Re: [Qemu-devel] [PULL 6/6] Monitor: Make output buffer dynamic

[Anthony Liguori <aliguori@us.ibm.com>]

Luiz Capitulino <lcapitulino@redhat.com> writes:

> On Tue, 2 Apr 2013 10:37:01 -0400
> Luiz Capitulino <lcapitulino@redhat.com> wrote:
>
>> On Mon, 01 Apr 2013 10:35:34 -0500
>> Anthony Liguori <aliguori@us.ibm.com> wrote:
>> 
>> > Luiz Capitulino <lcapitulino@redhat.com> writes:
>> > 
>> > > Commit f628926bb423fa8a7e0b114511400ea9df38b76a changed monitor_flush()
>> > > to retry on qemu_chr_fe_write() errors. However, the Monitor's output
>> > > buffer can keep growing while the retry is not issued and this can
>> > > cause the buffer to overflow.
>> > >
>> > > To reproduce this issue, just start qemu and type on the Monitor:
>> > >
>> > > (qemu) ?
>> > >
>> > > This will cause the assertion to trig.
>> > >
>> > > To fix this problem this commit makes the Monitor buffer dynamic,
>> > > which means that it can grow as much as needed.
>> > >
>> > > Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
>> > 
>> > This breaks hotplug according to git bisect.  The test output is:
>> 
>> I'm trying to reproduce this w/o qemu-test as you suggested on irc, but
>> what I'm getting is:
>> 
>> # ./qemu-qmp -enable-kvm -qmp unix:./qmp-sock,server,nowait -monitor stdio
>> QEMU 1.4.50 monitor - type 'help' for more information
>> (qemu) device_add virtio-blk-pci,drive=hd0
>> Property 'virtio-blk-pci.drive' can't find value 'hd0'
>> **
>> ERROR:/home/lcapitulino/work/src/upstream/qmp-unstable/qom/object.c:1003:object_get_canonical_path: assertion failed: (obj->parent != NULL)
>> 
>> Also happens on master, so I'll bisect that one first...
>
> I was obviously missing a drive_add first, but the assertion is a bug
> anyway.

I've got a patch waiting to be pushed that fixes the assert.

Regards,

Anthony Liguori