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[OpenStack Infra <2103636@xxxxxxxxxxxxxxxxxx>]

Reviewed:  https://review.opendev.org/c/openstack/nova/+/944105
Committed: https://opendev.org/openstack/nova/commit/4e4262cd3dfc6e2c1b0859882d2bd4dceb8ed7d8
Submitter: "Zuul (22348)"
Branch:    master

commit 4e4262cd3dfc6e2c1b0859882d2bd4dceb8ed7d8
Author: René Ribaud <rribaud@xxxxxxxxxx>
Date:   Wed Mar 12 11:37:50 2025 +0100

    FUP Remove unnecessary PCI check
    
    This patch removes the _test_pci() method, which is no longer necessary
    since flavor-based requests can now be live migrated.
    
    The related tests have also been removed.
    
    This fixes a bug where a user requests a live migration with a
    flavor-based request and NUMA constraints (e.g., CPU affinity). In
    this case, the code encounters the _test_pci() method and fails because
    the check was originally designed to enforce port-based requests only,
    causing an unnecessary failure.
    
    Notes: This issue was discovered through functional tests that involve
    a mix of port-based and flavor-based requests. The failure in this
    scenario highlighted the unnecessary constraint.
    A functional test reproducing this issue in a mixed-mode scenario
    (port request + flavor-based request) will be provided in a subsequent
    FUP patch.
    
    The _test_pci() check was redundant, as a similar verification
    is already performed earlier in the migration process.
    
    Closes-Bug: 2103636
    Implements: blueprint migrate-vfio-devices-using-kernel-variant-drivers
    Change-Id: Icbeaadd94658ed44917d724446d484f6497f29e5


** Changed in: nova
       Status: In Progress => Fix Released

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https://bugs.launchpad.net/bugs/2103636

Title:
  Live Migration Fails for Flavor-Based Requests with NUMA Constraints
  Due to Redundant PCI Check

Status in OpenStack Compute (nova):
  Fix Released

Bug description:
  A bug occurs when a user requests a live migration with a flavor-based
  request that includes NUMA constraints (e.g., CPU affinity). The
  migration process hits the _test_pci() method, which incorrectly
  enforces a restriction allowing only port-based requests, causing the
  migration to fail unnecessarily.

  Expected Behavior:

  Live migration should succeed for flavor-based requests with NUMA
  constraints, as these are now supported.

  Actual Behavior:

  Live migration fails due to the _test_pci() method, which wrongly
  rejects flavor-based requests under the assumption that only port-
  based requests are valid.

  Steps to Reproduce:

      Create an instance with a flavor-based request that includes NUMA constraints (e.g., CPU affinity).
      Initiate a live migration.
      Observe that the migration fails at the _test_pci() method due to an unnecessary restriction.

  Root Cause:

      The _test_pci() check is redundant as a similar verification is already performed earlier in the migration process.
      The check incorrectly assumes that only port-based requests should pass, while flavor-based requests should also be allowed.

  Proposed Fix:

      Remove the _test_pci() method, as it is no longer necessary.
      Ensure that functional tests cover mixed-mode scenarios (port-based + flavor-based requests) to prevent regressions.

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