Re: [PATCH v4 01/13] libxl: add generic function to add device

[Wei Liu <wei.liu2@citrix.com>]

On Tue, Jul 18, 2017 at 05:25:18PM +0300, Oleksandr Grytsov wrote:
> From: Oleksandr Grytsov <oleksandr_grytsov@epam.com>
> 
> Add libxl__device_add to simple write XenStore device conifg
> and libxl__device_add_async to update domain configuration
> and write XenStore device config asynchroniously.
> Almost all devices have similar libxl__device_xxxx_add function.
> This generic functions implement same functionality but
> using the device handling framework. Th device specific
> part such as setting xen store configurationis moved
> to set_xenstore_config callback of the device framework.
> 

The two add functions look correct.

Some comments below.

> Signed-off-by: Oleksandr Grytsov <oleksandr_grytsov@epam.com>
> ---
>  tools/libxl/libxl_create.c   |   3 +
>  tools/libxl/libxl_device.c   | 198 +++++++++++++++++++++++++++++++++++++++++++
>  tools/libxl/libxl_disk.c     |   2 +
>  tools/libxl/libxl_internal.h |  36 ++++++++
>  tools/libxl/libxl_nic.c      |   2 +
>  tools/libxl/libxl_pci.c      |   2 +
>  tools/libxl/libxl_usb.c      |   6 ++
>  tools/libxl/libxl_vtpm.c     |   2 +
>  8 files changed, 251 insertions(+)
> 
> diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
> index bffbc45..b2163cd 100644
> --- a/tools/libxl/libxl_create.c
> +++ b/tools/libxl/libxl_create.c
> @@ -1430,6 +1430,9 @@ out:
>  
>  #define libxl_device_dtdev_list NULL
>  #define libxl_device_dtdev_compare NULL
> +#define libxl__device_from_dtdev NULL
> +#define libxl__device_dtdev_setdefault NULL
> +#define libxl__device_dtdev_update_devid NULL
>  static DEFINE_DEVICE_TYPE_STRUCT(dtdev);
>  
>  const struct libxl_device_type *device_type_tbl[] = {
> diff --git a/tools/libxl/libxl_device.c b/tools/libxl/libxl_device.c
> index 00356af..07165f0 100644
> --- a/tools/libxl/libxl_device.c
> +++ b/tools/libxl/libxl_device.c
> @@ -1793,6 +1793,204 @@ out:
>      return AO_CREATE_FAIL(rc);
>  }
>  
> +static void device_add_domain_config(libxl__gc *gc,
> +                                     libxl_domain_config *d_config,
> +                                     const struct libxl_device_type *dt,
> +                                     void *type)
> +{
> +    int *num_dev;
> +    int i;

unsigned int please.

> +    void *item = NULL;
> +
> +    num_dev = libxl__device_type_get_num(dt, d_config);
> +
> +    /* Check for existing device */
> +    for (i = 0; i < *num_dev; i++) {
> +        if (dt->compare(libxl__device_type_get_elem(dt, d_config, i), type)) {
> +            item = libxl__device_type_get_elem(dt, d_config, i);
> +        }
> +    }
> +
> +    if (!item) {
> +        void **devs= libxl__device_type_get_ptr(dt, d_config);

Space after devs.

> +        *devs = libxl__realloc(NOGC, *devs,
> +                               dt->dev_elem_size * (*num_dev + 1));
> +        item = libxl__device_type_get_elem(dt, d_config, *num_dev);
> +        (*num_dev)++;
> +    } else {
> +        dt->dispose(item);
> +    }
> +
> +    dt->init(item);
> +    dt->copy(CTX, item, type);
> +}
> +
> +void libxl__device_add_async(libxl__egc *egc, uint32_t domid,
> +                             const struct libxl_device_type *dt, void *type,
> +                             libxl__ao_device *aodev)
> +{
> +    STATE_AO_GC(aodev->ao);
> +    flexarray_t *back;
> +    flexarray_t *front, *ro_front;
> +    libxl__device *device;
> +    xs_transaction_t t = XBT_NULL;
> +    libxl_domain_config d_config;
> +    void *type_saved;
> +    libxl__domain_userdata_lock *lock = NULL;
> +    int rc;
> +
> +    libxl_domain_config_init(&d_config);
> +
> +    type_saved = libxl__malloc(gc, dt->dev_elem_size);
> +
> +    dt->init(type_saved);
> +    dt->copy(CTX, type_saved, type);
> +
> +    if (dt->set_default) {
> +        rc = dt->set_default(gc, domid, type, aodev->update_json);
> +        if (rc) goto out;
> +    }
> +
> +    if (dt->update_devid) {
> +        rc = dt->update_devid(gc, domid, type);
> +        if (rc) goto out;
> +    }
> +
> +    if (dt->update_config)
> +        dt->update_config(gc, type_saved, type);
> +
> +    GCNEW(device);
> +    rc = dt->to_device(gc, domid, type, device);
> +    if (rc) goto out;
> +
> +    if (aodev->update_json) {
> +

Extraneous empty line here.

> +        lock = libxl__lock_domain_userdata(gc, domid);
> +        if (!lock) {
> +            rc = ERROR_LOCK_FAIL;
> +            goto out;
> +        }
> +
> +        rc = libxl__get_domain_configuration(gc, domid, &d_config);
> +        if (rc) goto out;
> +
> +        device_add_domain_config(gc, &d_config, dt, type_saved);
> +
> +        rc = libxl__dm_check_start(gc, &d_config, domid);
> +        if (rc) goto out;
> +    }
> +
> +    back = flexarray_make(gc, 16, 1);
> +    front = flexarray_make(gc, 16, 1);
> +    ro_front = flexarray_make(gc, 16, 1);
> +
> +    flexarray_append_pair(back, "frontend-id", GCSPRINTF("%d", domid));
> +    flexarray_append_pair(back, "online", "1");
> +    flexarray_append_pair(back, "state",
> +                          GCSPRINTF("%d", XenbusStateInitialising));
> +
> +    flexarray_append_pair(front, "backend-id",
> +                          GCSPRINTF("%d", device->backend_domid));
> +    flexarray_append_pair(front, "state",
> +                          GCSPRINTF("%d", XenbusStateInitialising));
> +
> +    if (dt->set_xenstore_config)
> +        dt->set_xenstore_config(gc, domid, type, back, front, ro_front);
> +
> +    for (;;) {
> +        rc = libxl__xs_transaction_start(gc, &t);
> +        if (rc) goto out;
> +
> +        rc = libxl__device_exists(gc, t, device);
> +        if (rc < 0) goto out;
> +        if (rc == 1) {              /* already exists in xenstore */
> +            LOGD(ERROR, domid, "device already exists in xenstore");
> +            aodev->action = LIBXL__DEVICE_ACTION_ADD; /* for error message */
> +            rc = ERROR_DEVICE_EXISTS;
> +            goto out;
> +        }
> +
> +        if (aodev->update_json) {
> +            rc = libxl__set_domain_configuration(gc, domid, &d_config);
> +            if (rc) goto out;
> +        }
> +
> +        libxl__device_generic_add(gc, t, device,
> +                                  libxl__xs_kvs_of_flexarray(gc, back),
> +                                  libxl__xs_kvs_of_flexarray(gc, front),
> +                                  libxl__xs_kvs_of_flexarray(gc, ro_front));
> +
> +        rc = libxl__xs_transaction_commit(gc, &t);
> +        if (!rc) break;
> +        if (rc < 0) goto out;
> +    }
> +
> +    aodev->dev = device;
> +    aodev->action = LIBXL__DEVICE_ACTION_ADD;
> +    libxl__wait_device_connection(egc, aodev);
> +
> +    rc = 0;
> +
> +out:
> +    libxl__xs_transaction_abort(gc, &t);
> +    if (lock) libxl__unlock_domain_userdata(lock);
> +    dt->dispose(type_saved);
> +    libxl_domain_config_dispose(&d_config);
> +    aodev->rc = rc;
> +    if (rc) aodev->callback(egc, aodev);
> +    return;
> +}
> +
> +int libxl__device_add(libxl__gc *gc, uint32_t domid,
> +                      const struct libxl_device_type *dt, void *type)
> +{
> +    flexarray_t *back;
> +    flexarray_t *front, *ro_front;
> +    libxl__device *device;
> +    int rc;
> +
> +    if (dt->set_default) {
> +        rc = dt->set_default(gc, domid, type, false);
> +        if (rc) goto out;
> +    }
> +
> +    if (dt->update_devid) {
> +        rc = dt->update_devid(gc, domid, type);
> +        if (rc) goto out;
> +    }
> +
> +    GCNEW(device);
> +    rc = dt->to_device(gc, domid, type, device);
> +    if (rc) goto out;
> +
> +    back = flexarray_make(gc, 16, 1);
> +    front = flexarray_make(gc, 16, 1);
> +    ro_front = flexarray_make(gc, 16, 1);
> +
> +    flexarray_append_pair(back, "frontend-id", GCSPRINTF("%d", domid));
> +    flexarray_append_pair(back, "online", "1");
> +    flexarray_append_pair(back, "state",
> +                          GCSPRINTF("%d", XenbusStateInitialising));
> +    flexarray_append_pair(front, "backend-id",
> +                          libxl__sprintf(gc, "%d", device->backend_domid));
> +    flexarray_append_pair(front, "state",
> +                          GCSPRINTF("%d", XenbusStateInitialising));
> +
> +    if (dt->set_xenstore_config)
> +        dt->set_xenstore_config(gc, domid, type, back, front, ro_front);
> +
> +    rc = libxl__device_generic_add(gc, XBT_NULL, device,
> +                                   libxl__xs_kvs_of_flexarray(gc, back),
> +                                   libxl__xs_kvs_of_flexarray(gc, front),
> +                                   libxl__xs_kvs_of_flexarray(gc, ro_front));
> +    if (rc) goto out;
> +
> +    rc = 0;
> +
> +out:
> +    return rc;
> +}
> +
>  /*
>   * Local variables:
>   * mode: C
> diff --git a/tools/libxl/libxl_disk.c b/tools/libxl/libxl_disk.c
> index 63de75c..f2f3635 100644
> --- a/tools/libxl/libxl_disk.c
> +++ b/tools/libxl/libxl_disk.c
> @@ -1244,6 +1244,8 @@ static int libxl_device_disk_dm_needed(void *e, unsigned domid)
>             elem->backend_domid == domid;
>  }
>  
> +#define libxl__device_disk_update_devid NULL
> +

Is this correct for disk (and other device types as well)?

Since you've defined LIBXL_DEFINE_UPDATE_DEVID, you should be able to
use that immediately?

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