Hi Paolo,

On 12/14/2017 06:34 AM, Paolo Bonzini wrote:
> On 14/12/2017 10:06, Kevin Wolf wrote:
[...]
>> Doing this kind of thing over QMP doesn't look right to me. qtests
>> should access hardware the same way as real guests access the hardware
>> (i.e. MMIO and I/O ports).
[...]
> 
> Yeah, what we usually do is not test the device (e.g. SCSI) directly,
> but only through the HBA (e.g. virtio-scsi or AHCI, it would be SDHCI in
> this case).

Yes, a SDHCI qtest is added in a later series (in C) using MMIO access:
http://lists.nongnu.org/archive/html/qemu-devel/2017-12/msg02391.html

But to be sure the SDHCI is correct I needed a SD slave to behave
correctly ;) Hence this "bus test".

Regards,

Phil.