On 13/02/2026 14:51, Jan Beulich wrote: > On 13.02.2026 12:37, Oleksii Moisieiev wrote: >> From: Grygorii Strashko <[email protected]> >> >> Add chained handling of assigned DT devices to support access-controller >> functionality through SCI framework, so a DT device assign request can be >> passed to firmware for processing and enabling VM access to the requested >> device (for example, device power management through SCMI). >> >> The SCI access-controller DT device processing is called before the IOMMU >> path. It runs for any DT-described device (protected or not, and even when >> the IOMMU is disabled). The IOMMU path remains unchanged for PCI devices; >> only the DT path is relaxed to permit non-IOMMU devices. >> >> This lets xl.cfg:"dtdev" list both IOMMU-protected and non-protected DT >> devices: >> >> dtdev = [ >> "/soc/video@e6ef0000", <- IOMMU protected device >> "/soc/i2c@e6508000", <- not IOMMU protected device >> ] >> >> The change is done in two parts: >> 1) call sci_do_domctl() in do_domctl() before IOMMU processing. If >> sci_do_domctl() reports an error other than -ENXIO, treat it as >> authoritative and skip the IOMMU path. A return of -ENXIO indicates >> that SCI did not handle the request and is ignored, allowing the >> existing IOMMU handling to run unchanged; >> 2) update iommu_do_dt_domctl() to check for dt_device_is_protected() and >> not fail if DT device is not protected by IOMMU. iommu_do_pci_domctl >> doesn't need to be updated because iommu_do_domctl first tries >> iommu_do_pci_domctl (when CONFIG_HAS_PCI) and falls back to >> iommu_do_dt_domctl only if PCI returns -ENODEV. >> >> The new dt_device_is_protected() bypass in iommu_do_dt_domctl only >> applies to DT-described devices; SCI parameters are carried via DT >> nodes. PCI devices handled by iommu_do_pci_domctl do not carry DT/SCI >> metadata in this path, so there is no notion of “SCI parameters on a >> non-IOMMU-protected PCI device” for it to interpret or to skip. The PCI >> path should continue to report errors if assignment cannot be performed >> by the IOMMU layer. So we should leave iommu_do_pci_domctl unchanged; the >> SCI/DT-specific relaxations belong only in the DT path. Also SCI handling >> only exists when DT is present. >> >> Signed-off-by: Grygorii Strashko <[email protected]> >> Signed-off-by: Oleksii Moisieiev <[email protected]> > Mind me asking where my A-b went? > > Jan Sorry, missed that... :( Will add in the next patch series...
--- Oleksii
