Re: [PATCH RFC v5 08/12] virtio-serial-bus: add terminal resize messages

[Dominique Martinet <asmadeus@codewreck.org>]

Filip Hejsek wrote on Sun, Sep 21, 2025 at 01:45:38AM +0200:
> From: Szymon Lukasz <noh4hss@gmail.com>
> 
> Implement the part of the virtio spec that allows to notify the virtio
> driver about terminal resizes. The virtio spec contains two methods to
> achieve that:
> 
> For legacy drivers, we have only one port and we put the terminal size
> in the config space and inject the config changed interrupt.
> 
> For multiport devices, we use the control virtqueue to send a packet
> containing the terminal size. Note that old versions of the Linux kernel
> used an incorrect order for the fields (rows then cols instead of cols
> then rows), until it was fixed by commit 5326ab737a47278dbd16ed3ee7380b26c7056ddd.
> 
> As a result, when using a Linux kernel older than 6.15, the number of rows
> and columns will be swapped.

(subject to this part of the discussion being settled...)

> Signed-off-by: Szymon Lukasz <noh4hss@gmail.com>
> [Filip: swap rows/cols, console-size affects multiport too,
>         size config always updated, use use_multiport, move trace call]
> Signed-off-by: Filip Hejsek <filip.hejsek@gmail.com>

Reviewed-by: Dominique Martinet <dominique.martinet@codewreck.org>
Tested-by: Dominique Martinet <dominique.martinet@codewreck.org>

> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index 38c949c4f2ce4a117cbfca62f56919711ce392b4..74a747ec6578c958b35e1f9712e5dbed7bca72e8 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -37,7 +37,9 @@
>  #include "hw/virtio/virtio-iommu.h"
>  #include "audio/audio.h"
>  
> -GlobalProperty hw_compat_10_1[] = {};
> +GlobalProperty hw_compat_10_1[] = {
> +    { "virtio-serial-device", "console-size", "off" },

Oh the original patches had this wrong, good catch!

-- 
Dominique Martinet | Asmadeus