Re: [PATCH v5 0/3] vhost: fix the IO error after live migration

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Apr 15, 2025 at 10:47:25PM -0400, Haoqian He wrote:
> At the end of the VM live migration, the vhost device will be stopped.
> Currently, if the vhost-user backend crashes, vhost device's set_status()
> would not return failure, live migration won't perceive the disconnection
> with the backend. After the live migration is successful, the stale inflight
> IO will be submitted to the migration target host, which may be leading to
> the IO error.
> 
> The following patch series fixes the issue by making the live migration
> aware of the loss of connection with the vhost-user backend and aborting
> the live migration.

tagged, thanks a lot!


yet something to improve:

in the future pls post a new thread, not part of old thread.

also in the future, pls do not quote a huge mail just to add two lines
at the end, snip.



> ---
>   v1 ... v2
>     1. Fix some grammar issues in commit message.
>     2. Remove assert in vhost_scsi_common_stop and return error upwards.
> 
>   v2 ... v3
>     1. Added more detailed comments and commit message.
>     2. Change the newly added type name and parameter name.
>     3. Remove set_status_ext, change the return type of set_status to int.
> 
>   v3 ... v4
>     1. Call set_status() only if the function pointer is not NULL in the
>        3rd patch.
>     2. Add the more detailed commit messages for the 3rd patch.
> 
>   v4 ... v5
>     1. Fix code style issues in patch v4.
>     2. Rebased on master.
> 
> Haoqian He (3):
>   system/runstate: add VM state change cb with return value
>   vhost: return failure if stop virtqueue failed in vhost_dev_stop
>   vhost-user: return failure if backend crash when live migration
> 
>  backends/vhost-user.c                  | 20 +++++++--------
>  hw/block/vhost-user-blk.c              | 27 +++++++++++---------
>  hw/block/virtio-blk.c                  |  7 +++---
>  hw/char/virtio-serial-bus.c            |  3 ++-
>  hw/core/vm-change-state-handler.c      | 18 ++++++++-----
>  hw/display/vhost-user-gpu.c            | 12 ++++++---
>  hw/input/virtio-input.c                |  3 ++-
>  hw/net/virtio-net.c                    |  3 ++-
>  hw/scsi/scsi-bus.c                     |  2 +-
>  hw/scsi/vhost-scsi-common.c            | 13 +++++-----
>  hw/scsi/vhost-scsi.c                   |  5 ++--
>  hw/scsi/vhost-user-scsi.c              | 18 +++++++------
>  hw/vfio/migration.c                    |  2 +-
>  hw/virtio/vdpa-dev.c                   |  5 ++--
>  hw/virtio/vhost-user-base.c            | 23 ++++++++++-------
>  hw/virtio/vhost-user-fs.c              | 23 ++++++++++-------
>  hw/virtio/vhost-user-scmi.c            | 27 ++++++++++++--------
>  hw/virtio/vhost-user-vsock.c           | 15 +++++++----
>  hw/virtio/vhost-vsock-common.c         | 12 ++++-----
>  hw/virtio/vhost-vsock.c                | 11 ++++----
>  hw/virtio/vhost.c                      | 23 +++++++++--------
>  hw/virtio/virtio-balloon.c             |  3 ++-
>  hw/virtio/virtio-crypto.c              |  3 ++-
>  hw/virtio/virtio-iommu.c               |  3 ++-
>  hw/virtio/virtio-rng.c                 |  5 ++--
>  hw/virtio/virtio.c                     | 22 ++++++++++------
>  include/hw/virtio/vhost-scsi-common.h  |  2 +-
>  include/hw/virtio/vhost-vsock-common.h |  2 +-
>  include/hw/virtio/vhost.h              |  8 +++---
>  include/hw/virtio/virtio.h             |  2 +-
>  include/system/runstate.h              | 13 +++++++---
>  include/system/vhost-user-backend.h    |  2 +-
>  system/cpus.c                          |  8 ++++--
>  system/runstate.c                      | 35 ++++++++++++++++++++++----
>  34 files changed, 239 insertions(+), 141 deletions(-)
> 
> -- 
> 2.44.0