Il 08/09/2014 15:44, Benoît Canet ha scritto:
>> > + if (bs->bl.max_transfer_length && nb_sectors >
>> > bs->bl.max_transfer_length) {
>> > + error_report("read of %d sectors at sector %ld exceeds device max"
>> > + " transfer length of %d sectors.", nb_sectors,
>> > sector_num,
>> > + bs->bl.max_transfer_length);
>> > + return -EINVAL;
>> > + }
>> > +
>> > return bdrv_co_do_preadv(bs, sector_num << BDRV_SECTOR_BITS,
>> > nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
>> > }
>> > @@ -3507,6 +3514,13 @@ static int coroutine_fn
>> > bdrv_co_do_writev(BlockDriverState *bs,
>> > return -EINVAL;
>> > }
>> >
>> > + if (bs->bl.max_transfer_length && nb_sectors >
>> > bs->bl.max_transfer_length) {
>> > + error_report("write of %d sectors at sector %ld exceeds device
>> > max"
>> > + " transfer length of %d sectors.", nb_sectors,
>> > sector_num,
>> > + bs->bl.max_transfer_length);
>> > + return -EINVAL;
>> > + }
>> > +
>> > return bdrv_co_do_pwritev(bs, sector_num << BDRV_SECTOR_BITS,
>> > nb_sectors << BDRV_SECTOR_BITS, qiov,
>> > flags);
>> > }
>> > --
>> > 1.7.9.5
>> >
>> >
> Look like you are changing the coroutine version.
>
> Some hardware like virtio-blk uses the AIO version of read and writes.
> What would happen if all the block drivers down the chain are AIO enabled ?
The AIO version still goes through bdrv_co_do_readv/writev.
However, error_report is not something you can use for guest-accessible
error messages, unless you want your logs to fill up with error messages. :)
Paolo
