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[OpenStack Infra <2098496@xxxxxxxxxxxxxxxxxx>]

Reviewed:  https://review.opendev.org/c/openstack/nova/+/944277
Committed: https://opendev.org/openstack/nova/commit/229fb3513ae39fa120167107afe42568ca85ace9
Submitter: "Zuul (22348)"
Branch:    master

commit 229fb3513ae39fa120167107afe42568ca85ace9
Author: Balazs Gibizer <gibi@xxxxxxxxxx>
Date:   Thu Mar 13 16:24:27 2025 +0100

    Ignore metadata tags in pci/stats _find_pool logic
    
    The stats module uses the _find_pool() call to find a matching pool for
    a new device or a device that is being deallocated. If no existing pool
    matches with the dev then then a new pool is created for it. The
    pool matching logic was faulty as it did not remove all the metadata
    keys from the pool like rp_uuid. So if the dev did not have that key but
    the pool did then the dev did not match.
    
    On the other hand the PCI allocation logic (when PCI in Placement is
    enabled) assumed that devices from a single rp_uuid are always in a
    single pool. As this assumption was broken by the above bug the PCI
    allocation blindly tried to allocate resources for an rp_uuid from each
    matching pool causing overallocation.
    
    The main fix in this patch is to ignore the metadata tags in
    _find_pool(). But also two safety net are added to the allocation logic.
    The logic now asserts that the assumption is correct and if not (i.e. it
    found multiple pools with the same rp_uuid) then it bails out. It also
    does not ever blindly allocate the same rp_uuid request from multiple
    pools.
    
    Closes-Bug: #2098496
    Change-Id: I9678230397fa1a3c735ee01ed756d5af3b4e1191


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

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https://bugs.launchpad.net/bugs/2098496

Title:
  VM gets more PCI hostdevs than requested when PCI in Placement is
  enabled with VFs

Status in OpenStack Compute (nova):
  Fix Released

Bug description:
  Reproduce:
  * create devstack from recent master with device_spec config enabling multiple VFs per PF
  * enable pci in placement feature
  * create VM with a flavor requesting a single VF
  * observe the the VM got a single hostdev
  * delete the VM
  * observer that the device the VM was using is freed
  * create another VM with the same flavor requesting a single VF

  Expected:
  The VM gets a single hostdev

  Actual:
  The VM gets two hostdevs and it has two devices allocated both in the nova DB and in placement

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