linux-kernel - [PATCH 0/2] iommu: MSI parent domain conversion

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <cover.1750858125.git.namcao@linutronix.de>
Date: Thu, 26 Jun 2025 16:48:53 +0200
From: Nam Cao <namcao@...utronix.de>
To: Marc Zyngier <maz@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Joerg Roedel <joro@...tes.org>,
	Will Deacon <will@...nel.org>,
	Robin Murphy <robin.murphy@....com>,
	Suravee Suthikulpanit <suravee.suthikulpanit@....com>,
	David Woodhouse <dwmw2@...radead.org>,
	Lu Baolu <baolu.lu@...ux.intel.com>,
	iommu@...ts.linux.dev,
	linux-kernel@...r.kernel.org
Cc: Nam Cao <namcao@...utronix.de>
Subject: [PATCH 0/2] iommu: MSI parent domain conversion

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 convert the IOMMU drivers to implement MSI parent domain.

 drivers/iommu/Kconfig               |  1 +
 drivers/iommu/amd/Kconfig           |  1 +
 drivers/iommu/amd/iommu.c           | 26 ++++++++++++++------------
 drivers/iommu/intel/irq_remapping.c | 28 ++++++++++++++--------------
 4 files changed, 30 insertions(+), 26 deletions(-)

-- 
2.39.5