(s->send_bh);
 344         });
 345
 346     return 0;
 347 }
 348
 349
 350 void vmnet_cleanup_common(NetClientState *nc)
 351 {
 352     VmnetState *s = DO_UPCAST(VmnetState, nc, nc);
 353     dispatch_semaphore_t if_stopped_sem;
 354
 355     if (s->vmnet_if == NULL) {
 356         return;
 357     }
 358
 359     if_stopped_sem = dispatch_semaphore_create(0);
 360     vmnet_stop_interface(
 361         s->vmnet_if,
 362         s->if_queue,
 363         ^(vmnet_return_t status) {
 364             assert(status == VMNET_SUCCESS);
 365             dispatch_semaphore_signal(if_stopped_sem);
 366         });
 367     dispatch_semaphore_wait(if_stopped_sem, DISPATCH_TIME_FOREVER);
 368
 369     qemu_purge_queued_packets(nc);
 370
 371     qemu_bh_delete(s->send_bh);
 372     dispatch_release(if_stopped_sem);
 373     dispatch_release(s->if_queue);
 374
 375     for (int i = 0; i < VMNET_PACKETS_LIMIT; ++i) {
 376         g_free(s->iov_buf[i].iov_base);
 377     }
 378 }