Subject: [RFC PATCH v4 00/14] coco/TSM: Host-side Arm CCA IDE setup via connect/disconnect callbacks

From: "Aneesh Kumar K.V (Arm)" <[email-masked]>
Date: Mon, 27 Apr 2026 12:21:07 +0530

This patch series implements the TSM ->connect() and ->disconnect() callbacks
required for the Arm CCA IDE setup as per the RMM 2.0bet1 specification [1].

This patchset includes the host-side flow needed by connect/disconnect,
including:
- DA feature detection helpers
- host TSM callback wiring and IDE stream allocation support
- creation/registration of RMM pdev descriptors
- RMM pdev communication helpers
- pdev stop and teardown helpers for disconnect
- pdev instantiation from the connect path
- public key registration with RMM

To support public-key handling from the device certificate chain, the series
also includes the required X.509 parser updates.

The series builds upon the TSM framework patches posted at [2] and depends on
the KVM CCA patchset [3]. A git repository containing all the related changes is
available at [4].

Testing / Usage

To initiate the IDE setup:
	echo tsm0 > /sys/bus/pci/devices/$DEVICE/tsm/connect

To disconnect:
	echo tsm0 > /sys/bus/pci/devices/$DEVICE/tsm/disconnect

Changes from v3:
https://lore.kernel.org/all/[email-masked]
* updated the patches to follow the RMM 2.0bet1 specification
* reworked the host-side pdev lifecycle to better match the RMM 2.0bet1 flow,
  including common pdev state, root-port pdev support, and non-coherent stream
  setup and teardown
* split PF0 setup into identity collection and conditional public-key
  installation, and gate DA enablement on RMI_FEATURE_REGISTER_2_DA
* added coordinated handling for RMI_DEV_COMM_EXIT_STREAM_WAIT, along with
  stream connect/disconnect and stream key refresh/purge support during vdev
  teardown

Changes from v2:
rfc-v2 https://lore.kernel.org/all/[email-masked]
* rebase to latest kernel and core TSM changes
* Address review feedback.

v1:
rfc-v1 https://lore.kernel.org/all/[email-masked]

[1] https://developer.arm.com/documentation/den0137/2-0bet1/
[2] https://lore.kernel.org/all/[email-masked]
[3] https://lore.kernel.org/all/[email-masked]
[4] https://gitlab.arm.com/linux-arm/linux-cca.git cca/topics/cca-tdisp-upstream-rfc-v4

Cc: Alexey Kardashevskiy <[email-masked]>
Cc: Catalin Marinas <[email-masked]>
Cc: Dan Williams <[email-masked]>
Cc: Jason Gunthorpe <[email-masked]>
Cc: Jonathan Cameron <[email-masked]>
Cc: Marc Zyngier <[email-masked]>
Cc: Samuel Ortiz <[email-masked]>
Cc: Steven Price <[email-masked]>
Cc: Suzuki K Poulose <[email-masked]>
Cc: Will Deacon <[email-masked]>
Cc: Xu Yilun <[email-masked]>

Aneesh Kumar K.V (Arm) (11):
  coco: host: arm64: Add host TSM callback and IDE stream allocation
    support
  coco: host: arm64: Create RMM pdev objects for PCI endpoints
  coco: host: arm64: Add RMM device communication helpers
  coco: host: arm64: Add helper to stop and tear down an RMM pdev
  coco: host: arm64: Register device public key with RMM
  coco: host: arm64: Initialize RMM pdev state for TDISP IDE connect
  coco: host: arm64: Coordinate peer stream waits during pdev
    communication
  coco: host: arm64: Connect RMM pdev streams for IDE devices
  coco: host: arm64: Refcount root-port pdevs used by IDE streams
  PCI/TSM: Move CMA DOE mailbox discovery out of
    pci_tsm_pf0_constructor()
  coco: host: arm64: Add NCOH_SYS stream support for RC endpoints

Lukas Wunner (3):
  X.509: Make certificate parser public
  X.509: Parse Subject Alternative Name in certificates
  X.509: Move certificate length retrieval into new helper

 arch/arm64/include/asm/rmi_cmds.h         |  85 +++
 arch/arm64/include/asm/rmi_smc.h          | 168 +++++
 crypto/asymmetric_keys/x509_cert_parser.c |   9 +
 crypto/asymmetric_keys/x509_loader.c      |  38 +-
 crypto/asymmetric_keys/x509_parser.h      |  42 +-
 drivers/crypto/ccp/sev-dev-tsm.c          |  13 +
 drivers/firmware/smccc/rmm.c              |  12 +
 drivers/firmware/smccc/rmm.h              |   8 +
 drivers/firmware/smccc/smccc.c            |   1 +
 drivers/pci/tsm/core.c                    |  14 +-
 drivers/virt/coco/Kconfig                 |   2 +
 drivers/virt/coco/Makefile                |   1 +
 drivers/virt/coco/arm-cca-host/Kconfig    |  23 +
 drivers/virt/coco/arm-cca-host/Makefile   |   5 +
 drivers/virt/coco/arm-cca-host/arm-cca.c  | 494 ++++++++++++
 drivers/virt/coco/arm-cca-host/rmi-da.c   | 867 ++++++++++++++++++++++
 drivers/virt/coco/arm-cca-host/rmi-da.h   | 217 ++++++
 drivers/virt/coco/tdx-host/tdx-host.c     |  13 +
 include/keys/asymmetric-type.h            |   2 +
 include/keys/x509-parser.h                |  57 ++
 20 files changed, 2012 insertions(+), 59 deletions(-)
 create mode 100644 drivers/virt/coco/arm-cca-host/Kconfig
 create mode 100644 drivers/virt/coco/arm-cca-host/Makefile
 create mode 100644 drivers/virt/coco/arm-cca-host/arm-cca.c
 create mode 100644 drivers/virt/coco/arm-cca-host/rmi-da.c
 create mode 100644 drivers/virt/coco/arm-cca-host/rmi-da.h
 create mode 100644 include/keys/x509-parser.h

-- 
2.43.0