On Tue, 13 Aug 2019 08:45:49 +0200 Jens Freimann <jfreim...@redhat.com> wrote:
> On Mon, Aug 12, 2019 at 03:22:52PM -0600, Alex Williamson wrote: > >On Mon, 12 Aug 2019 17:18:54 +0200 > >Cornelia Huck <coh...@redhat.com> wrote: > > > >> On Fri, 2 Aug 2019 17:05:59 +0200 > >> Jens Freimann <jfreim...@redhat.com> wrote: > >> > >> > As usual block all vfio-pci devices from being migrated, but make an > >> > exception for failover primary devices. This is achieved by setting > >> > unmigratable to 0 but also add a migration blocker for all vfio-pci > >> > devices except failover primary devices. These will be unplugged before > >> > migration happens by the migration handler of the corresponding > >> > virtio-net standby device. > >> > > >> > Signed-off-by: Jens Freimann <jfreim...@redhat.com> > >> > --- > >> > hw/vfio/pci.c | 24 +++++++++++++++++++++++- > >> > hw/vfio/pci.h | 1 + > >> > 2 files changed, 24 insertions(+), 1 deletion(-) > >> This patch interacts with support for vfio migration (last posted in > >> <1562665760-26158-1-git-send-email-kwankh...@nvidia.com>, I've not seen > >> a later version yet.) > >> > >> With that, we'd have three cases to consider: > >> 1) device is a failover primary > >> 2) device has a migration region > >> 3) none of the above > >> > >> Can 1) and 2) happen simultaneously? If yes, what should take > >> precedence? > > > >Great questions. I would assume that a user specifying this option > >intends the behavior here regardless of the device's support for > >migration, which could be made more clear and easier to test by adding > >this option to other, otherwise migratable, QEMU NICs. > > I agree and think it makes sense that if a user intentionally marks a > device as a primary device of a failover pair then it should override > the use of an existing migration region of the device. Yes, that makes sense to me as well.
