On September 18, 2025 10:45:13 AM GMT+02:00, Maximilian Immanuel Brandtner <maxbr@linux.ibm.com> wrote:
> On Fri, 2025-09-12 at 05:39 +0200, Filip Hejsek wrote:
> > From: Szymon Lukasz <noh4hss@gmail.com>
> >
> > This function should be called whenever we learn about a new size of
> > the terminal connected to a chardev.
> >
> > Signed-off-by: Szymon Lukasz <noh4hss@gmail.com>
> > Signed-off-by: Filip Hejsek <filip.hejsek@gmail.com>
> > ---
> > chardev/char.c | 11 +++++++++++
> > include/chardev/char.h | 2 ++
> > 2 files changed, 13 insertions(+)
> >
> > diff --git a/chardev/char.c b/chardev/char.c
> > index
> > 635d19fea4fd4bd0c7f171f055fe940f9f5ebed5..b45d79cb9b57643827eb7479257
> > fdda2cf6b0434 100644
> > --- a/chardev/char.c
> > +++ b/chardev/char.c
> > @@ -351,6 +351,17 @@ int qemu_chr_wait_connected(Chardev *chr, Error
> > **errp)
> > return 0;
> > }
> >
> > +void qemu_chr_resize(Chardev *chr, uint16_t cols, uint16_t rows)
> > +{
> > + if (cols != chr->cols || rows != chr->rows) {
>
> Perhaps it would be better to discard resize events if the requested
> cols or rows is 0 as it indicates that an error has occurred at some
> point during the process of receiving the winsize.
Maybe. But then if the size actually changes from known
to unknown, it wouldn't be possible to get it back to the unknown
state. And what if only
one of the values is 0, and the other differs from the last value?
What I want to say is, I don't think QEMU should be in the business
of trying to fix broken size info. The kernel gave us zero,
so we should forward that and let the guest handle it.
> > + chr->cols = cols;
> > + chr->rows = rows;
> > + if (chr->be_open) {
> > + qemu_chr_be_event(chr, CHR_EVENT_RESIZE);
> > + }
> > + }
> > +}
> > +
> > QemuOpts *qemu_chr_parse_compat(const char *label, const char
> > *filename,
> > bool permit_mux_mon)
> > {
> > diff --git a/include/chardev/char.h b/include/chardev/char.h
> > index
> > 45cb6349756ac8072dffab9354108caf90cd3565..1e69b038241074d627ebb7f096e
> > 98aee9953ebdf 100644
> > --- a/include/chardev/char.h
> > +++ b/include/chardev/char.h
> > @@ -232,6 +232,8 @@ int qemu_chr_write(Chardev *s, const uint8_t
> > *buf, int len, bool write_all);
> > #define qemu_chr_write_all(s, buf, len) qemu_chr_write(s, buf, len,
> > true)
> > int qemu_chr_wait_connected(Chardev *chr, Error **errp);
> >
> > +void qemu_chr_resize(Chardev *chr, uint16_t cols, uint16_t rows);
> > +
> > #define TYPE_CHARDEV "chardev"
> > OBJECT_DECLARE_TYPE(Chardev, ChardevClass, CHARDEV)
> >
> >
>