[PATCH v5 0/9] Add vduse live migration features

[Maxime Coquelin]

On Mon, Oct 19, 2026 at 3:48 PM Eugenio Pérez <eperezma at redhat.com> wrote:
>
> This series introduces features to the VDUSE (vDPA Device in Userspace) driver
> to support Live Migration.
>
> Currently, DPDK does not support VDUSE devices live migration because the
> driver lacks a mechanism to suspend the device and quiesce the rings to
> initiate the switchover.  This series implements the suspend operation to
> address this limitation.
>
> Furthermore, enabling Live Migration for devices with control virtqueue
> requires two additional features.  Both of them are included in this series.
>
> * Address Spaces ID (ASID) support: This allows QEMU to isolate and intercept
>   the device's CVQ. By doing so, QEMU is able to migrate the device status
>   transparently, without requiring the device to support state save and
>   restore.
> * QUEUE_READY: This allows QEMU to control when the dataplane virtqueues are
>   enabled.  This ensures the dataplane is started after the device
>   configuration has been fully restored via the CVQ.
>
> It also enables the VIRTIO_NET_F_STATUS feature.  This allows the device to
> signal the driver that it needs to send gratuitous ARP with
> VIRTIO_NET_S_ANNOUNCE, reducing the Live Migration downtime.
>
> v5:
> * Update headers to 7.3
> * Rebase on top of main, merge conflicts.
>
> v4:
> * Rebase on top of origin/main, which already includes the __counted_by error
> fix.
> * Add VDUSE_SUSPEND to lib/vhost/vduse.c:vduse_reqs_str (Maxime).
>
> v3:
> * Include uapi/linux/stddef.h and revert the -D__counted_by from v2.
>
> v2:
> * Add -D__counted_by(X)= if the compiler does not support it. It is
>   pulled by the kernel headers.
>
> PATCH v1:
> * Move to VDUSE_SET_FEATURES ioctl instead of config space field.
> * Add a few bounds control.
> * Update kernel headers to v7.3-rc3.
>
> RFC v4:
> * Sync headers with Linux's latest existing and proposed UAPI.  Both
>   files constants and new ioctl VDUSE_SET_FEATURES.
> * Check for more error conditions and clarified some error messages in
>   ready message processing.
> * Add relevant release notes.
> * Fix cosmetic whitespaces & checkpath errors.
> * Fix error path of vhost_user_iotlb_init and vhost_user_iotlb_init_one.
> * Fix commits author.
>
> RFC v3:
> * Replace incorrect '%lx' DEBUG print format specifier with PRIx64
>
> RFC v2:
> * Following latest comments on kernel series about VDUSE features, not checking
>   API version but only check if VDUSE_GET_FEATURES success.
> * Move the start and last declarations in the braces as gcc 8 does not like
>   them interleaved with statements. Actually, I think the move was a mistake in
>   the first version.
>   https://mails.dpdk.org/archives/test-report/2026-February/958175.html
>
> Eugenio Pérez (3):
>   uapi: import VDUSE and VFIO header from v7.3 kernel
>   vhost: Support VDUSE QUEUE_READY feature
>   vhost: Support vduse suspend feature
>
> Maxime Coquelin (6):
>   vhost: introduce ASID support
>   vhost: add VDUSE API version negotiation
>   vhost: add virtqueues groups support to VDUSE
>   vhost: add ASID support to VDUSE IOTLB operations
>   vhost: claim VDUSE support for API version 1
>   vhost: add net status feature to VDUSE
>
>  kernel/linux/uapi/linux/iommufd.h | 105 +++++++++++-
>  kernel/linux/uapi/linux/stddef.h  |   4 +
>  kernel/linux/uapi/linux/vduse.h   | 113 ++++++++++++-
>  kernel/linux/uapi/linux/vfio.h    |  51 +++++-
>  kernel/linux/uapi/version         |   2 +-
>  lib/vhost/iotlb.c                 | 233 +++++++++++++++++----------
>  lib/vhost/iotlb.h                 |  14 +-
>  lib/vhost/vduse.c                 | 259 +++++++++++++++++++++++++++---
>  lib/vhost/vduse.h                 |   3 +-
>  lib/vhost/vhost.c                 |  16 +-
>  lib/vhost/vhost.h                 |  16 +-
>  lib/vhost/vhost_user.c            |  13 +-
>  12 files changed, 676 insertions(+), 153 deletions(-)
>
> --
> 2.56.0
>

applied to next-virtio/for-next-net.

Thanks!
Maxime