On Tue, 2026-10-20 at 19:56 +0400, [email protected] 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 <[email protected]>, > > but partially rewritten to fix various corner cases. > > > > Signed-off-by: Szymon Lukasz <[email protected]> > > Signed-off-by: Filip Hejsek <[email protected]> > > Message-ID: <[email protected]> > > --- > > 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(-) > > > > diff --git a/hw/char/trace-events b/hw/char/trace-events > > index a3fcc772877a..e387c8853fcf 100644 > > --- a/hw/char/trace-events > > +++ b/hw/char/trace-events > > @@ -11,6 +11,7 @@ serial_update_parameters(uint64_t baudrate, char parity, > > int data_bits, int stop > > > > > > # virtio-serial-bus.c > > virtio_serial_send_control_event(unsigned int port, uint16_t event, > > uint16_t value) "port %u, event %u, value %u" > > +virtio_serial_send_console_resize(unsigned int port, uint16_t cols, > > uint16_t rows) "port %u, cols %u, rows %u" > > virtio_serial_throttle_port(unsigned int port, bool throttle) "port %u, > > throttle %d" > > virtio_serial_handle_control_message(uint16_t event, uint16_t value) > > "event %u, value %u" > > virtio_serial_handle_control_message_port(unsigned int port) "port %u" > > diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c > > index c36e18a4cfb5..882765ac88ab 100644 > > --- a/hw/char/virtio-serial-bus.c > > +++ b/hw/char/virtio-serial-bus.c > > @@ -261,6 +261,68 @@ static size_t send_control_event(VirtIOSerial *vser, > > uint32_t port_id, > > return send_control_msg(vser, &cpkt, sizeof(cpkt)); > > } > > > > > > +/* > > + * This struct should be added to the Linux kernel uapi headers > > + * and later imported to standard-headers/linux/virtio_console.h > > + */ > > +struct virtio_console_resize { > > + __virtio16 cols; > > + __virtio16 rows; > > +}; > > + > > +static void send_console_resize(VirtIOSerialPort *port) > > +{ > > + VirtIOSerial *vser = port->vser; > > + VirtIODevice *vdev = VIRTIO_DEVICE(vser); > > + > > + if (!virtio_has_feature(vser->host_features, VIRTIO_CONSOLE_F_SIZE)) { > > + return; > > + } > > + > > + trace_virtio_serial_send_console_resize(port->id, port->cols, > > port->rows); > > + > > + if (use_multiport(vser)) { > > it should probably gate on negotiated virtio_vdev_has_feature(vdev, > VIRTIO_CONSOLE_F_SIZE) as well
I think the patch is already merged [1]? I'm not familiar with all details of the QEMU development process. Should I address this in a follow-up commit? [1]: https://lore.kernel.org/qemu-devel/[email protected]/ -- Filip
