[PATCH v7 05/12] PCI: liveupdate: Keep bus numbers constant during Live Update

[Pasha Tatashin]

On Fri, 10 Jul 2026 21:26:08 +0000, David Matlack <dmatlack at google.com> wrote:
> During a Live Update, preserved devices must be allowed to continue
> performing memory transactions so the kernel cannot change the fabric
> topology, including bus numbers, since that would require disabling
> and flushing any memory transactions first.
> 
> To keep bus numbers constant, always inherit the secondary and
> subordinate bus numbers assigned to bridges during scanning, instead of
> assigning new ones, if any PCI devices are being preserved. Note that
> the kernel inherits bus numbers even on bridges without any downstream
> endpoints that were preserved. This avoids accidentally assigning a
> bridge a new window that overlaps with a preserved device that is
> downstream of a different bridge.
> 
> [...]

Reviewed-by: Pasha Tatashin <pasha.tatashin at soleen.com>

-- 
Pasha Tatashin <pasha.tatashin at soleen.com>