Re: [PATCH 1/2] qxl: remove assert in qxl_pre_save.

[Gerd Hoffmann <kraxel@redhat.com>]

On Thu, Jul 22, 2021 at 03:44:54PM +0100, Dr. David Alan Gilbert wrote:
> * Gerd Hoffmann (kraxel@redhat.com) wrote:
> > Since commit 551dbd0846d2 ("migration: check pre_save return in
> > vmstate_save_state") the pre_save hook can fail.  So lets finally
> > use that to drop the guest-triggerable assert in qxl_pre_save().
> > 
> > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> > ---
> >  hw/display/qxl.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/hw/display/qxl.c b/hw/display/qxl.c
> > index 84f99088e0a0..3867b94fe236 100644
> > --- a/hw/display/qxl.c
> > +++ b/hw/display/qxl.c
> > @@ -2283,7 +2283,9 @@ static int qxl_pre_save(void *opaque)
> >      } else {
> >          d->last_release_offset = (uint8_t *)d->last_release - ram_start;
> >      }
> > -    assert(d->last_release_offset < d->vga.vram_size);
> > +    if (d->last_release_offset < d->vga.vram_size) {
> > +        return 1;
> 
> It would be great if there was an error_report or something there
> so that we get some idea of what happened.

Hmm.  Strictly speaking qemu_log_mask(LOG_GUEST_ERROR, "..."); would be
the correct approach here, but I guess that wouldn't help much for
trouble-shooting as the message would only show up with "-d
guest_errors".  So better make that error_report("...") ?

take care,
  Gerd