Re: [PATCH 00/16] PCI: MSI parent domain conversion

Manivannan Sadhasivam
2025-07-07T08:28:04Z

On Thu, Jun 26, 2025 at 04:47:50PM GMT, Nam Cao wrote:
> The initial implementation of PCI/MSI interrupt domains in the hierarchical
> interrupt domain model used a shortcut by providing a global PCI/MSI
> domain.
>
> This works because the PCI/MSI[X] hardware is standardized and uniform, but
> it violates the basic design principle of hierarchical interrupt domains:
> Each hardware block involved in the interrupt delivery chain should have a
> separate interrupt domain.
>
> For PCI/MSI[X], the interrupt controller is per PCI device and not a global
> made-up entity.
>
> Unsurprisingly, the shortcut turned out to have downsides as it does not
> allow dynamic allocation of interrupt vectors after initialization and it
> prevents supporting IMS on PCI. For further details, see:
>
> https://lore.kernel.org/lkml/20221111120501.026511281@linutronix.de/
>
> The solution is implementing per device MSI domains, this means the
> entities which provide global PCI/MSI domain so far have to implement MSI
> parent domain functionality instead.
>
> This series converts the PCI controller drivers to implement MSI parent
> domain.
>

Applied the series except patch 14/16 to pci/controller/msi-parent, thanks!

- Mani

> drivers/pci/Kconfig | 1 +
> drivers/pci/controller/Kconfig | 11 +
> drivers/pci/controller/dwc/Kconfig | 1 +
> .../pci/controller/dwc/pcie-designware-host.c | 68 ++----
> drivers/pci/controller/dwc/pcie-designware.h | 1 -
> drivers/pci/controller/mobiveil/Kconfig | 1 +
> .../controller/mobiveil/pcie-mobiveil-host.c | 42 ++--
> .../pci/controller/mobiveil/pcie-mobiveil.h | 1 -
> drivers/pci/controller/pci-aardvark.c | 59 ++---
> drivers/pci/controller/pci-hyperv.c | 98 ++++++--
> drivers/pci/controller/pcie-altera-msi.c | 44 ++--
> drivers/pci/controller/pcie-brcmstb.c | 44 ++--
> drivers/pci/controller/pcie-iproc-msi.c | 45 ++--
> drivers/pci/controller/pcie-mediatek-gen3.c | 67 ++---
> drivers/pci/controller/pcie-mediatek.c | 46 ++--
> drivers/pci/controller/pcie-rcar-host.c | 69 ++----
> drivers/pci/controller/pcie-xilinx-dma-pl.c | 48 ++--
> drivers/pci/controller/pcie-xilinx-nwl.c | 45 ++--
> drivers/pci/controller/pcie-xilinx.c | 55 +++--
> drivers/pci/controller/plda/Kconfig | 1 +
> drivers/pci/controller/plda/pcie-plda-host.c | 44 ++--
> drivers/pci/controller/plda/pcie-plda.h | 1 -
> drivers/pci/controller/vmd.c | 229 +++++++++---------
> 23 files changed, 504 insertions(+), 517 deletions(-)
>
> --
> 2.39.5
>

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