Re: [PATCH v4 00/10] virtio-console: notify about the terminal size

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Sep 16, 2025 at 01:02:02AM +0200, Filip Hejsek wrote:
> While thinking about the patches, a few questions about the virtio spec
> have popped into my head.
> 
> 1. Should the config space size also be updated (for port 0) when
> multiport is used? Based on my reading of the spec, I think yes.
> 
> 2. Can VIRTIO_CONSOLE_RESIZE be sent if VIRTIO_CONSOLE_F_SIZE is not
> negotiated? The spec does not say, which I think means it can.

But the guest can't do anything useful here.

> 3. The spec says that reading from config space fields that are
> conditional on features should be allowed even if the driver has not
> (yet) accepted the feature. Does it mean that we have to update the
> size even if the feature is not accepted (yet), or is it OK if the
> reads return 0?

This is talking about the window before FEATURES_OK (and so DRIVER_OK)
is set.  It is best to update the size. There's no interrupt to send
though.


> Thanks for any answers or opinions,
> Filip Hejsek