hw/hyperv/syndbg.c

   1 /*
   2  * QEMU Hyper-V Synthetic Debugging device
   3  *
   4  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   5  * See the COPYING file in the top-level directory.
   6  */
   7
   8 #include "qemu/osdep.h"
   9 #include "qemu/ctype.h"
  10 #include "qemu/error-report.h"
  11 #include "qemu/main-loop.h"
  12 #include "qemu/sockets.h"
  13 #include "qapi/error.h"
  14 #include "migration/vmstate.h"
  15 #include "hw/qdev-properties.h"
  16 #include "hw/loader.h"
  17 #include "cpu.h"
  18 #include "hw/hyperv/hyperv.h"
  19 #include "hw/hyperv/vmbus-bridge.h"
  20 #include "hw/hyperv/hyperv-proto.h"
  21 #include "net/net.h"
  22 #include "net/eth.h"
  23 #include "net/checksum.h"
  24 #include "trace.h"
  25
  26 #define TYPE_HV_SYNDBG       "hv-syndbg"
  27
  28 typedef struct HvSynDbg {
  29     DeviceState parent_obj;
  30
  31     char *host_ip;
  32     uint16_t host_port;
  33     bool use_hcalls;
  34
  35     uint32_t target_ip;
  36     struct sockaddr_in servaddr;
  37     int socket;
  38     bool has_data_pending;
  39     uint64_t pending_page_gpa;
  40 } HvSynDbg;
  41
  42 #define HVSYNDBG(obj) OBJECT_CHECK(HvSynDbg, (obj), TYPE_HV_SYNDBG)
  43
  44 /* returns NULL unless there is exactly one HV Synth debug device */
  45 static HvSynDbg *hv_syndbg_find(void)
  46 {
  47     /* Returns NULL unless there is exactly one hvsd device */
  48     return HVSYNDBG(object_resolve_path_type("", TYPE_HV_SYNDBG, NULL));
  49 }
  50
  51 static void set_pending_state(HvSynDbg *syndbg, bool has_pending)
  52 {
  53     hwaddr out_len;
  54     void *out_data;
  55
  56     syndbg->has_data_pending = has_pending;
  57
  58     if (!syndbg->pending_page_gpa) {
  59         return;
  60     }
  61
  62     out_len = 1;
  63     out_data = cpu_physical_memory_map(syndbg->pending_page_gpa, &out_len, 1);
  64     if (out_data) {
  65         *(uint8_t *)out_data = !!has_pending;
  66         cpu_physical_memory_unmap(out_data, out_len, 1, out_len);
  67     }
  68 }
  69
  70 static bool get_udb_pkt_data(void *p, uint32_t len, uint32_t *data_ofs,
  71                              uint32_t *src_ip)
  72 {
  73     uint32_t offset, curr_len = len;
  74
  75     if (curr_len < sizeof(struct eth_header) ||
  76         (be16_to_cpu(PKT_GET_ETH_HDR(p)->h_proto) != ETH_P_IP)) {
  77         return false;
  78     }
  79     offset = sizeof(struct eth_header);
  80     curr_len -= sizeof(struct eth_header);
  81
  82     if (curr_len < sizeof(struct ip_header) ||
  83         PKT_GET_IP_HDR(p)->ip_p != IP_PROTO_UDP) {
  84         return false;
  85     }
  86     offset += PKT_GET_IP_HDR_LEN(p);
  87     curr_len -= PKT_GET_IP_HDR_LEN(p);
  88
  89     if (curr_len < sizeof(struct udp_header)) {
  90         return false;
  91     }
  92
  93     offset += sizeof(struct udp_header);
  94     *data_ofs = offset;
  95     *src_ip = PKT_GET_IP_HDR(p)->ip_src;
  96     return true;
  97 }
  98
  99 static uint16_t handle_send_msg(HvSynDbg *syndbg, uint64_t ingpa,
 100                                 uint32_t count, bool is_raw,
 101                                 uint32_t *pending_count)
 102 {
 103     uint16_t ret;
 104     hwaddr data_len;
 105     void *debug_data = NULL;
 106     uint32_t udp_data_ofs = 0;
 107     const void *pkt_data;
 108     int sent_count;
 109
 110     data_len = count;
 111     debug_data = cpu_physical_memory_map(ingpa, &data_len, 0);
 112     if (!debug_data || data_len < count) {
 113         ret = HV_STATUS_INSUFFICIENT_MEMORY;
 114         goto cleanup;
 115     }
 116
 117     if (is_raw &&
 118         !get_udb_pkt_data(debug_data, count, &udp_data_ofs,
 119                           &syndbg->target_ip)) {
 120         ret = HV_STATUS_SUCCESS;
 121         goto cleanup;
 122     }
 123
 124     pkt_data = (const void *)((uintptr_t)debug_data + udp_data_ofs);
 125     sent_count = sendto(syndbg->socket, pkt_data, count - udp_data_ofs,
 126                              MSG_NOSIGNAL, NULL, 0);
 127     if (sent_count == -1) {
 128         ret = HV_STATUS_INSUFFICIENT_MEMORY;
 129         goto cleanup;
 130     }
 131
 132     *pending_count = count - (sent_count + udp_data_ofs);
 133     ret = HV_STATUS_SUCCESS;
 134 cleanup:
 135     if (debug_data) {
 136         cpu_physical_memory_unmap(debug_data, count, 0, data_len);
 137     }
 138
 139     return ret;
 140 }
 141
 142 #define UDP_PKT_HEADER_SIZE \
 143     (sizeof(struct eth_header) + sizeof(struct ip_header) +\
 144      sizeof(struct udp_header))
 145
 146 static bool create_udp_pkt(HvSynDbg *syndbg, void *pkt, uint32_t pkt_len,
 147                            void *udp_data, uint32_t udp_data_len)
 148 {
 149     struct udp_header *udp_part;
 150
 151     if (pkt_len < (UDP_PKT_HEADER_SIZE + udp_data_len)) {
 152         return false;
 153     }
 154
 155     /* Setup the eth */
 156     memset(&PKT_GET_ETH_HDR(pkt)->h_source, 0, ETH_ALEN);
 157     memset(&PKT_GET_ETH_HDR(pkt)->h_dest, 0, ETH_ALEN);
 158     PKT_GET_ETH_HDR(pkt)->h_proto = cpu_to_be16(ETH_P_IP);
 159
 160     /* Setup the ip */
 161     PKT_GET_IP_HDR(pkt)->ip_ver_len =
 162         (4 << 4) | (sizeof(struct ip_header) >> 2);
 163     PKT_GET_IP_HDR(pkt)->ip_tos = 0;
 164     PKT_GET_IP_HDR(pkt)->ip_id = 0;
 165     PKT_GET_IP_HDR(pkt)->ip_off = 0;
 166     PKT_GET_IP_HDR(pkt)->ip_ttl = 64; /* IPDEFTTL */
 167     PKT_GET_IP_HDR(pkt)->ip_p = IP_PROTO_UDP;
 168     PKT_GET_IP_HDR(pkt)->ip_src = syndbg->servaddr.sin_addr.s_addr;
 169     PKT_GET_IP_HDR(pkt)->ip_dst = syndbg->target_ip;
 170     PKT_GET_IP_HDR(pkt)->ip_len =
 171         cpu_to_be16(sizeof(struct ip_header) + sizeof(struct udp_header) +
 172                     udp_data_len);
 173     eth_fix_ip4_checksum(PKT_GET_IP_HDR(pkt), PKT_GET_IP_HDR_LEN(pkt));
 174
 175     udp_part = (struct udp_header *)((uintptr_t)pkt +
 176                                      sizeof(struct eth_header) +
 177                                      PKT_GET_IP_HDR_LEN(pkt));
 178     udp_part->uh_sport = syndbg->servaddr.sin_port;
 179     udp_part->uh_dport = syndbg->servaddr.sin_port;
 180     udp_part->uh_ulen = cpu_to_be16(sizeof(struct udp_header) + udp_data_len);
 181     memcpy(udp_part + 1, udp_data, udp_data_len);
 182     net_checksum_calculate(pkt, UDP_PKT_HEADER_SIZE + udp_data_len, CSUM_ALL);
 183     return true;
 184 }
 185
 186 static uint16_t handle_recv_msg(HvSynDbg *syndbg, uint64_t outgpa,
 187                                 uint32_t count, bool is_raw, uint32_t options,
 188                                 uint64_t timeout, uint32_t *retrieved_count)
 189 {
 190     uint16_t ret;
 191     uint8_t data_buf[TARGET_PAGE_SIZE - UDP_PKT_HEADER_SIZE];
 192     hwaddr out_len;
 193     void *out_data;
 194     ssize_t recv_byte_count;
 195
 196     /* TODO: Handle options and timeout */
 197     (void)options;
 198     (void)timeout;
 199
 200     if (!syndbg->has_data_pending) {
 201         recv_byte_count = 0;
 202     } else {
 203         recv_byte_count = recv(syndbg->socket, data_buf,
 204                                MIN(sizeof(data_buf), count), MSG_WAITALL);
 205         if (recv_byte_count == -1) {
 206             return HV_STATUS_INVALID_PARAMETER;
 207         }
 208     }
 209
 210     if (!recv_byte_count) {
 211         *retrieved_count = 0;
 212         return HV_STATUS_NO_DATA;
 213     }
 214
 215     set_pending_state(syndbg, false);
 216
 217     out_len = recv_byte_count;
 218     if (is_raw) {
 219         out_len += UDP_PKT_HEADER_SIZE;
 220     }
 221     out_data = cpu_physical_memory_map(outgpa, &out_len, 1);
 222     if (!out_data) {
 223         return HV_STATUS_INSUFFICIENT_MEMORY;
 224     }
 225
 226     if (is_raw &&
 227         !create_udp_pkt(syndbg, out_data,
 228                         recv_byte_count + UDP_PKT_HEADER_SIZE,
 229                         data_buf, recv_byte_count)) {
 230         ret = HV_STATUS_INSUFFICIENT_MEMORY;
 231         goto cleanup_out_data;
 232     } else if (!is_raw) {
 233         memcpy(out_data, data_buf, recv_byte_count);
 234     }
 235
 236     *retrieved_count = recv_byte_count;
 237     if (is_raw) {
 238         *retrieved_count += UDP_PKT_HEADER_SIZE;
 239     }
 240     ret = HV_STATUS_SUCCESS;
 241
 242 cleanup_out_data:
 243     cpu_physical_memory_unmap(out_data, out_len, 1, out_len);
 244     return ret;
 245 }
 246
 247 static uint16_t hv_syndbg_handler(void *context, HvSynDbgMsg *msg)
 248 {
 249     HvSynDbg *syndbg = context;
 250     uint16_t ret = HV_STATUS_INVALID_HYPERCALL_CODE;
 251
 252     switch (msg->type) {
 253     case HV_SYNDBG_MSG_CONNECTION_INFO:
 254         msg->u.connection_info.host_ip =
 255             ntohl(syndbg->servaddr.sin_addr.s_addr);
 256         msg->u.connection_info.host_port =
 257             ntohs(syndbg->servaddr.sin_port);
 258         ret = HV_STATUS_SUCCESS;
 259         break;
 260     case HV_SYNDBG_MSG_SEND:
 261         ret = handle_send_msg(syndbg, msg->u.send.buf_gpa, msg->u.send.count,
 262                               msg->u.send.is_raw, &msg->u.send.pending_count);
 263         break;
 264     case HV_SYNDBG_MSG_RECV:
 265         ret = handle_recv_msg(syndbg, msg->u.recv.buf_gpa, msg->u.recv.count,
 266                               msg->u.recv.is_raw, msg->u.recv.options,
 267                               msg->u.recv.timeout,
 268                               &msg->u.recv.retrieved_count);
 269         break;
 270     case HV_SYNDBG_MSG_SET_PENDING_PAGE:
 271         syndbg->pending_page_gpa = msg->u.pending_page.buf_gpa;
 272         ret = HV_STATUS_SUCCESS;
 273         break;
 274     case HV_SYNDBG_MSG_QUERY_OPTIONS:
 275         msg->u.query_options.options = 0;
 276         if (syndbg->use_hcalls) {
 277             msg->u.query_options.options = HV_X64_SYNDBG_OPTION_USE_HCALLS;
 278         }
 279         ret = HV_STATUS_SUCCESS;
 280         break;
 281     default:
 282         break;
 283     }
 284
 285     return ret;
 286 }
 287
 288 static void hv_syndbg_recv_event(void *opaque)
 289 {
 290     HvSynDbg *syndbg = opaque;
 291     struct timeval tv;
 292     fd_set rfds;
 293
 294     tv.tv_sec = 0;
 295     tv.tv_usec = 0;
 296     FD_ZERO(&rfds);
 297     FD_SET(syndbg->socket, &rfds);
 298     if (select(syndbg->socket + 1, &rfds, NULL, NULL, &tv) > 0) {
 299         set_pending_state(syndbg, true);
 300     }
 301 }
 302
 303 static void hv_syndbg_realize(DeviceState *dev, Error **errp)
 304 {
 305     HvSynDbg *syndbg = HVSYNDBG(dev);
 306
 307     if (!hv_syndbg_find()) {
 308         error_setg(errp, "at most one %s device is permitted", TYPE_HV_SYNDBG);
 309         return;
 310     }
 311
 312     if (!vmbus_bridge_find()) {
 313         error_setg(errp, "%s device requires vmbus-bridge device",
 314                    TYPE_HV_SYNDBG);
 315         return;
 316     }
 317
 318     /* Parse and host_ip */
 319     if (qemu_isdigit(syndbg->host_ip[0])) {
 320         syndbg->servaddr.sin_addr.s_addr = inet_addr(syndbg->host_ip);
 321     } else {
 322         struct hostent *he = gethostbyname(syndbg->host_ip);
 323         if (!he) {
 324             error_setg(errp, "%s failed to resolve host name %s",
 325                        TYPE_HV_SYNDBG, syndbg->host_ip);
 326             return;
 327         }
 328         syndbg->servaddr.sin_addr = *(struct in_addr *)he->h_addr;
 329     }
 330
 331     syndbg->socket = socket(AF_INET, SOCK_DGRAM, 0);
 332     if (syndbg->socket < 0) {
 333         error_setg(errp, "%s failed to create socket", TYPE_HV_SYNDBG);
 334         return;
 335     }
 336
 337     qemu_socket_set_nonblock(syndbg->socket);
 338
 339     syndbg->servaddr.sin_port = htons(syndbg->host_port);
 340     syndbg->servaddr.sin_family = AF_INET;
 341     if (connect(syndbg->socket, (struct sockaddr *)&syndbg->servaddr,
 342                 sizeof(syndbg->servaddr)) < 0) {
 343         closesocket(syndbg->socket);
 344         error_setg(errp, "%s failed to connect to socket", TYPE_HV_SYNDBG);
 345         return;
 346     }
 347
 348     syndbg->pending_page_gpa = 0;
 349     syndbg->has_data_pending = false;
 350     hyperv_set_syndbg_handler(hv_syndbg_handler, syndbg);
 351     qemu_set_fd_handler(syndbg->socket, hv_syndbg_recv_event, NULL, syndbg);
 352 }
 353
 354 static void hv_syndbg_unrealize(DeviceState *dev)
 355 {
 356     HvSynDbg *syndbg = HVSYNDBG(dev);
 357
 358     if (syndbg->socket > 0) {
 359         qemu_set_fd_handler(syndbg->socket, NULL, NULL, NULL);
 360         closesocket(syndbg->socket);
 361     }
 362 }
 363
 364 static const VMStateDescription vmstate_hv_syndbg = {
 365     .name = TYPE_HV_SYNDBG,
 366     .unmigratable = 1,
 367 };
 368
 369 static Property hv_syndbg_properties[] = {
 370     DEFINE_PROP_STRING("host_ip", HvSynDbg, host_ip),
 371     DEFINE_PROP_UINT16("host_port", HvSynDbg, host_port, 50000),
 372     DEFINE_PROP_BOOL("use_hcalls", HvSynDbg, use_hcalls, false),
 373     DEFINE_PROP_END_OF_LIST(),
 374 };
 375
 376 static void hv_syndbg_class_init(ObjectClass *klass, void *data)
 377 {
 378     DeviceClass *dc = DEVICE_CLASS(klass);
 379
 380     device_class_set_props(dc, hv_syndbg_properties);
 381     dc->fw_name = TYPE_HV_SYNDBG;
 382     dc->vmsd = &vmstate_hv_syndbg;
 383     dc->realize = hv_syndbg_realize;
 384     dc->unrealize = hv_syndbg_unrealize;
 385     dc->user_creatable = true;
 386     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 387 }
 388
 389 static const TypeInfo hv_syndbg_type_info = {
 390     .name = TYPE_HV_SYNDBG,
 391     .parent = TYPE_DEVICE,
 392     .instance_size = sizeof(HvSynDbg),
 393     .class_init = hv_syndbg_class_init,
 394 };
 395
 396 static void hv_syndbg_register_types(void)
 397 {
 398     type_register_static(&hv_syndbg_type_info);
 399 }
 400
 401 type_init(hv_syndbg_register_types)