Re: [PATCH v2 00/27] Virtio net failover fixes

[Michael S. Tsirkin]

On Wed, Dec 02, 2020 at 11:16:04AM +0100, Juan Quintela wrote:
> "Michael S. Tsirkin" <mst@redhat.com> wrote:
> > On Wed, Nov 18, 2020 at 09:37:21AM +0100, Juan Quintela wrote:
> >> Hi
> >> 
> >> This is a big rework of the network failover setup.  General idea is:
> >> * We don't cache the name of the primary/standby devices
> >>   We have several problems there with stale pointers
> >> * After this:
> >> - We can always remove either the primary/standby devices without trouble
> >> - Pluggin/unplugging works
> >> - We go to device opts to see what the failover device are.
> >>   Notice that we are plugging/unplugging the device, so it is not critical.
> >> - Once there, I "fixed" managedsave for libvirt (now gives an error 
> >> instead o=
> >> f just hanging)
> >> * Fields not cached anymore:
> >> - primary_device_dict
> >> - primary_device_opts
> >> - standby_id
> >> - primary_device_id
> >> - primary_dev
> >> * I renamed the should_be_hidden() callback to hide device, but if
> >>   people preffer the old name I can leave it.
> >> * Add (some) doc to some functions
> >> * Remove almost 100 lines of code while fixing things.
> >> 
> >> Please review.
> >
> > OK that's great, any of this appropriate for 5.2?
> > The memory leak fix maybe?
> 
> 1st one is also a fix, current code just hangs the guest.


Hmm it does but then proceeds when you unpause so I'm not sure
it's a good idea for 5.2. It's late in the cycle to try to
handle management bugs ...

> Rest of things .... current code fails a lot, but we are too late on the
> cycle.
> 
> Later, Juan.
> 
> 
> >> Later, Juan.
> >> 
> >> Juan Quintela (27):
> >>   migration: Network Failover can't work with a paused guest
> >>   failover: fix indentantion
> >>   failover: Use always atomics for primary_should_be_hidden
> >>   failover: primary bus is only used once, and where it is set
> >>   failover: Remove unused parameter
> >>   failover: Remove external partially_hotplugged property
> >>   failover: qdev_device_add() returns err or dev set
> >>   failover: Rename bool to failover_primary_hidden
> >>   failover: g_strcmp0() knows how to handle NULL
> >>   failover: Remove primary_device_opts
> >>   failover: remove standby_id variable
> >>   failover: Remove primary_device_dict
> >>   failover: Remove memory leak
> >>   failover: simplify virtio_net_find_primary()
> >>   failover: should_be_hidden() should take a bool
> >>   failover: Rename function to hide_device()
> >>   failover: virtio_net_connect_failover_devices() does nothing
> >>   failover: Rename to failover_find_primary_device()
> >>   failover: simplify qdev_device_add() failover case
> >>   failover: simplify qdev_device_add()
> >>   failover: make sure that id always exist
> >>   failover: remove failover_find_primary_device() error parameter
> >>   failover: split failover_find_primary_device_id()
> >>   failover: We don't need to cache primary_device_id anymore
> >>   failover: Caller of this two functions already have primary_dev
> >>   failover: simplify failover_unplug_primary
> >>   failover: Remove primary_dev member
> >> 
> >>  include/hw/qdev-core.h         |  28 ++--
> >>  include/hw/virtio/virtio-net.h |   9 +-
> >>  hw/core/qdev.c                 |  19 +--
> >>  hw/net/virtio-net.c            | 298 +++++++++++++--------------------
> >>  migration/migration.c          |  13 ++
> >>  softmmu/qdev-monitor.c         |  43 ++---
> >>  6 files changed, 167 insertions(+), 243 deletions(-)
> >> 
> >> --=20
> >> 2.26.2
> >>