Re: [qemu-s390x] [PATCH 2/3] hw/s390x/css: Remove QEMU_PACKED from struct SenseId

[Thomas Huth]

On 2018-09-25 18:14, Cornelia Huck wrote:
> On Tue, 25 Sep 2018 17:20:08 +0200
> Thomas Huth <address@hidden> wrote:
> 
>> The uint16_t member cu_type of struct SenseId is not naturally aligned,
>> and since the struct is marked with QEMU_PACKED, this can lead to
>> unaligned memory accesses - which does not work on architectures like
>> Sparc. Thus remove the QEMU_PACKED here and rather copy the struct
>> byte by byte when we do copy_sense_id_to_guest().
> 
> Hm... would it look nicer if we chopped up {cu,dev}_type into a hi/lo
> byte and keep the QEMU_PACKED? (The ciws should be ok, I think.)

That will cause some ugly extra logic for the

  VMSTATE_UINT16(cu_type, SenseId)

in css.c instead. I'd like to avoid that, but if you insist, I can have
a try...

 Thomas