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

[Paolo Bonzini <pbonzini@redhat.com>]

Il 19/07/2013 13:09, Alexey Kardashevskiy ha scritto:
> Hi!
> 
> This patch also breaks virtio on powerpc. I thought it was fixed
> (reverted?) in the master branch from qemu.org but it is still there. What
> did I miss?

It was not reverted, only the "DEVICE_LITTLE_ENDIAN" marking was.

Let me check if I can reproduce this, it looks like a endianness
problems reading virtio-blk config space.

Paolo

> Trying to load:  from: disk ... virtioblk_read: Access beyond end of device!
> virtioblk_read: Access beyond end of device!
> virtioblk_read: Access beyond end of device!
> virtioblk_read: Access beyond end of device!
> virtioblk_read: Access beyond end of device!
> virtioblk_read: Access beyond end of device!
> virtioblk_read: Access beyond end of device!
> virtioblk_read: Access beyond end of device!
> virtioblk_read: Access beyond end of device!
> virtioblk_read: Access beyond end of device!
> virtioblk_read: Access beyond end of device!
> virtioblk_read: Access beyond end of device!
> [many of those]
> 
> 
> 
> On 07/11/2013 10:29 PM, Alexander Graf wrote:
>>
>> On 24.06.2013, at 08:07, Jan Kiszka wrote:
>>
>>> On 2013-06-23 22:50, Hervé Poussineau wrote:
>>>> Jan Kiszka a écrit :
>>>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>>>
>>>>> 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 <jan.kiszka@siemens.com>
>>>>> ---
>>>>
>>>> ...
>>>>
>>>>> +
>>>>> +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.
>>>
>>> Anything behind PIO is little endian, of course. Will add this.
>>
>> This patch breaks VGA on PPC as it is in master today.
>>
>>
>> Alex
>>
>>>
>>>>
>>>> This fixes PPC PReP emulation, which would otherwise be broken with this
>>>> patchset.
>>>
>>> Thanks,
>>> Jan
>>>
>>>
>>
>>
> 
>