Re: [Qemu-devel] [PATCH v1 1/2] virtio_gpu: Handle endian conversion

[Farhan Ali <alifm@linux.vnet.ibm.com>]

On 09/13/2017 04:13 AM, Gerd Hoffmann wrote:
> Please move this to a helper function, maybe by updating the
> VIRTIO_GPU_FILL_CMD macro.
>
> The header fields should be byteswapped too.  As most structs have
> 32bit fields only (with the exception of hdr.fence_id) you should be
> able to create a generic byteswap function which only needs the struct
> size as argument and handles all structs without addresses/offsets
> (which are 64bit fields).

I am not sure if I understand what you mean here. Since struct 
virtio_gpu_ctrl_hdr is part of every struct, so any such function
would also need to handle the case of hdr.fence_id, right?

>
> The conversion looks incomplete, at least virtio_gpu_ctrl_response will
> need adaptions too.  It probably works by luck because the guest driver
> uses fences only in virgl (3d) mode.
>

Oh right, I need to handle the conversion there as well. Thanks for 
catching that.

Also I believe this conversion patch isn't comprehensive, it's mostly 
the changes I made to get a display working on S390. So I appreciate
you reviewing the changes.

> cheers,
>   Gerd

Thanks
Farhan