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

[Philippe Mathieu-Daudé]

On 7/23/21 8:32 AM, Gerd Hoffmann wrote:
> 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("...") ?

It depends who is interested in such errors. Does management app care?