Re: [Qemu-devel] [PATCH v3 11/14] ioport: Switch dispatching to memory core layer

[Anthony Liguori]

Hervé Poussineau <address@hidden> writes:

> Jan Kiszka a écrit :
>> From: Jan Kiszka <address@hidden>
>> 
>> The current ioport dispatcher is a complex beast, mostly due to the
>> need to deal with old portio interface users. But we can overcome it
>> without converting all portio users by embedding the required base
>> address of a MemoryRegionPortio access into that data structure. That
>> removes the need to have the additional MemoryRegionIORange structure
>> in the loop on every access.
>> 
>> To handle old portio memory ops, we simply install dispatching handlers
>> for portio memory regions when registering them with the memory core.
>> This removes the need for the old_portio field.
>> 
>> We can drop the additional aliasing of ioport regions and also the
>> special address space listener. cpu_in and cpu_out now simply call
>> address_space_read/write. And we can concentrate portio handling in a
>> single source file.
>> 
>> Signed-off-by: Jan Kiszka <address@hidden>
>> ---
>
> ...
>
>> +
>> +static void portio_write(void *opaque, hwaddr addr, uint64_t data,
>> +                         unsigned size)
>> +{
>> +    MemoryRegionPortioList *mrpio = opaque;
>> +    const MemoryRegionPortio *mrp = find_portio(mrpio, addr, size, true);
>> +
>> +    if (mrp) {
>> +        mrp->write(mrpio->portio_opaque, mrp->base + addr, data);
>> +    } else if (size == 2) {
>> +        mrp = find_portio(mrpio, addr, 1, true);
>> +        assert(mrp);
>> +        mrp->write(mrpio->portio_opaque, mrp->base + addr, data & 0xff);
>> +        mrp->write(mrpio->portio_opaque, mrp->base + addr + 1, data >> 8);
>> +    }
>> +}
>> +
>> +static const MemoryRegionOps portio_ops = {
>> +    .read = portio_read,
>> +    .write = portio_write,
>> +    .valid.unaligned = true,
>> +    .impl.unaligned = true,
>> +};
>> +
>
> You need to mark these operations as DEVICE_LITTLE_ENDIAN.
> In portio_write above, you clearly assume that data is in LE format.
>
> This fixes PPC PReP emulation, which would otherwise be broken with this 
> patchset.

Did you actually test that as this is how the code behaved previously?

Regards,

Anthony Liguori

>
> Hervé