[Qemu-devel] [PATCH v3 00/14] virtio migration: Flip outer layer to vmstate

["Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Hi,
  This series converts the outer most layer of virtio to
use VMState macros;  this is the easy bit, but I'm hoping that
having done that, the next trick is to nibble away at the virtio_save/load
functions and all of the zillions of device/bus helpers.

I think the first two patches are the most controversial;
they remove migration support for old version of virtio-net and virtio-serial;
(for virtio-net versions prior to 0.11 and for virtio-serial prior to 0.13).
I'm working on the basis that migration has bit rotted enough so
that the streams aren't migration compatible for that long back
on upstream - but if anyone knows otherwise please shout.

The reason for doing those is that the virtio structure makes
it a bit tricky to pass the outer device version number down
through VMState to the device specific code (I can do it
as a hack if necessary using a dummy is_needed function);
and with -net and -serial compatibility sorted I think
every other device just supports a single version.

My main reason for doing this is to get rid of the
calls to register_savevm ('going to disappear as soon..' since 2010)

It's lightly tested using the magic line:
./x86_64-softmmu/qemu-system-x86_64 -nographic -machine pc-i440fx-2.6,accel=kvm -cpu qemu64 -m 2048M -drive file=/home/vmimages/f20.img,if=none,id=drivea -device virtio-scsi,id=scsi -device scsi-hd,drive=drivea -device virtio-rng -device virtio-serial -chardev file,id=test,path=/tmp/testfile -device virtconsole,chardev=test,name=foo -virtfs local,path=/home,security_model=passthrough,mount_tag=host_share  -device virtio-gpu  -drive file=/home/vmimages/jeos-19-64.qcow2,id=jeos,if=none -device virtio-blk,drive=jeos  -device virtio-balloon

Thoughts?

Dave

v3
  Change virtio-gpu to use migrate_add_blocker instead of dummy vmstate,
    avoiding the problem of ending up with two vmstates for the one device.

Dr. David Alan Gilbert (14):
  virtio-net: Remove old migration version support
  virtio-serial: Remove old migration version support
  virtio: Migration helper function and macro
  virtio-scsi: Wrap in vmstate
  virtio-blk: Wrap in vmstate
  virtio-rng: Wrap in vmstate
  virtio-balloon: Wrap in vmstate
  virtio-net: Wrap in vmstate
  virtio-serial: Wrap in vmstate
  9pfs: Wrap in vmstate
  virtio-input: Wrap in vmstate
  virtio-gpu: Use migrate_add_blocker for virgl migration blocking
  virtio-gpu: Wrap in vmstate
  virtio: Update migration docs

 docs/virtio-migration.txt      |   6 ++-
 hw/9pfs/virtio-9p-device.c     |  14 ++----
 hw/block/virtio-blk.c          |  16 +++----
 hw/char/virtio-serial-bus.c    |  62 ++++++++-----------------
 hw/display/virtio-gpu.c        |  36 ++++++++-------
 hw/input/virtio-input.c        |  26 +++--------
 hw/net/virtio-net.c            | 102 ++++++++++++++++-------------------------
 hw/scsi/virtio-scsi.c          |  21 +++------
 hw/virtio/virtio-balloon.c     |  19 ++------
 hw/virtio/virtio-rng.c         |  20 ++------
 hw/virtio/virtio.c             |   6 +++
 include/hw/virtio/virtio-gpu.h |   2 +
 include/hw/virtio/virtio.h     |  20 ++++++++
 13 files changed, 145 insertions(+), 205 deletions(-)

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2.7.4