On 2026-02-25 04:47 PM, Bjorn Helgaas wrote: > On Thu, Jan 29, 2026 at 09:24:50PM +0000, David Matlack wrote: > > Inherit bus numbers from the previous kernel during a Live Update when > > one or more PCI devices are being preserved. This is necessary so that > > preserved devices can DMA through the IOMMU during a Live Update > > (changing bus numbers would break IOMMU translation). > > I think changing bus numbers would break DMA regardless of whether an > IOMMU is involved. Completions carrying the data for DMA reads are > routed back to the Requester ID of the read.
Ahh, makes sense. I'll clarify the commit message in the next version.
