[PATCH QEMU HCI-8.0 v6 00/12] usb-host: support CPR migration

[Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>]

v5 -> v6:

Substantial changes:

  * Drain each usb-host from a vm-state change handler when the VM stops
    for CPR (RUN_STATE_FINISH_MIGRATE), before the device and interrupt
    controller are snapshotted.  A completion raised during the drain now
    lands in the still-live interrupt controller and is migrated, instead
    of being lost as it was when the drain ran from .pre_save() after the
    snapshot.

  * Deliver a cancelled transfer that moved some data as a short transfer
    instead of dropping it; a zero-progress one is suppressed for the
    target to replay from the start of the TD.  A VM already paused when
    migration starts keeps a suppress-all drain in .pre_save() as a
    fallback.

Minor changes (refactoring/cleanup):

  * Group the per-device CPR fields into one struct block; factor the
    drain-and-handoff tail into usb_host_cpr_quiesce(); fold the
    altsetting range check into the interface reclaim (one config
    descriptor read); register the exit notifier and vm-state handler
    only after the blocker, shrinking the realize error path.

  * Commit message and comment rewording, forward-declaration placement,
    and a checkpatch line-length fix.  No functional change.

v5: http://lore.virtuozzo.com/qemu/20260925-usb-host_v3-v5-0-e5b21724db4d@virtuozzo.com/

Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>
---
Andrey Drobyshev (12):
      usb-host: don't leak hostdev FD on open failure #VSTOR-137800
      usb-host: add migration blocker for CPR modes #VSTOR-137800
      usb-host: preserve hostdev FD during CPR migration #VSTOR-137800
      usb-host: factor out usb_host_reap_xfers() #VSTOR-137800
      usb-host: drain in-flight URBs across CPR #VSTOR-137800
      usb-host: re-issue drained URBs if CPR is aborted #VSTOR-137800
      usb-host: skip product-string read on CPR incoming #VSTOR-137800
      usb-host: hand off the device across cpr-transfer #VSTOR-137800
      usb: migrate the interface altsetting #VSTOR-137800
      usb-host: reconfigure endpoints on CPR incoming #VSTOR-137800
      hcd-xhci: resync isochronous endpoints after CPR #VSTOR-137800
      usb-host: make CPR migration blocker conditional #VSTOR-137800

 hw/usb/bus.c         |  36 ++++
 hw/usb/hcd-xhci.c    |  20 ++
 hw/usb/host-libusb.c | 525 +++++++++++++++++++++++++++++++++++++++++++++++----
 3 files changed, 542 insertions(+), 39 deletions(-)
---
base-commit: f3c1d9ef263edfab8d2a273078493bb766dcf8f8
change-id: 20260914-usb-host_v3-bbfea86d1dad

Best regards,
--  
Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>