Re: [PATCH v7 11/12] virtio-serial-bus: add terminal resize messages

["Daniel P. Berrangé" <berrange@redhat.com>]

On Tue, Jun 09, 2026 at 09:16:21PM +0200, Filip Hejsek wrote:
> Implement the part of the virtio spec that allows to notify the virtio
> driver about terminal resizes. Gate the new resize support behind the
> console-size property, which defaults to off. To implement the property,
> restore VirtIOSerial::host_features (previously removed by commit
> d0660e5b7fc7e97926232d13d2500a16df32b310).
> 
> The virtio spec contains two methods to inform the guest about console
> size:
> 
> 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. Unfortunately, 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 running an
> old guest kernel, the number of rows and columns will be swapped.
> 
> Based on a patch originally written by Szymon Lukasz <noh4hss@gmail.com>,
> but partially rewritten to fix various corner cases.
> 
> Signed-off-by: Szymon Lukasz <noh4hss@gmail.com>
> Signed-off-by: Filip Hejsek <filip.hejsek@gmail.com>
> ---
>  hw/char/trace-events              |  1 +
>  hw/char/virtio-serial-bus.c       | 81 ++++++++++++++++++++++++++++++++++++++-
>  include/hw/virtio/virtio-serial.h |  7 ++++
>  3 files changed, 87 insertions(+), 2 deletions(-)

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>


With regards,
Daniel
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