Re: [Qemu-devel] [PATCH] ide: remove hardcoded 2GiB transactional limit

[John Snow <jsnow@redhat.com>]

On 10/27/2015 12:50 PM, Stefan Hajnoczi wrote:
> On Mon, Oct 26, 2015 at 07:38:02PM -0400, John Snow wrote:
>> Not that you can request a >2GiB transaction, but that's why checking
>> for it makes no sense anymore.
>>
>> With the newer 'limit' parameter to prepare_buf, we no longer need a
>> static limit. The maximum limit is still 2GiB, but the limit parameter
>> is set to the current transaction size, which cannot surpass 32MiB
>> (512 * 65536). If the PRDT surpasses the transactional size, then,
>> we'll just carry out the normative underflow handling pathways instead
>> of needing an extra, strange pathway that worries about hitting some
>> logistical cap for the largest sglist we can support -- we'll never
>> even attempt to build one that big anymore.
>>
>> Reported-by: Kevin Wolf <kwolf@redhat.com>
>> Signed-off-by: John Snow <jsnow@redhat.com>
>> ---
>>  hw/ide/ahci.c     | 30 ++++++++++++++----------------
>>  hw/ide/internal.h |  2 +-
>>  hw/ide/pci.c      |  7 -------
>>  3 files changed, 15 insertions(+), 24 deletions(-)
> 
> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
> 

Thanks, applied to my IDE tree:

https://github.com/jnsnow/qemu/commits/ide
https://github.com/jnsnow/qemu.git

--js