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  • dpdk源码---vfio(zym)

    主要想找到从nvme设备 到 vfio驱动的代码路径

    [spdk/lib/nvme/nvme_pcie.c]

    nvme_pcie_ctrlr_scan(struct spdk_nvme_probe_ctx *probe_ctx,bool direct_connect) (nvme_tcp,nvme_rdma等都有自己的scan,probe等函数,统一被封装起来,如下)

    1 int nvme_transport_ctrlr_scan(struct spdk_nvme_probe_ctx *probe_ctx,
    2      bool direct_connect)
    3 {
    4  NVME_TRANSPORT_CALL(probe_ctx->trid.trtype, ctrlr_scan, (probe_ctx, direct_connect));
    5 }

     1.nvme_pcie_ctrl_scan:

     1 int
     2 nvme_pcie_ctrlr_scan(struct spdk_nvme_probe_ctx *probe_ctx,
     3              bool direct_connect)
     4 {
     5     .......//若probe_ctx中有指定nvme pci id,has_pci_addr=true
     6     if (enum_ctx.has_pci_addr == false) {
     7         return spdk_pci_enumerate(spdk_pci_nvme_get_driver(),//若没有指定
     8                       pcie_nvme_enum_cb, &enum_ctx);
     9     } else {
    10         return spdk_pci_device_attach(spdk_pci_nvme_get_driver(),//指定了话直接attach
    11                           pcie_nvme_enum_cb, &enum_ctx, &enum_ctx.pci_addr);
    12     }
    13 

     spdk_pci_enumerate:

     1 int
     2 spdk_pci_enumerate(struct spdk_pci_driver *driver,
     3            spdk_pci_enum_cb enum_cb,
     4            void *enum_ctx)
     5 {
     6     struct spdk_pci_device *dev;
     7     int rc;
     8 
     9     cleanup_pci_devices();
    10 
    11     pthread_mutex_lock(&g_pci_mutex);
    12     TAILQ_FOREACH(dev, &g_pci_devices, internal.tailq) { //遍历g_pci_devices
    13         if (dev->internal.attached ||
    14             dev->internal.driver != driver ||
    15             dev->internal.pending_removal) {
    16             continue;
    17         }
    18 
    19         rc = enum_cb(enum_ctx, dev);// 从g_pci_devices找到我们要的driver,那么调用回调函数进行后续的ctrl_construct工作
    20         if (rc == 0) {
    21             dev->internal.attached = true;//构建成功,attach设置为true
    22         } else if (rc < 0) {
    23             pthread_mutex_unlock(&g_pci_mutex);
    24             return -1;
    25         }
    26     }
    27     pthread_mutex_unlock(&g_pci_mutex);
    28 
    29     if (!driver->is_registered) {//若改driver还没注册,那么register到rte_pci_bus.driver_list
    30         driver->is_registered = true;
    31         rte_pci_register(&driver->driver);
    32     }
    33 //上面不是找到了吗,下面这些是干啥?为啥要scan和probe??上面只是放到rte_pci_bus.driver_list了,后面还需做什么?
    34     driver->cb_fn = enum_cb;
    35     driver->cb_arg = enum_ctx;
    36 
    37     if (rte_bus_scan() != 0 || rte_bus_probe() != 0) {//若bus scan和probe都不成功
    38         driver->cb_arg = NULL;
    39         driver->cb_fn = NULL;
    40         return -1;
    41     }
    42 
    43     driver->cb_arg = NULL;
    44     driver->cb_fn = NULL;
    45 
    46     cleanup_pci_devices();
    47     return 0;
    48 }

    回调函数pcie_nvme_enum_cb:

    主要是执行nvme_ctrlr_probe(&trid, enum_ctx->probe_ctx, pci_dev) 从而构建相应type的ctrl:nvme_transport_ctrlr_construct(trid, &opts, devhandle),这些不放在这里介绍,会在spdk的源码解读里面分析。

    rte_pci_register:

    1 /* register a driver */
    2 void
    3 rte_pci_register(struct rte_pci_driver *driver)
    4 {
    5     TAILQ_INSERT_TAIL(&rte_pci_bus.driver_list, driver, next);
    6     driver->bus = &rte_pci_bus;
    7 }
    //注意这个
    struct rte_pci_bus rte_pci_bus = {
     .bus = {
      .scan = rte_pci_scan,
      .probe = rte_pci_probe,
      .find_device = pci_find_device,
      .plug = pci_plug,
      .unplug = pci_unplug,
      .parse = pci_parse,
      .dma_map = pci_dma_map,
      .dma_unmap = pci_dma_unmap,
      .get_iommu_class = rte_pci_get_iommu_class,
      .dev_iterate = rte_pci_dev_iterate,
      .hot_unplug_handler = pci_hot_unplug_handler,
      .sigbus_handler = pci_sigbus_handler,
     },
     .device_list = TAILQ_HEAD_INITIALIZER(rte_pci_bus.device_list),
     .driver_list = TAILQ_HEAD_INITIALIZER(rte_pci_bus.driver_list),
    };

    rte_bus_scan()和rte_bus_probe() 对所有bus进行scan和probe,若是pci_bus,执行的是上面注册的  

    .scan = rte_pci_scan,
      .probe = rte_pci_probe,

    回到 1 中的attach函数:

    spdk_pci_device_attach:跟原来看的有些不一样,之前看的版本直接调用的是rte_pci_scan

     1 int
     2 spdk_pci_device_attach(struct spdk_pci_driver *driver,
     3                spdk_pci_enum_cb enum_cb,
     4                void *enum_ctx, struct spdk_pci_addr *pci_address)
     5 {
     6     struct spdk_pci_device *dev;
     7     int rc;
     8     char bdf[32];
     9 
    10     spdk_pci_addr_fmt(bdf, sizeof(bdf), pci_address);
    11 
    12     cleanup_pci_devices();
    13 
    14     TAILQ_FOREACH(dev, &g_pci_devices, internal.tailq) {
    15         if (spdk_pci_addr_compare(&dev->addr, pci_address) == 0) {
    16             break;
    17         }
    18     }
    19 
    20     if (dev != NULL && dev->internal.driver == driver) {
    21         pthread_mutex_lock(&g_pci_mutex);
    22         if (dev->internal.attached || dev->internal.pending_removal) {
    23             pthread_mutex_unlock(&g_pci_mutex);
    24             return -1;
    25         }
    26 
    27         rc = enum_cb(enum_ctx, dev);//执行construct ctrl等
    28         if (rc == 0) {
    29             dev->internal.attached = true;
    30         }
    31         pthread_mutex_unlock(&g_pci_mutex);
    32         return rc;
    33     }
    34 
    35     if (!driver->is_registered) {
    36         driver->is_registered = true;
    37         rte_pci_register(&driver->driver);//register到rte_pci_bus.driver_list
    38     }
    39 
    40     driver->cb_fn = enum_cb;
    41     driver->cb_arg = enum_ctx;
    42 
    43 #if RTE_VERSION >= RTE_VERSION_NUM(18, 11, 0, 0)
    44     int i = 0;
    45 
    46     do {
    47         rc = rte_eal_hotplug_add("pci", bdf, "");
    48     } while (rc == -ENOMSG && ++i <= DPDK_HOTPLUG_RETRY_COUNT);
    49 
    50     if (i > 1 && rc == -EEXIST) {
    51         /* Even though the previous request timed out, the device
    52          * was attached successfully.
    53          */
    54         rc = 0;
    55     }
    56 #else
    57     rc = rte_eal_dev_attach(bdf, "");//这个函数在旧版本的dpdk中
    58 #endif
    59 
    60     driver->cb_arg = NULL;
    61     driver->cb_fn = NULL;
    62 
    63     cleanup_pci_devices();
    64     return rc == 0 ? 0 : -1;
    65 }

     rte_eal_hotplug_add:

    --------rte_dev_probe(devargs)

     1 int
     2 rte_dev_probe(const char *devargs)
     3 {
     4     struct eal_dev_mp_req req;
     5     struct rte_device *dev;
     6     int ret;
     7 
     8     memset(&req, 0, sizeof(req));
     9     req.t = EAL_DEV_REQ_TYPE_ATTACH;
    10     strlcpy(req.devargs, devargs, EAL_DEV_MP_DEV_ARGS_MAX_LEN);
    11 
    12     if (rte_eal_process_type() != RTE_PROC_PRIMARY) {//不是primary进程
    13         /**
    14          * If in secondary process, just send IPC request to
    15          * primary process.
    16          */
    17         ret = eal_dev_hotplug_request_to_primary(&req);//那么给primary进程发attch的请求
    18         if (ret != 0) {
    19             RTE_LOG(ERR, EAL,
    20                 "Failed to send hotplug request to primary
    ");
    21             return -ENOMSG;
    22         }
    23         if (req.result != 0)
    24             RTE_LOG(ERR, EAL,
    25                 "Failed to hotplug add device
    ");
    26         return req.result;
    27     }
    28 
    29     /* attach a shared device from primary start from here: */
    31     /* primary attach the new device itself. */
    32     ret = local_dev_probe(devargs, &dev);//其中会执行da->bus->scan()
    33 
    34     if (ret != 0) {
    35         RTE_LOG(ERR, EAL,
    36             "Failed to attach device on primary process
    ");
    37 
    38         /**
    39          * it is possible that secondary process failed to attached a
    40          * device that primary process have during initialization,
    41          * so for -EEXIST case, we still need to sync with secondary
    42          * process.
    43          */
    44         if (ret != -EEXIST)
    45             return ret;
    46     }
    47 
    48     /* primary send attach sync request to secondary. */
    49     ret = eal_dev_hotplug_request_to_secondary(&req);//给secondary进程发消息同步attach情况
    50 
    51     /* if any communication error, we need to rollback. */
    52     if (ret != 0) {
    53         RTE_LOG(ERR, EAL,
    54             "Failed to send hotplug add request to secondary
    ");
    55         ret = -ENOMSG;
    56         goto rollback;
    57     }
    59     /**
    60      * if any secondary failed to attach, we need to consider if rollback
    61      * is necessary.
    62      */
    63     if (req.result != 0) {
    64         RTE_LOG(ERR, EAL,
    65             "Failed to attach device on secondary process
    ");
    66         ret = req.result;
    67 
    68         /* for -EEXIST, we don't need to rollback. */
    69         if (ret == -EEXIST)
    70             return ret;
    71         goto rollback;
    72     }
    73 
    74     return 0;
    75 
    76 rollback:
    77     req.t = EAL_DEV_REQ_TYPE_ATTACH_ROLLBACK;
    78 
    79     /* primary send rollback request to secondary. */
    80     if (eal_dev_hotplug_request_to_secondary(&req) != 0)
    81         RTE_LOG(WARNING, EAL,
    82             "Failed to rollback device attach on secondary."
    83             "Devices in secondary may not sync with primary
    ");
    84 
    85     /* primary rollback itself. */
    86     if (local_dev_remove(dev) != 0)
    87         RTE_LOG(WARNING, EAL,
    88             "Failed to rollback device attach on primary."
    89             "Devices in secondary may not sync with primary
    ");
    90 
    91     return ret;
    92 }

    local_dev_probe:

    最终也是调用rte_pci_scan和pci_probe_all_drivers

     1 /* probe device at local process. */
     2 int
     3 local_dev_probe(const char *devargs, struct rte_device **new_dev)
     4 {
     5     struct rte_device *dev;
     6     struct rte_devargs *da;
     7     int ret;
     8 
     9     *new_dev = NULL;
    10     da = calloc(1, sizeof(*da));
    11     if (da == NULL)
    12         return -ENOMEM;
    13 
    14     ret = rte_devargs_parse(da, devargs);
    15     if (ret)
    16         goto err_devarg;
    17 
    18     if (da->bus->plug == NULL) {
    19         RTE_LOG(ERR, EAL, "Function plug not supported by bus (%s)
    ",
    20             da->bus->name);
    21         ret = -ENOTSUP;
    22         goto err_devarg;
    23     }
    24 
    25     ret = rte_devargs_insert(&da);
    26     if (ret)
    27         goto err_devarg;
    28 
    29     /* the rte_devargs will be referenced in the matching rte_device */
    30     ret = da->bus->scan();//pci的话执行register函数中注册的rte_pci_scan
    31     if (ret)
    32         goto err_devarg;
    33 
    34     dev = da->bus->find_device(NULL, cmp_dev_name, da->name);
    35     if (dev == NULL) {
    36         RTE_LOG(ERR, EAL, "Cannot find device (%s)
    ",
    37             da->name);
    38         ret = -ENODEV;
    39         goto err_devarg;
    40     }
    41     /* Since there is a matching device, it is now its responsibility
    42      * to manage the devargs we've just inserted. From this point
    43      * those devargs shouldn't be removed manually anymore.
    44      */
    45 
    46     ret = dev->bus->plug(dev);//rte_pci_plug中执行的是pci_probe_all_drivers(RTE_DEV_TO_PCI(dev))
    47     if (ret > 0)
    48         ret = -ENOTSUP;
    49 
    50     if (ret && !rte_dev_is_probed(dev)) { /* if hasn't ever succeeded */
    51         RTE_LOG(ERR, EAL, "Driver cannot attach the device (%s)
    ",
    52             dev->name);
    53         return ret;
    54     }
    55 
    56     *new_dev = dev;
    57     return ret;
    58 
    59 err_devarg:
    60     if (rte_devargs_remove(da) != 0) {
    61         free(da->args);
    62         free(da);
    63     }
    64     return ret;
    65 }

    所以 1 中 nvme_pcie_ctrl_scan 不管是spdk_pci_enumerate还是spdk_pci_device_attach,核心的流程都是一样的:

    执行回调函数pcie_nvme_enum_cb;

    rte_pci_scan

    rte_pci_probe/pci_probe_all_drivers  (rte_pci_probe也是调用pci_probe_all_drivers)

    所以后面我们看 rte_pci_bus.scan(rte_pci_scan)和rte_pci_bus.probe(rte_pci_probe)的实现。

    rte_pci_scan:

     1 /*
     2  * Scan the content of the PCI bus, and the devices in the devices
     3  * list
     4  */
     5 int
     6 rte_pci_scan(void)
     7 {
     8     struct dirent *e;
     9     DIR *dir;
    10     char dirname[PATH_MAX];
    11     struct rte_pci_addr addr;
    12     
    13         ........
    14     dir = opendir(rte_pci_get_sysfs_path()); ///sys/bus/pci/devices
    15     
    16         ........
    17     while ((e = readdir(dir)) != NULL) {
    18         if (e->d_name[0] == '.')
    19             continue;
    20 
    21         if (parse_pci_addr_format(e->d_name, sizeof(e->d_name), &addr) != 0)
    22             continue;
    23 
    24         snprintf(dirname, sizeof(dirname), "%s/%s",
    25                 rte_pci_get_sysfs_path(), e->d_name);
    26 
    27         if (pci_scan_one(dirname, &addr) < 0)//扫描/sys/bus/pci/devices下面每个目录
    28             goto error;
    29     }
    30     closedir(dir);
    31     return 0;
    32 ..........
    33 }

     ls /sys/bus/pci/devices/
    0000:00:00.0  0000:00:04.4  0000:00:1c.6  0000:03:00.0  0000:ff:0d.1  0000:ff:12.2  0000:ff:14.5  0000:ff:17.6
    0000:00:01.0  0000:00:04.5  0000:00:1c.7  0000:05:00.0  0000:ff:0f.0  0000:ff:12.4  0000:ff:14.6  0000:ff:17.7

      1 /* Scan one pci sysfs entry, and fill the devices list from it. */
      2 static int
      3 pci_scan_one(const char *dirname, const struct rte_pci_addr *addr)
      4 {
      5     char filename[PATH_MAX];
      6     unsigned long tmp;
      7     struct rte_pci_device *dev;
      8     char driver[PATH_MAX];
      9     int ret;
     10 
     11     dev = malloc(sizeof(*dev));
     12     if (dev == NULL)
     13         return -1;
     14 
     15     memset(dev, 0, sizeof(*dev));
     16     dev->device.bus = &rte_pci_bus.bus;
     17     dev->addr = *addr;
     18 
     19     /* get vendor id */
     20     snprintf(filename, sizeof(filename), "%s/vendor", dirname);
     21     if (eal_parse_sysfs_value(filename, &tmp) < 0) {
     22         free(dev);
     23         return -1;
     24     }
     25     dev->id.vendor_id = (uint16_t)tmp;
     26 
     27     /* get device id */
     28     snprintf(filename, sizeof(filename), "%s/device", dirname);
     29     if (eal_parse_sysfs_value(filename, &tmp) < 0) {
     30         free(dev);
     31         return -1;
     32     }
     33     dev->id.device_id = (uint16_t)tmp;
     34 
     35     /* get subsystem_vendor id */
     36     snprintf(filename, sizeof(filename), "%s/subsystem_vendor",
     37          dirname);
     38     if (eal_parse_sysfs_value(filename, &tmp) < 0) {
     39         free(dev);
     40         return -1;
     41     }
     42     dev->id.subsystem_vendor_id = (uint16_t)tmp;
     43 
     44     /* get subsystem_device id */
     45     snprintf(filename, sizeof(filename), "%s/subsystem_device",
     46          dirname);
     47     if (eal_parse_sysfs_value(filename, &tmp) < 0) {
     48         free(dev);
     49         return -1;
     50     }
     51     dev->id.subsystem_device_id = (uint16_t)tmp;
     52 
     53     /* get class_id */
     54     snprintf(filename, sizeof(filename), "%s/class",
     55          dirname);
     56     if (eal_parse_sysfs_value(filename, &tmp) < 0) {
     57         free(dev);
     58         return -1;
     59     }
     60     /* the least 24 bits are valid: class, subclass, program interface */
     61     dev->id.class_id = (uint32_t)tmp & RTE_CLASS_ANY_ID;
     62 
     63     /* get max_vfs */
     64     dev->max_vfs = 0;
     65     snprintf(filename, sizeof(filename), "%s/max_vfs", dirname);
     66     if (!access(filename, F_OK) &&
     67         eal_parse_sysfs_value(filename, &tmp) == 0)
     68         dev->max_vfs = (uint16_t)tmp;
     69     else {
     70         /* for non igb_uio driver, need kernel version >= 3.8 */
     71         snprintf(filename, sizeof(filename),
     72              "%s/sriov_numvfs", dirname);
     73         if (!access(filename, F_OK) &&
     74             eal_parse_sysfs_value(filename, &tmp) == 0)
     75             dev->max_vfs = (uint16_t)tmp;
     76     }
     77 
     78     /* get numa node, default to 0 if not present */
     79     snprintf(filename, sizeof(filename), "%s/numa_node",
     80          dirname);
     81 
     82     if (access(filename, F_OK) != -1) {
     83         if (eal_parse_sysfs_value(filename, &tmp) == 0)
     84             dev->device.numa_node = tmp;
     85         else
     86             dev->device.numa_node = -1;
     87     } else {
     88         dev->device.numa_node = 0;
     89     }
     90 
     91     pci_name_set(dev);
     92 
     93     /* parse resources */
     94     snprintf(filename, sizeof(filename), "%s/resource", dirname);
     95     if (pci_parse_sysfs_resource(filename, dev) < 0) {
     96         RTE_LOG(ERR, EAL, "%s(): cannot parse resource
    ", __func__);
     97         free(dev);
     98         return -1;
     99     }
    100 
    101     /* parse driver */
    102     snprintf(filename, sizeof(filename), "%s/driver", dirname);///sys/bus/pci/drivers
    103     ret = pci_get_kernel_driver_by_path(filename, driver, sizeof(driver));
    104     if (ret < 0) {
    105         RTE_LOG(ERR, EAL, "Fail to get kernel driver
    ");
    106         free(dev);
    107         return -1;
    108     }
    109 
    110     if (!ret) {
    111         if (!strcmp(driver, "vfio-pci"))
    112             dev->kdrv = RTE_KDRV_VFIO;
    113         else if (!strcmp(driver, "igb_uio"))
    114             dev->kdrv = RTE_KDRV_IGB_UIO;
    115         else if (!strcmp(driver, "uio_pci_generic"))
    116             dev->kdrv = RTE_KDRV_UIO_GENERIC;
    117         else
    118             dev->kdrv = RTE_KDRV_UNKNOWN;
    119     } else
    120         dev->kdrv = RTE_KDRV_NONE;
    121 
    122     /* device is valid, add in list (sorted) */
    123     if (TAILQ_EMPTY(&rte_pci_bus.device_list)) {
    124         rte_pci_add_device(dev);
    125     } else {
    126         struct rte_pci_device *dev2;
    127         int ret;
    128 
    129         TAILQ_FOREACH(dev2, &rte_pci_bus.device_list, next) {
    130             ret = rte_pci_addr_cmp(&dev->addr, &dev2->addr);
    131             if (ret > 0)
    132                 continue;
    133 
    134             if (ret < 0) {
    135                 rte_pci_insert_device(dev2, dev);
    136             } else { /* already registered */
    137                 if (!rte_dev_is_probed(&dev2->device)) {
    138                     dev2->kdrv = dev->kdrv;
    139                     dev2->max_vfs = dev->max_vfs;
    140                     pci_name_set(dev2);
    141                     memmove(dev2->mem_resource,
    142                         dev->mem_resource,
    143                         sizeof(dev->mem_resource));
    144                 } else {
    145                     /**
    146                      * If device is plugged and driver is
    147                      * probed already, (This happens when
    148                      * we call rte_dev_probe which will
    149                      * scan all device on the bus) we don't
    150                      * need to do anything here unless...
    151                      **/
    152                     if (dev2->kdrv != dev->kdrv ||
    153                         dev2->max_vfs != dev->max_vfs)
    154                         /*
    155                          * This should not happens.
    156                          * But it is still possible if
    157                          * we unbind a device from
    158                          * vfio or uio before hotplug
    159                          * remove and rebind it with
    160                          * a different configure.
    161                          * So we just print out the
    162                          * error as an alarm.
    163                          */
    164                         RTE_LOG(ERR, EAL, "Unexpected device scan at %s!
    ",
    165                             filename);
    166                 }
    167                 free(dev);
    168             }
    169             return 0;
    170         }
    171 
    172         rte_pci_add_device(dev);
    173     }
    174 
    175     return 0;
    176 }

    rte_pci_probe:

    ------FOREACH_DEVICE_ON_PCIBUS(dev)  pci_probe_all_drivers(dev)

    ------------FOREACH_DRIVER_ON_PCIBUS(dr)  rte_pci_probe_one_driver(dr, dev)

      1 /*
      2  * If vendor/device ID match, call the probe() function of the
      3  * driver.
      4  */
      5 static int
      6 rte_pci_probe_one_driver(struct rte_pci_driver *dr,
      7              struct rte_pci_device *dev)
      8 {
      9     int ret;
     10     bool already_probed;
     11     struct rte_pci_addr *loc;
     12 
     13     if ((dr == NULL) || (dev == NULL))
     14         return -EINVAL;
     15 
     16     loc = &dev->addr;
     17 
     18     /* The device is not blacklisted; Check if driver supports it */
     19     if (!rte_pci_match(dr, dev))
     20         /* Match of device and driver failed */
     21         return 1;
     22 
     23     RTE_LOG(INFO, EAL, "PCI device "PCI_PRI_FMT" on NUMA socket %i
    ",
     24             loc->domain, loc->bus, loc->devid, loc->function,
     25             dev->device.numa_node);
     26 
     27     /* no initialization when blacklisted, return without error */
     28     if (dev->device.devargs != NULL &&
     29         dev->device.devargs->policy ==
     30             RTE_DEV_BLACKLISTED) {
     31         RTE_LOG(INFO, EAL, "  Device is blacklisted, not"
     32             " initializing
    ");
     33         return 1;
     34     }
     35 
     36     if (dev->device.numa_node < 0) {
     37         RTE_LOG(WARNING, EAL, "  Invalid NUMA socket, default to 0
    ");
     38         dev->device.numa_node = 0;
     39     }
     40 
     41     already_probed = rte_dev_is_probed(&dev->device);
     42     if (already_probed && !(dr->drv_flags & RTE_PCI_DRV_PROBE_AGAIN)) {
     43         RTE_LOG(DEBUG, EAL, "Device %s is already probed
    ",
     44                 dev->device.name);
     45         return -EEXIST;
     46     }
     47 
     48     RTE_LOG(INFO, EAL, "  probe driver: %x:%x %s
    ", dev->id.vendor_id,
     49         dev->id.device_id, dr->driver.name);
     50 
     51     /*
     52      * reference driver structure
     53      * This needs to be before rte_pci_map_device(), as it enables to use
     54      * driver flags for adjusting configuration.
     55      */
     56     if (!already_probed) {
     57         enum rte_iova_mode dev_iova_mode;
     58         enum rte_iova_mode iova_mode;
     59 
     60         dev_iova_mode = pci_device_iova_mode(dr, dev);//从设备绑定的驱动判断dev_iova_mode,例如若是UIO驱动,则这里是PA
     61         iova_mode = rte_eal_iova_mode();//dpdk初始化过程判断的,首先会去判断设备的驱动,如果驱动还没注册,那么里面是根据机器上是否有iommu等判断。而spdk中nvme
    驱动是在dpdk初始化之后才注册进去的,所以即使是用uio驱动,dpdk给出的iova_mode也是VA,所以这里有点小问题!
    62 if (dev_iova_mode != RTE_IOVA_DC && 63 dev_iova_mode != iova_mode) { 64 RTE_LOG(ERR, EAL, " Expecting '%s' IOVA mode but current mode is '%s', not initializing ", 65 dev_iova_mode == RTE_IOVA_PA ? "PA" : "VA", 66 iova_mode == RTE_IOVA_PA ? "PA" : "VA"); 67 return -EINVAL; 68 } 69 70 dev->driver = dr; 71 } 72 73 if (!already_probed && (dr->drv_flags & RTE_PCI_DRV_NEED_MAPPING)) { 74 /* map resources for devices that use igb_uio */???注释有问题?? 75 ret = rte_pci_map_device(dev); 76 if (ret != 0) { 77 dev->driver = NULL; 78 return ret; 79 } 80 } 81 82 /* call the driver probe() function */ 83 ret = dr->probe(dr, dev); //在哪里????? 84 if (already_probed) 85 return ret; /* no rollback if already succeeded earlier */ 86 if (ret) { 87 dev->driver = NULL; 88 if ((dr->drv_flags & RTE_PCI_DRV_NEED_MAPPING) && 89 /* Don't unmap if device is unsupported and 90 * driver needs mapped resources. 91 */ 92 !(ret > 0 && 93 (dr->drv_flags & RTE_PCI_DRV_KEEP_MAPPED_RES))) 94 rte_pci_unmap_device(dev); 95 } else { 96 dev->device.driver = &dr->driver; 97 } 98 99 return ret; 100 }

    rte_pci_map_device 从这遍开始和vfio,uio等相关

     1 /* Map pci device */
     2 int
     3 rte_pci_map_device(struct rte_pci_device *dev)
     4 {
     5     int ret = -1;
     6 
     7     /* try mapping the NIC resources using VFIO if it exists */
     8     switch (dev->kdrv) {
     9     case RTE_KDRV_VFIO:
    10 #ifdef VFIO_PRESENT
    11         if (pci_vfio_is_enabled())
    12             ret = pci_vfio_map_resource(dev);
    13 #endif
    14         break;
    15     case RTE_KDRV_IGB_UIO:
    16     case RTE_KDRV_UIO_GENERIC:
    17         if (rte_eal_using_phys_addrs()) {
    18             /* map resources for devices that use uio */
    19             ret = pci_uio_map_resource(dev);
    20         }
    21         break;
    22     default:
    23         RTE_LOG(DEBUG, EAL,
    24             "  Not managed by a supported kernel driver, skipped
    ");
    25         ret = 1;
    26         break;
    27     }
    28 
    29     return ret;
    30 }

     pci_vfio_map_resource:

    ---1---pci_vfio_map_resource_primary 若设primary进程

    ------pci_vfio_map_resource_secondary

    -------2---------rte_vfio_setup_device

    ------------3------------vfio_mem_event_callback

    这三个函数要重点看。。。。

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  • 原文地址:https://www.cnblogs.com/yi-mu-xi/p/12441357.html
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