On Fri 27 Apr 2018 05:43:33 PM CEST, Eric Blake wrote:
>>> -static int bdrv_rw_co(BdrvChild *child, int64_t sector_num, uint8_t *buf,
>>> - int nb_sectors, bool is_write, BdrvRequestFlags
>>> flags)
>>> -{
>>> - QEMUIOVector qiov;
>>> - struct iovec iov = {
>>> - .iov_base = (void *)buf,
>>> - .iov_len = nb_sectors * BDRV_SECTOR_SIZE,
>>> - };
>>> -
>>> - if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
>>> - return -EINVAL;
>>> - }
>>
>> Do we have a check for BDRV_REQUEST_MAX_BYTES in the byte-based API?
>
> No, but we don't need one. First, note that bs->bl.max_transfer is
> currently uint32_t, so right now, no driver can set it any larger than
> 4G
But note that the old limit was based on a signed integer.
BDRV_REQUEST_MAX_SECTORS is 2147483136 bytes (a bit less than 2GB).
For 32-bit integers, (INT_MAX - 1) & ~511 = 2147483136
Berto
