[Qemu-devel] [PATCH v4 0/5] virtio: fix some issues of "started" and "start_on_kick" flag

[elohimes@gmail.com]

From: Xie Yongji <xieyongji@baidu.com>

We introduced two flags "started" and "start_on_kick" to indicate virtio
device's state before. But there still are some problems with them. So
we try to fixup them in this patchset.

The patch 1 introduces a "use-started" property to avoid a migration
issue under Greg Kurz's suggestion [1].

The patch 2 set "start_on_kick" flag for legacy devices.

The patch 3 fixes a regression bug that old guest is not able to boot with
vhost-user-blk device.

The patch 4,5 fix some problems with "started" and "start_on_kick" flag.

[1] https://lists.gnu.org/archive/html/qemu-devel/2019-05/msg06247.html

v4:
- Patch 1 is rebased on commit 8e8cbed09ad9d5 ("hw: Nuke hw_compat_4_0_1 and
  pc_compat_4_0_1")

v3:
- change the order of patches
- Also disable "use-started" property by hw_compat_4_0

v2:
- Recalculate "start_on_kick" flag after migration instead of migrating
  it
- Set "start_on_kick" flag for legacy devices
- Avoid setting "started" flag when "use_started" property is true
- Set "use_started" to false by hw_compat_4_0_1 instead of hw_compat_4_0

Xie Yongji (5):
  virtio: add "use-started" property
  virtio: Set "start_on_kick" for legacy devices
  virtio: Set "start_on_kick" on virtio_set_features()
  virtio: Make sure we get correct state of device on
    handle_aio_output()
  virtio: Don't change "started" flag on virtio_vmstate_change()

 hw/block/vhost-user-blk.c  |  4 +--
 hw/core/machine.c          |  1 +
 hw/virtio/virtio.c         | 53 ++++++++++++++++++++++----------------
 include/hw/virtio/virtio.h | 23 ++++++++++++++++-
 4 files changed, 56 insertions(+), 25 deletions(-)

-- 
2.17.1