Quoting Peter Lieven (2016-09-13 10:52:04) > > > > Am 13.09.2016 um 17:42 schrieb Stefan Hajnoczi <stefa...@redhat.com>: > > > >> On Thu, Sep 08, 2016 at 03:58:26PM -0500, Michael Roth wrote: > >> Quoting Stefan Hajnoczi (2016-09-05 12:54:35) > >>>> On Fri, Aug 26, 2016 at 01:45:56PM +0200, Peter Lieven wrote: > >>>>> Am 25.08.2016 um 19:23 schrieb Michael Roth: > >>>>> Quoting Peter Lieven (2016-08-25 01:38:13) > >>>>>> 7c509d1 virtio: decrement vq->inuse in virtqueue_discard() > >>>>>> 700f26b virtio: recalculate vq->inuse after migration > >>>>> Looks like these got posted during the freeze :( > >>>>> > >>>>>> The virtio thing is important because live migration is broken without > >>>>>> the fix as 86cc089 is in 2.6.1. > >>>>> Not sure I understand the relation to 86cc089. Wouldn't the check > >>>>> introduced there always pass due to target initializing inuse to 0? > >>>>> > >>>>> Or is the issue that the fix introduced in 86cc089 is only partially > >>>>> effective due to inuse not being recalculated properly on target? That > >>>>> might > >>>>> warrant a 2.6.1.1... > >>>> > >>>> This is what Stefan wrote in the cover letter to the series: > >>>> > >>>> "I should mention this is for QEMU 2.7. These fixes are needed if the > >>>> CVE-2016-5403 patch has been applied. Without these patches any device > >>>> that holds VirtQueueElements acros > >>>> live migration will terminate with a "Virtqueue size exceeded" error > >>>> message. virtio-balloon and virtio-scsi are affected. virtio-bl > >>>> probably too but I haven't tested it." > >>>> > >>>> Maybe > >>> > >>> The virtio inuse fixes are needed for stable (v2.6.2?) so that the > >>> spurious "Virtqueue size exceeded" on migration is solved. > >>> > >>> The error can be reproduced when there is a VirtQueueElement pending > >>> across migration (e.g. virtio-blk s->rq failed request list). > >> > >> Thanks for clarifying. I'm planning to do a 2.6.2 to capture these, the > >> patches Peter mentioned, and some other fixes that came during 2.7 RC > >> phase. > >> > >> I have an initial staging tree at: > >> > >> https://github.com/mdroth/qemu/commits/stable-2.6-staging > >> > >> There's still a few PULLs in flight with patches I plan to pull in, but > >> hoping to send out the patch round-up early next week and a release the > >> following week. > > > > Two more candidates for stable: > > > > 4b7f91e virtio: zero vq->inuse in virtio_reset() > > 104e70c virtio-balloon: discard virtqueue element on reset > > > > They also deal with "Virtqueue size exceeded" errors. > > > > Stefan > > There also seems to be an regression (segfault) in the VNC server in 2.6.1, > but i am still investigating.
Do you have a reproducer? I can try a bisect. Trying to get the initial staging tree posted today but want to make sure any known regressions are addressed beforehand. > > Peter
