Re: [PATCH V3 3/6] libxl: add pvusb API

[Juergen Gross <jgross@suse.com>]

On 04/19/2015 05:50 AM, Chunyan Liu wrote:
> Add pvusb APIs, including:
>   - attach/detach (create/destroy) virtual usb controller.
>   - attach/detach usb device
>   - list usb controller and usb devices
>   - some other helper functions
>
> Signed-off-by: Chunyan Liu <cyliu@suse.com>
> Signed-off-by: Simon Cao <caobosimon@gmail.com>
> ---
> Changes to v2:
>    * remove qemu emulated usb related definitions, keep the work pure pvusb.
>      In last patch, will do all refactor work to unify pvusb and qemu emulated
>      usb.
>    * use bus.addr as user interface instead of busid to do usb-attach|detach
>    * remove usb-assignable-list APIs and some other unnecessary APIs
>    * reuse libxl_read_file_contents function instead of another new function
>      to handle getting sysfs file content
>    * fix build on different platforms as pci does
>    * fix many coding style problems
>    * address other comments in last version
>    * adjust codes to let it look better
>
>   tools/libxl/Makefile                 |    2 +-
>   tools/libxl/libxl.c                  |    2 +
>   tools/libxl/libxl.h                  |   45 ++
>   tools/libxl/libxl_internal.h         |   11 +-
>   tools/libxl/libxl_osdeps.h           |   13 +
>   tools/libxl/libxl_pvusb.c            | 1201 ++++++++++++++++++++++++++++++++++
>   tools/libxl/libxl_types.idl          |   41 ++
>   tools/libxl/libxl_types_internal.idl |    1 +
>   8 files changed, 1314 insertions(+), 2 deletions(-)
>   create mode 100644 tools/libxl/libxl_pvusb.c
>
...
> diff --git a/tools/libxl/libxl_pvusb.c b/tools/libxl/libxl_pvusb.c
> new file mode 100644
> index 0000000..4e4975a
> --- /dev/null
> +++ b/tools/libxl/libxl_pvusb.c
...
> +static int libxl__usbctrl_add_xenstore(libxl__gc *gc, uint32_t domid,
> +                                       libxl_device_usbctrl *usbctrl)
> +{
> +    flexarray_t *front;
> +    flexarray_t *back;
> +    libxl__device *device;
> +    xs_transaction_t t = XBT_NULL;
> +    int rc = 0;
> +    libxl_domain_config d_config;
> +    libxl_device_usbctrl usbctrl_saved;
> +    libxl__domain_userdata_lock *lock = NULL;
> +
> +    libxl_domain_config_init(&d_config);
> +    libxl_device_usbctrl_init(&usbctrl_saved);
> +    libxl_device_usbctrl_copy(CTX, &usbctrl_saved, usbctrl);
> +
> +    GCNEW(device);
> +    libxl__device_from_usbctrl(gc, domid, usbctrl, device);
> +
> +    front = flexarray_make(gc, 4, 1);
> +    back = flexarray_make(gc, 12, 1);
> +
> +    flexarray_append_pair(back, "frontend-id", GCSPRINTF("%d", domid));
> +    flexarray_append_pair(back, "online", "1");
> +    flexarray_append_pair(back, "state", "1");
> +    flexarray_append_pair(back, "usb-ver", GCSPRINTF("%d", usbctrl->version));
> +    flexarray_append_pair(back, "num-ports", GCSPRINTF("%d", usbctrl->ports));
> +    flexarray_append_pair(front, "backend-id", GCSPRINTF("%d", usbctrl->backend_domid));
> +    flexarray_append_pair(front, "state", "1");
> +
> +    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(usbctrl, usbctrls, domid, &usbctrl_saved, COMPARE_USBCTRL, &d_config);
> +
> +    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 */
> +            LOG(ERROR, "device already exists in xenstore");
> +            rc = ERROR_DEVICE_EXISTS;
> +            goto out;
> +        }
> +
> +        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,
> +                                                             back->count),
> +                                  libxl__xs_kvs_of_flexarray(gc, front,
> +                                                             front->count),
> +                                  NULL);
> +        libxl__usbport_add_xenstore(gc, t, domid, usbctrl);

Still no rc check.

> +        rc = libxl__xs_transaction_commit(gc, &t);
> +        if (!rc) break;
> +        if (rc < 0) goto out;
> +    }
> +
> +out:
> +    if (lock) libxl__unlock_domain_userdata(lock);
> +    libxl_device_usbctrl_dispose(&usbctrl_saved);
> +    libxl_domain_config_dispose(&d_config);
> +    return rc;
> +}
...
> +static int
> +libxl__device_usbctrl_remove_common(libxl_ctx *ctx, uint32_t domid,
> +                                    libxl_device_usbctrl *usbctrl,
> +                                    const libxl_asyncop_how *ao_how,
> +                                    int force)
> +{
> +    AO_CREATE(ctx, domid, ao_how);
> +    libxl__device *device;
> +    libxl__ao_device *aodev;
> +    libxl_device_usbctrl *usbctrls = NULL;
> +    libxl_device_usbctrl *usbctrl_find = NULL;
> +    int numctrl = 0;
> +    libxl_device_usb *usbs = NULL;
> +    int numusb = 0;
> +    int i, rc;
> +
> +    assert(usbctrl->devid != -1);
> +
> +    usbctrls = libxl_device_usbctrl_list(ctx, domid, &numctrl);
> +    if (!numctrl) {
> +        LOG(ERROR, "No USB controller exists in this domain");
> +        rc = ERROR_FAIL;
> +        goto out;
> +    }
> +
> +    for (i = 0; i < numctrl; i++) {
> +        if (usbctrl->devid == usbctrls[i].devid) {
> +            usbctrl_find = usbctrls + i;
> +            break;
> +        }
> +    }
> +
> +    if (!usbctrl_find) {
> +        LOG(ERROR, "USB controller %d is not attached to this domain",
> +            usbctrl->devid);
> +        rc = ERROR_FAIL;
> +        goto out;
> +    }
> +
> +    usbctrl = usbctrl_find;
> +
> +    GCNEW(device);
> +    libxl__device_from_usbctrl(gc, domid, usbctrl, device);
> +
> +    /* Remove usb devives first */
> +    rc  = libxl__device_usb_list(gc, domid, usbctrl->devid, &usbs, &numusb);
> +    if (rc) goto out;
> +    for (i = 0; i < numusb; i++) {
> +        if (do_usb_remove(gc, domid, &usbs[i])) {
> +            LOG(ERROR, "do_usb_remove failed");
> +            rc = ERROR_FAIL;
> +            goto out;
> +        }
> +    }
> +    /* remove usbctrl */
> +    GCNEW(aodev);
> +    libxl__prepare_ao_device(ao, aodev);
> +    aodev->action = LIBXL__DEVICE_ACTION_REMOVE;
> +    aodev->dev = device;
> +    aodev->callback = device_addrm_aocomplete;
> +    aodev->force = force;
> +    libxl__initiate_device_remove(egc, aodev);
> +
> +out:
> +    free(usbctrls);
> +    free(usbs);
> +    if(rc) return AO_ABORT(rc);

Coding style.

> +    return AO_INPROGRESS;
> +}
...
> +libxl_device_usbctrl *
> +libxl_device_usbctrl_list(libxl_ctx *ctx, uint32_t domid, int *num)
> +{
> +    GC_INIT(ctx);
> +    libxl_device_usbctrl *usbctrls = NULL;
> +    char *fe_path = NULL;
> +    char **dir = NULL;
> +    unsigned int ndirs = 0;
> +
> +    *num = 0;
> +
> +    fe_path = GCSPRINTF("%s/device/vusb",
> +                        libxl__xs_get_dompath(gc, domid));
> +    dir = libxl__xs_directory(gc, XBT_NULL, fe_path, &ndirs);
> +
> +    if (dir && ndirs) {
> +        usbctrls = malloc(sizeof(*usbctrls) * ndirs);
> +        libxl_device_usbctrl* usbctrl;
> +        libxl_device_usbctrl* end = usbctrls + ndirs;
> +        for(usbctrl = usbctrls; usbctrl < end; usbctrl++, dir++, (*num)++) {

Coding style.

> +            char *tmp;
> +            const char *be_path = libxl__xs_read(gc, XBT_NULL,
> +                                    GCSPRINTF("%s/%s/backend", fe_path, *dir));
> +
> +            libxl_device_usbctrl_init(usbctrl);
> +            usbctrl->devid = atoi(*dir);
> +
> +            tmp = libxl__xs_read(gc, XBT_NULL,
> +                                 GCSPRINTF("%s/%s/backend-id", fe_path, *dir));
> +            if (!tmp) goto outerr;
> +            usbctrl->backend_domid = atoi(tmp);
> +
> +            tmp = libxl__xs_read(gc, XBT_NULL,
> +                                 GCSPRINTF("%s/usb-ver", be_path));
> +            if (!tmp) goto outerr;
> +            usbctrl->version = atoi(tmp);
> +
> +            tmp = libxl__xs_read(gc, XBT_NULL,
> +                                 GCSPRINTF("%s/num-ports", be_path));
> +            if (!tmp) goto outerr;
> +            usbctrl->ports = atoi(tmp);
> +       }
> +    }
> +
> +    return usbctrls;
> +
> +outerr:
> +    LOG(ERROR, "Unable to list USB Controllers");
> +    for (int i = 0; i < *num; i++) {
> +        libxl_device_usbctrl_dispose(usbctrls + i);
> +    }
> +    free(usbctrls);
> +    *num = 0;
> +    return NULL;
> +}
...
> +/* get all usb devices of the domain */
> +static libxl_device_usb *
> +libxl_device_usb_list_all(libxl__gc *gc, uint32_t domid, int *num)
> +{
> +    char **usbctrls;
> +    unsigned int nd, i, j;
> +    char *be_path;
> +    int rc;
> +    libxl_device_usb *usbs = NULL;
> +
> +    *num = 0;
> +
> +    be_path = GCSPRINTF("/local/domain/%d/backend/vusb/%d",
> +                        LIBXL_TOOLSTACK_DOMID, domid);
> +    usbctrls = libxl__xs_directory(gc, XBT_NULL, be_path, &nd);
> +
> +    for (i = 0; i < nd; i++) {
> +        int nc = 0;
> +        libxl_device_usb *tmp = NULL;
> +        rc = libxl__device_usb_list(gc, domid, atoi(usbctrls[i]), &tmp, &nc);
> +        if (!nc) continue;
> +
> +        usbs = realloc(usbs, sizeof(libxl_device_usb)*((*num) + nc));
> +        for(j = 0; j < nc; j++) {

Coding style.

> +            usbs[*num].ctrl = tmp[j].ctrl;
> +            usbs[*num].port = tmp[j].port;
> +            usbs[*num].busid = strdup(tmp[j].busid);
> +            (*num)++;
> +        }
> +        free(tmp);
> +    }
> +    return usbs;
> +}
...
> +/* set default value */
> +static char *usb_busaddr_to_busid(libxl__gc *gc, int bus, int addr)
> +{
> +    libxl_ctx *ctx = libxl__gc_owner(gc);
> +    struct dirent *de;
> +    DIR *dir;
> +    char *busid = NULL;
> +
> +    if (bus < 1 || addr < 1)
> +        return NULL;
> +
> +    if (!(dir = opendir(SYSFS_USB_DEV)))
> +        return NULL;
> +
> +    while((de = readdir(dir))) {

Coding style.

> +        char *filename;
> +        void *buf;
> +        int busnum = -1;
> +        int devnum = -1;
> +
> +        if (!de->d_name)
> +            continue;
> +
> +        filename = GCSPRINTF(SYSFS_USB_DEV"/%s/devnum", de->d_name);
> +        if (!libxl_read_file_contents(ctx, filename, &buf, NULL))
> +            sscanf(buf, "%x", &devnum);
> +
> +        filename = GCSPRINTF(SYSFS_USB_DEV"/%s/busnum", de->d_name);
> +        if (!libxl_read_file_contents(ctx, filename, &buf, NULL))
> +            sscanf(buf, "%x", &busnum);
> +
> +        if (bus == busnum && addr == devnum) {
> +            busid = strdup(de->d_name);
> +            break;
> +        }
> +    }
> +
> +    closedir(dir);
> +    return busid;
> +}
> +
> +/* find first unused controller:port and give that to usb device */
> +static int
> +libxl__device_usb_set_default_usbctrl(libxl__gc *gc, uint32_t domid,
> +                                      libxl_device_usb *usb)
> +{
> +    libxl_ctx *ctx = CTX;
> +    libxl_device_usbctrl *usbctrls;
> +    libxl_device_usb *usbs = NULL;
> +    int numctrl, numusb, i, j, rc = -1;
> +    char *be_path, *tmp;
> +
> +    usbctrls = libxl_device_usbctrl_list(ctx, domid, &numctrl);
> +    if ( !numctrl)

Coding style.

> +        goto out;
> +
> +    for (i = 0; i < numctrl; i++) {
> +        rc = libxl__device_usb_list(gc, domid, usbctrls[i].devid,
> +                                    &usbs, &numusb);
> +        if (rc) continue;
> +
> +        if (!usbctrls[i].ports || numusb == usbctrls[i].ports)
> +            continue;
> +
> +        for (j = 1; i <= numusb; j++) {
> +            be_path = GCSPRINTF("%s/backend/vusb/%d/%d/port/%d",
> +                                libxl__xs_get_dompath(gc, 0), domid,
> +                                usbctrls[i].devid, j);
> +            tmp = libxl__xs_read(gc, XBT_NULL, be_path);
> +            if (tmp && !strcmp( tmp, "")) {
> +                usb->ctrl = usbctrls[i].devid;
> +                usb->port = j;
> +                break;
> +            }
> +        }
> +    }
> +
> +    rc = 0;
> +
> +out:
> +    if (usbctrls)
> +        free(usbctrls);
> +    if (usbs)
> +        free(usbs);
> +    return rc;
> +}
> +
> +static int libxl__device_usb_setdefault(libxl__gc *gc, uint32_t domid,
> +                                        libxl_device_usb *usb)
> +{
> +    char *be_path, *tmp;
> +
> +    if (usb->ctrl == -1) {
> +        int ret = libxl__device_usb_set_default_usbctrl(gc, domid, usb);
> +        /* If no existing ctrl to host this usb device, setup a new one */
> +        if (ret) {
> +            libxl_device_usbctrl usbctrl;
> +            libxl_device_usbctrl_init(&usbctrl);
> +            libxl__device_usbctrl_add(gc, domid, &usbctrl);
> +            usb->ctrl = usbctrl.devid;
> +            usb->port = 1;
> +            libxl_device_usbctrl_dispose(&usbctrl);
> +        }
> +    }
> +
> +    be_path = GCSPRINTF("%s/backend/vusb/%d/%d/port/%d",
> +                        libxl__xs_get_dompath(gc, 0),
> +                        domid, usb->ctrl, usb->port);
> +    tmp = libxl__xs_read(gc, XBT_NULL, be_path);
> +    if (!tmp || strcmp(tmp, "") ){

Coding style.

> +        LOG(ERROR, "The controller port isn't available");
> +        return ERROR_INVAL;
> +    }
> +
> +    return 0;
> +}
...
> +static int bind_usb_intf(libxl__gc *gc, char *intf, char *drvpath)
> +{
> +    char *path;
> +    struct stat st;
> +    int fd, rc = 0;
> +
> +    path = GCSPRINTF("%s/%s", drvpath, intf);
> +    rc = lstat(path, &st);
> +    /* already bind, return */
> +    if(rc == 0)

Coding style.

> +        return 0;
> +
> +    path = GCSPRINTF("%s/bind", drvpath);
> +    fd = open(path, O_WRONLY);
> +    if (fd < 0)
> +        return ERROR_FAIL;
> +
> +    rc = write(fd, intf, strlen(intf));
> +    close(fd);
> +    if (rc < 0)
> +        return ERROR_FAIL;
> +
> +    return 0;
> +}
> +
> +/* Is usb interface bound to usbback? */
> +static int usb_intf_is_assigned(libxl__gc *gc, char *intf)
> +{
> +    char *spath;
> +    int rc;
> +    struct stat st;
> +
> +    spath = GCSPRINTF(SYSFS_USBBACK_DRIVER"/%s", intf);
> +    rc = lstat(spath, &st);
> +
> +    if(rc == 0)

Coding style.

> +        return 1;
> +    if (rc < 0 && errno == ENOENT)
> +        return 0;
> +    LOGE(ERROR, "Accessing %s", spath);
> +    return -1;
> +}


Juergen