On 14/11/2018 18:17, Wei Liu wrote:
> Read from XEN_CONFIG_DIR/dom0-uuid. If it contains a valid UUID, set
> it for Dom0.
>
> Signed-off-by: Wei Liu <wei.l...@citrix.com>
[snip]
In general this looks good, however I am not familiar with libxl
conventions, so just some generic comments below.
> +static void get_dom0_uuid(libxl_uuid *uuid)
> +{
> + int fd = -1;
> + ssize_t r;
> + char uuid_buf[LIBXL_UUID_FMTLEN+1];
> +
> + libxl_uuid_clear(uuid);
> +
> + fd = open(DOM0_UUID_PATH, O_RDONLY);
> + if (fd < 0) {
> + fprintf(stderr, "failed to open %s\n", DOM0_UUID_PATH);
> + goto out;
> + }
> +
> + r = read(fd, uuid_buf, LIBXL_UUID_FMTLEN);
Could this be a short read? I'm not familiar with libxl conventions, but
would there be a utility function that repeats the read if it is short,
or would fread be better?
> + if (r == -1) {
> + fprintf(stderr, "failed to read %s, errno %d\n", DOM0_UUID_PATH,
> errno);
> + goto out;
> + }
> +
> + if (r != LIBXL_UUID_FMTLEN) {
> + fprintf(stderr, "file too short\n");
Would be nice to print which file is too short.
> + goto out;
> + }
> +
> + uuid_buf[LIBXL_UUID_FMTLEN] = 0;
> +
> + if (libxl_uuid_from_string(uuid, uuid_buf)) {
> + fprintf(stderr, "failed to parse UUID\n");
As above, would be nice to print which file this error is from.
> + libxl_uuid_clear(uuid);
> + }
> +
> +out:
> + if (fd >= 0) close(fd);
> +}
> +
> int main(int argc, char **argv)
> {
> int rc;
> - struct xs_handle *xsh;
> + struct xs_handle *xsh = NULL;
> + xc_interface *xch = NULL;
> char *domname_string = NULL, *domid_string = NULL;
> + libxl_uuid uuid;
>
> xsh = xs_open(0);
> if (!xsh) {
> fprintf(stderr, "cannot open xenstore connection\n");
> - exit(1);
> + rc = 1;
> + goto out;
> + }
> +
> + xch = xc_interface_open(NULL, NULL, 0);
> + if (!xch) {
> + fprintf(stderr, "xc_interface_open() failed\n");
> + rc = 1;
> }
>
> /* Sanity check: this program can only be run once. */
> @@ -31,7 +82,16 @@ int main(int argc, char **argv)
> goto out;
> }
>
> - rc = gen_stub_json_config(0, NULL);
> + get_dom0_uuid(&uuid);
> +
> + if (!libxl_uuid_is_nil(&uuid) &&
> + xc_domain_sethandle(xch, 0, libxl_uuid_bytearray(&uuid))) {
> + fprintf(stderr, "failed to set Dom0 UUID\n");
Can xc_domain_sethandle tell us why it failed?
> + rc = 1;
> + goto out;
> + }
> +
> + rc = gen_stub_json_config(0, &uuid);
> if (rc)
> goto out;
>
> @@ -55,6 +115,7 @@ out:
> free(domid_string);
> free(domname_string);
> xs_close(xsh);
> + xc_interface_close(xch);
I assume this function doesn't mind getting called with NULL, right?
Best regards,
--Edwin
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