hw/xen/xen-host-pci-device.c

   1 /*
   2  * Copyright (C) 2011       Citrix Ltd.
   3  *
   4  * This work is licensed under the terms of the GNU GPL, version 2.  See
   5  * the COPYING file in the top-level directory.
   6  *
   7  */
   8
   9 #include "qemu/osdep.h"
  10 #include "qapi/error.h"
  11 #include "qemu/cutils.h"
  12 #include "hw/xen/xen-legacy-backend.h"
  13 #include "hw/xen/xen-bus-helper.h"
  14 #include "xen-host-pci-device.h"
  15
  16 #define XEN_HOST_PCI_MAX_EXT_CAP \
  17     ((PCIE_CONFIG_SPACE_SIZE - PCI_CONFIG_SPACE_SIZE) / (PCI_CAP_SIZEOF + 4))
  18
  19 #ifdef XEN_HOST_PCI_DEVICE_DEBUG
  20 #  define XEN_HOST_PCI_LOG(f, a...) fprintf(stderr, "%s: " f, __func__, ##a)
  21 #else
  22 #  define XEN_HOST_PCI_LOG(f, a...) (void)0
  23 #endif
  24
  25 /*
  26  * from linux/ioport.h
  27  * IO resources have these defined flags.
  28  */
  29 #define IORESOURCE_BITS         0x000000ff      /* Bus-specific bits */
  30
  31 #define IORESOURCE_TYPE_BITS    0x00000f00      /* Resource type */
  32 #define IORESOURCE_IO           0x00000100
  33 #define IORESOURCE_MEM          0x00000200
  34
  35 #define IORESOURCE_PREFETCH     0x00001000      /* No side effects */
  36 #define IORESOURCE_MEM_64       0x00100000
  37
  38 /*
  39  * Non-passthrough (dom0) accesses are local PCI devices and use the given BDF
  40  * Passthough (stubdom) accesses are through PV frontend PCI device.  Those
  41  * either have a BDF identical to the backend's BDF (xen-backend.passthrough=1)
  42  * or a local virtual BDF (xen-backend.passthrough=0)
  43  *
  44  * We are always given the backend's BDF and need to lookup the appropriate
  45  * local BDF for sysfs access.
  46  */
  47 static void xen_host_pci_fill_local_addr(XenHostPCIDevice *d, Error **errp)
  48 {
  49     unsigned int num_devs, len, i;
  50     unsigned int domain, bus, dev, func;
  51     char *be_path = NULL;
  52     char path[16];
  53
  54     be_path = qemu_xen_xs_read(xenstore, 0, "device/pci/0/backend", &len);
  55     if (!be_path) {
  56         error_setg(errp, "Failed to read device/pci/0/backend");
  57         goto out;
  58     }
  59
  60     if (xs_node_scanf(xenstore, 0, be_path, "num_devs", NULL,
  61                       "%d", &num_devs) != 1) {
  62         error_setg(errp, "Failed to read or parse %s/num_devs", be_path);
  63         goto out;
  64     }
  65
  66     for (i = 0; i < num_devs; i++) {
  67         snprintf(path, sizeof(path), "dev-%d", i);
  68         if (xs_node_scanf(xenstore, 0, be_path, path, NULL,
  69                           "%x:%x:%x.%x", &domain, &bus, &dev, &func) != 4) {
  70             error_setg(errp, "Failed to read or parse %s/%s", be_path, path);
  71             goto out;
  72         }
  73         if (domain != d->domain ||
  74                 bus != d->bus ||
  75                 dev != d->dev ||
  76                 func != d->func)
  77             continue;
  78         snprintf(path, sizeof(path), "vdev-%d", i);
  79         if (xs_node_scanf(xenstore, 0, be_path, path, NULL,
  80                           "%x:%x:%x.%x", &domain, &bus, &dev, &func) != 4) {
  81             error_setg(errp, "Failed to read or parse %s/%s", be_path, path);
  82             goto out;
  83         }
  84         d->local_domain = domain;
  85         d->local_bus = bus;
  86         d->local_dev = dev;
  87         d->local_func = func;
  88         goto out;
  89     }
  90     error_setg(errp, "Failed to find PCI device %x:%x:%x.%x in xenstore",
  91                d->domain, d->bus, d->dev, d->func);
  92
  93 out:
  94     free(be_path);
  95 }
  96
  97 static void xen_host_pci_sysfs_path(const XenHostPCIDevice *d,
  98                                     const char *name, char *buf, ssize_t size)
  99 {
 100     int rc;
 101
 102     rc = snprintf(buf, size, "/sys/bus/pci/devices/%04x:%02x:%02x.%d/%s",
 103                   d->local_domain, d->local_bus, d->local_dev, d->local_func,
 104                   name);
 105     assert(rc >= 0 && rc < size);
 106 }
 107
 108
 109 /* This size should be enough to read the first 7 lines of a resource file */
 110 #define XEN_HOST_PCI_RESOURCE_BUFFER_SIZE 400
 111 static void xen_host_pci_get_resource(XenHostPCIDevice *d, Error **errp)
 112 {
 113     int i, rc, fd;
 114     char path[PATH_MAX];
 115     char buf[XEN_HOST_PCI_RESOURCE_BUFFER_SIZE];
 116     unsigned long long start, end, flags, size;
 117     char *endptr, *s;
 118     uint8_t type;
 119
 120     xen_host_pci_sysfs_path(d, "resource", path, sizeof(path));
 121
 122     fd = open(path, O_RDONLY);
 123     if (fd == -1) {
 124         error_setg_file_open(errp, errno, path);
 125         return;
 126     }
 127
 128     do {
 129         rc = read(fd, &buf, sizeof(buf) - 1);
 130         if (rc < 0 && errno != EINTR) {
 131             error_setg_errno(errp, errno, "read err");
 132             goto out;
 133         }
 134     } while (rc < 0);
 135     buf[rc] = 0;
 136
 137     s = buf;
 138     for (i = 0; i < PCI_NUM_REGIONS; i++) {
 139         type = 0;
 140
 141         start = strtoll(s, &endptr, 16);
 142         if (*endptr != ' ' || s == endptr) {
 143             break;
 144         }
 145         s = endptr + 1;
 146         end = strtoll(s, &endptr, 16);
 147         if (*endptr != ' ' || s == endptr) {
 148             break;
 149         }
 150         s = endptr + 1;
 151         flags = strtoll(s, &endptr, 16);
 152         if (*endptr != '\n' || s == endptr) {
 153             break;
 154         }
 155         s = endptr + 1;
 156
 157         if (start) {
 158             size = end - start + 1;
 159         } else {
 160             size = 0;
 161         }
 162
 163         if (flags & IORESOURCE_IO) {
 164             type |= XEN_HOST_PCI_REGION_TYPE_IO;
 165         }
 166         if (flags & IORESOURCE_MEM) {
 167             type |= XEN_HOST_PCI_REGION_TYPE_MEM;
 168         }
 169         if (flags & IORESOURCE_PREFETCH) {
 170             type |= XEN_HOST_PCI_REGION_TYPE_PREFETCH;
 171         }
 172         if (flags & IORESOURCE_MEM_64) {
 173             type |= XEN_HOST_PCI_REGION_TYPE_MEM_64;
 174         }
 175
 176         if (i < PCI_ROM_SLOT) {
 177             d->io_regions[i].base_addr = start;
 178             d->io_regions[i].size = size;
 179             d->io_regions[i].type = type;
 180             d->io_regions[i].bus_flags = flags & IORESOURCE_BITS;
 181         } else {
 182             d->rom.base_addr = start;
 183             d->rom.size = size;
 184             d->rom.type = type;
 185             d->rom.bus_flags = flags & IORESOURCE_BITS;
 186         }
 187     }
 188
 189     if (i != PCI_NUM_REGIONS) {
 190         error_setg(errp, "Invalid format or input too short: %s", buf);
 191     }
 192
 193 out:
 194     close(fd);
 195 }
 196
 197 /* This size should be enough to read a long from a file */
 198 #define XEN_HOST_PCI_GET_VALUE_BUFFER_SIZE 22
 199 static void xen_host_pci_get_value(XenHostPCIDevice *d, const char *name,
 200                                    unsigned int *pvalue, int base, Error **errp)
 201 {
 202     char path[PATH_MAX];
 203     char buf[XEN_HOST_PCI_GET_VALUE_BUFFER_SIZE];
 204     int fd, rc;
 205     unsigned long value;
 206     const char *endptr;
 207
 208     xen_host_pci_sysfs_path(d, name, path, sizeof(path));
 209
 210     fd = open(path, O_RDONLY);
 211     if (fd == -1) {
 212         error_setg_file_open(errp, errno, path);
 213         return;
 214     }
 215
 216     do {
 217         rc = read(fd, &buf, sizeof(buf) - 1);
 218         if (rc < 0 && errno != EINTR) {
 219             error_setg_errno(errp, errno, "read err");
 220             goto out;
 221         }
 222     } while (rc < 0);
 223
 224     buf[rc] = 0;
 225     rc = qemu_strtoul(buf, &endptr, base, &value);
 226     if (!rc) {
 227         assert(value <= UINT_MAX);
 228         *pvalue = value;
 229     } else {
 230         error_setg_errno(errp, -rc, "failed to parse value '%s'", buf);
 231     }
 232
 233 out:
 234     close(fd);
 235 }
 236
 237 static inline void xen_host_pci_get_hex_value(XenHostPCIDevice *d,
 238                                               const char *name,
 239                                               unsigned int *pvalue,
 240                                               Error **errp)
 241 {
 242     xen_host_pci_get_value(d, name, pvalue, 16, errp);
 243 }
 244
 245 static inline void xen_host_pci_get_dec_value(XenHostPCIDevice *d,
 246                                               const char *name,
 247                                               unsigned int *pvalue,
 248                                               Error **errp)
 249 {
 250     xen_host_pci_get_value(d, name, pvalue, 10, errp);
 251 }
 252
 253 static bool xen_host_pci_dev_is_virtfn(XenHostPCIDevice *d)
 254 {
 255     char path[PATH_MAX];
 256     struct stat buf;
 257
 258     xen_host_pci_sysfs_path(d, "physfn", path, sizeof(path));
 259
 260     return !stat(path, &buf);
 261 }
 262
 263 static void xen_host_pci_config_open(XenHostPCIDevice *d, Error **errp)
 264 {
 265     char path[PATH_MAX];
 266
 267     xen_host_pci_sysfs_path(d, "config", path, sizeof(path));
 268
 269     d->config_fd = open(path, O_RDWR);
 270     if (d->config_fd == -1) {
 271         error_setg_file_open(errp, errno, path);
 272     }
 273 }
 274
 275 static int xen_host_pci_config_read(XenHostPCIDevice *d,
 276                                     int pos, void *buf, int len)
 277 {
 278     int rc;
 279
 280     do {
 281         rc = pread(d->config_fd, buf, len, pos);
 282     } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
 283     if (rc != len) {
 284         return -errno;
 285     }
 286     return 0;
 287 }
 288
 289 static int xen_host_pci_config_write(XenHostPCIDevice *d,
 290                                      int pos, const void *buf, int len)
 291 {
 292     int rc;
 293
 294     do {
 295         rc = pwrite(d->config_fd, buf, len, pos);
 296     } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
 297     if (rc != len) {
 298         return -errno;
 299     }
 300     return 0;
 301 }
 302
 303
 304 int xen_host_pci_get_byte(XenHostPCIDevice *d, int pos, uint8_t *p)
 305 {
 306     uint8_t buf;
 307     int rc = xen_host_pci_config_read(d, pos, &buf, 1);
 308     if (!rc) {
 309         *p = buf;
 310     }
 311     return rc;
 312 }
 313
 314 int xen_host_pci_get_word(XenHostPCIDevice *d, int pos, uint16_t *p)
 315 {
 316     uint16_t buf;
 317     int rc = xen_host_pci_config_read(d, pos, &buf, 2);
 318     if (!rc) {
 319         *p = le16_to_cpu(buf);
 320     }
 321     return rc;
 322 }
 323
 324 int xen_host_pci_get_long(XenHostPCIDevice *d, int pos, uint32_t *p)
 325 {
 326     uint32_t buf;
 327     int rc = xen_host_pci_config_read(d, pos, &buf, 4);
 328     if (!rc) {
 329         *p = le32_to_cpu(buf);
 330     }
 331     return rc;
 332 }
 333
 334 int xen_host_pci_get_block(XenHostPCIDevice *d, int pos, uint8_t *buf, int len)
 335 {
 336     return xen_host_pci_config_read(d, pos, buf, len);
 337 }
 338
 339 int xen_host_pci_set_byte(XenHostPCIDevice *d, int pos, uint8_t data)
 340 {
 341     return xen_host_pci_config_write(d, pos, &data, 1);
 342 }
 343
 344 int xen_host_pci_set_word(XenHostPCIDevice *d, int pos, uint16_t data)
 345 {
 346     data = cpu_to_le16(data);
 347     return xen_host_pci_config_write(d, pos, &data, 2);
 348 }
 349
 350 int xen_host_pci_set_long(XenHostPCIDevice *d, int pos, uint32_t data)
 351 {
 352     data = cpu_to_le32(data);
 353     return xen_host_pci_config_write(d, pos, &data, 4);
 354 }
 355
 356 int xen_host_pci_set_block(XenHostPCIDevice *d, int pos, uint8_t *buf, int len)
 357 {
 358     return xen_host_pci_config_write(d, pos, buf, len);
 359 }
 360
 361 int xen_host_pci_find_ext_cap_offset(XenHostPCIDevice *d, uint32_t cap)
 362 {
 363     uint32_t header = 0;
 364     int max_cap = XEN_HOST_PCI_MAX_EXT_CAP;
 365     int pos = PCI_CONFIG_SPACE_SIZE;
 366
 367     do {
 368         if (xen_host_pci_get_long(d, pos, &header)) {
 369             break;
 370         }
 371         /*
 372          * If we have no capabilities, this is indicated by cap ID,
 373          * cap version and next pointer all being 0.
 374          */
 375         if (header == 0) {
 376             break;
 377         }
 378
 379         if (PCI_EXT_CAP_ID(header) == cap) {
 380             return pos;
 381         }
 382
 383         pos = PCI_EXT_CAP_NEXT(header);
 384         if (pos < PCI_CONFIG_SPACE_SIZE) {
 385             break;
 386         }
 387
 388         max_cap--;
 389     } while (max_cap > 0);
 390
 391     return -1;
 392 }
 393
 394 void xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
 395                              uint8_t bus, uint8_t dev, uint8_t func,
 396                              Error **errp)
 397 {
 398     ERRP_GUARD();
 399     unsigned int v;
 400
 401     d->config_fd = -1;
 402     d->domain = domain;
 403     d->bus = bus;
 404     d->dev = dev;
 405     d->func = func;
 406
 407     if (xen_is_stubdomain) {
 408         xen_host_pci_fill_local_addr(d, errp);
 409         if (*errp) {
 410             goto error;
 411         }
 412     } else {
 413         d->local_domain = d->domain;
 414         d->local_bus = d->bus;
 415         d->local_dev = d->dev;
 416         d->local_func = d->func;
 417     }
 418
 419     xen_host_pci_config_open(d, errp);
 420     if (*errp) {
 421         goto error;
 422     }
 423
 424     xen_host_pci_get_resource(d, errp);
 425     if (*errp) {
 426         goto error;
 427     }
 428
 429     xen_host_pci_get_hex_value(d, "vendor", &v, errp);
 430     if (*errp) {
 431         goto error;
 432     }
 433     d->vendor_id = v;
 434
 435     xen_host_pci_get_hex_value(d, "device", &v, errp);
 436     if (*errp) {
 437         goto error;
 438     }
 439     d->device_id = v;
 440
 441     xen_host_pci_get_dec_value(d, "irq", &v, errp);
 442     if (*errp) {
 443         goto error;
 444     }
 445     d->irq = v;
 446
 447     xen_host_pci_get_hex_value(d, "class", &v, errp);
 448     if (*errp) {
 449         goto error;
 450     }
 451     d->class_code = v;
 452
 453     d->is_virtfn = xen_host_pci_dev_is_virtfn(d);
 454
 455     return;
 456
 457 error:
 458
 459     if (d->config_fd >= 0) {
 460         close(d->config_fd);
 461         d->config_fd = -1;
 462     }
 463 }
 464
 465 bool xen_host_pci_device_closed(XenHostPCIDevice *d)
 466 {
 467     return d->config_fd == -1;
 468 }
 469
 470 void xen_host_pci_device_put(XenHostPCIDevice *d)
 471 {
 472     if (d->config_fd >= 0) {
 473         close(d->config_fd);
 474         d->config_fd = -1;
 475     }
 476 }