Changes in Kconfig

59783353467958517a3e511394d7ab3aed03bc6a - coco/tdx-host: Introduce a "tdx_host" device

Thu, 21 May 2026 00:28:52 +0200

coco/tdx-host: Introduce a "tdx_host" deviceTDX depends on a platform firmware module that runs on the CPU.Unlike other CoCo architectures, TDX has no hardware "device"running the show, just a blob on the CPU.Create a virtual device to anchor interactions with this platformfirmware. This lets later code: - expose metadata: TDX module version, seamldr version, to userspace as device attributes - implement firmware uploader APIs (which are tied to a device) to support TDX module runtime updatesUse a faux device because the TDX module is singular within the systemand has no platform resources. Using a faux device eliminates the needto create a stub bus.The call to tdx_get_sysinfo() ensures that the TDX module is ready toprovide services.Note that AMD has a PCI device for the PSP for SEV and ARM CCA willlikely have a faux device [1].Thanks to Dan and Yilun for all the help on this one.[ dhansen: trim changelog ]Signed-off-by: Chao Gao Signed-off-by: Dave Hansen Reviewed-by: Jonathan Cameron Reviewed-by: Tony Lindgren Reviewed-by: Xu Yilun Reviewed-by: Kai Huang Reviewed-by: Kiryl Shutsemau (Meta) Reviewed-by: Xiaoyao Li Link: https://lore.kernel.org/all/2025073035-bulginess-rematch-b92e@gregkh/ # [1]Link: https://patch.msgid.link/20260520133909.409394-7-chao.gao@intel.com List of files: /linux/drivers/virt/coco/Kconfig

311607017e13d087161586e1d6cf28bb3a0ca942 - virt: Fix Kconfig warning when selecting TSM without VIRT_DRIVERS

Wed, 03 Dec 2025 23:25:07 +0100

virt: Fix Kconfig warning when selecting TSM without VIRT_DRIVERSAfter commit 3225f52cde56 ("PCI/TSM: Establish Secure Sessions and LinkEncryption"), there is a Kconfig warning when selecting CONFIG_TSMwithout CONFIG_VIRT_DRIVERS: WARNING: unmet direct dependencies detected for TSM Depends on [n]: VIRT_DRIVERS [=n] Selected by [y]: - PCI_TSM [=y] && PCI [=y]CONFIG_TSM is defined in drivers/virt/coco/Kconfig but this Kconfig isonly sourced when CONFIG_VIRT_DRIVERS is enabled. Since this symbol ishidden with no dependencies, it should be available without a symbolthat just enables a menu.Move the sourcing of drivers/virt/coco/Kconfig outside ofCONFIG_VIRT_DRIVERS and wrap the other source statements indrivers/virt/coco/Kconfig with CONFIG_VIRT_DRIVERS to ensure users donot get any additional prompts while ensuring CONFIG_TSM is alwaysavailable to select. This complements commit 110c155e8a68 ("drivers/virt:Drop VIRT_DRIVERS build dependency"), which addressed the build issuethat this Kconfig warning was pointing out.Fixes: 3225f52cde56 ("PCI/TSM: Establish Secure Sessions and Link Encryption")Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202511140712.NubhamPy-lkp@intel.com/Signed-off-by: Nathan Chancellor Link: https://patch.msgid.link/20251203-fix-pci-tsm-select-tsm-warning-v1-1-c3959c1cb110@kernel.orgSigned-off-by: Dan Williams List of files: /linux/drivers/virt/coco/Kconfig

603c646f001008eaf8b5a7a888043e5cc8c494a2 - coco/tsm: Introduce a core device for TEE Security Managers

Fri, 31 Oct 2025 22:28:53 +0100

coco/tsm: Introduce a core device for TEE Security ManagersA "TSM" is a platform component that provides an API for securelyprovisioning resources for a confidential guest (TVM) to consume. Thename originates from the PCI specification for platform agent thatcarries out operations for PCIe TDISP (TEE Device Interface SecurityProtocol).Instances of this core device are parented by a device representing theplatform security function like CONFIG_CRYPTO_DEV_CCP orCONFIG_INTEL_TDX_HOST.This device interface is a frontend to the aspects of a TSM and TEE I/Othat are cross-architecture common. This includes mechanisms likeenumerating available platform TEE I/O capabilities and provisioningconnections between the platform TSM and device DSMs (Device SecurityManager (TDISP)).For now this is just the scaffolding for registering a TSM device sysfsinterface.Cc: Xu Yilun Reviewed-by: Jonathan Cameron Co-developed-by: Aneesh Kumar K.V (Arm) Signed-off-by: Aneesh Kumar K.V (Arm) Acked-by: Bjorn Helgaas Reviewed-by: Alexey Kardashevskiy Link: https://patch.msgid.link/20251031212902.2256310-2-dan.j.williams@intel.comSigned-off-by: Dan Williams List of files: /linux/drivers/virt/coco/Kconfig

7515f45c165269b72ee739e6fc26cc2ef928fc1b - coco/guest: Move shared guest CC infrastructure to drivers/virt/coco/guest/

Tue, 04 Mar 2025 08:14:26 +0100

coco/guest: Move shared guest CC infrastructure to drivers/virt/coco/guest/In preparation for creating a new drivers/virt/coco/host/ directory tohouse shared host driver infrastructure for confidential computing, moveconfigfs-tsm to a guest/ sub-directory. The tsm.ko module is renamed totsm_reports.ko. The old tsm.ko module was only ever demand loaded bykernel internal dependencies, so it should not affect existing userspacemodule install scripts.The new drivers/virt/coco/guest/ is also a preparatory landing spot fornew / optional TSM Report mechanics like a TCB stability enumeration /watchdog mechanism. To be added later.Cc: Wu Hao Cc: Yilun Xu Cc: Samuel Ortiz Cc: Tom Lendacky Reviewed-by: Alexey Kardashevskiy Reviewed-by: Kuppuswamy Sathyanarayanan Link: https://patch.msgid.link/174107246641.1288555.208426916259466774.stgit@dwillia2-xfh.jf.intel.comSigned-off-by: Dan Williams List of files: /linux/drivers/virt/coco/Kconfig

7999edc484ca376f803562edb2d43ec921642c2a - virt: arm-cca-guest: TSM_REPORT support for realms

Thu, 17 Oct 2024 15:14:33 +0200

virt: arm-cca-guest: TSM_REPORT support for realmsIntroduce an arm-cca-guest driver that registers withthe configfs-tsm module to provide user interfaces forretrieving an attestation token.When a new report is requested the arm-cca-guest driverinvokes the appropriate RSI interfaces to query anattestation token.The steps to retrieve an attestation token are as follows: 1. Mount the configfs filesystem if not already mounted mount -t configfs none /sys/kernel/config 2. Generate an attestation token report=/sys/kernel/config/tsm/report/report0 mkdir $report dd if=/dev/urandom bs=64 count=1 > $report/inblob hexdump -C $report/outblob rmdir $reportSigned-off-by: Sami Mujawar Signed-off-by: Suzuki K Poulose Signed-off-by: Steven Price Reviewed-by: Gavin Shan Link: https://lore.kernel.org/r/20241017131434.40935-11-steven.price@arm.comSigned-off-by: Catalin Marinas List of files: /linux/drivers/virt/coco/Kconfig

a06c3fad49a50d5d5eb078f93e70f4d3eca5d5a5 - drivers/virt: pkvm: Add initial support for running as a protected guest

Fri, 30 Aug 2024 15:01:45 +0200

drivers/virt: pkvm: Add initial support for running as a protected guestImplement a pKVM protected guest driver to probe the presence of pKVMand determine the memory protection granule using the HYP_MEMINFOhypercall.Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20240830130150.8568-3-will@kernel.orgSigned-off-by: Will Deacon List of files: /linux/drivers/virt/coco/Kconfig

70e6f7e2b98575621019aa40ac616be58ff984e0 - configfs-tsm: Introduce a shared ABI for attestation reports

Tue, 26 Sep 2023 05:13:29 +0200

configfs-tsm: Introduce a shared ABI for attestation reportsOne of the common operations of a TSM (Trusted Security Module) is toprovide a way for a TVM (confidential computing guest executionenvironment) to take a measurement of its launch state, sign it andsubmit it to a verifying party. Upon successful attestation thatverifies the integrity of the TVM additional secrets may be deployed.The concept is common across TSMs, but the implementations areunfortunately vendor specific. While the industry grapples with a commondefinition of this attestation format [1], Linux need not make thisproblem worse by defining a new ABI per TSM that wants to perform asimilar operation. The current momentum has been to invent new ioctl-ABIper TSM per function which at best is an abdication of the kernel'sresponsibility to make common infrastructure concepts share common ABI.The proposal, targeted to conceptually work with TDX, SEV-SNP, COVE ifnot more, is to define a configfs interface to retrieve the TSM-specificblob. report=/sys/kernel/config/tsm/report/report0 mkdir $report dd if=binary_userdata_plus_nonce > $report/inblob hexdump $report/outblobThis approach later allows for the standardization of the attestationblob format without needing to invent a new ABI. Once standardizationhappens the standard format can be emitted by $report/outblob andindicated by $report/provider, or a new attribute like"$report/tcg_coco_report" can emit the standard format alongside thevendor format.Review of previous iterations of this interface identified that there isa need to scale report generation for multiple container environments[2]. Configfs enables a model where each container can bind mount one ormore report generation item instances. Still, within a container only asingle thread can be manipulating a given configuration instance at atime. A 'generation' count is provided to detect conflicts betweenmultiple threads racing to configure a report instance.The SEV-SNP concepts of "extended reports" and "privilege levels" areoptionally enabled by selecting 'tsm_report_ext_type' at register_tsm()time. The expectation is that those concepts are generic enough thatthey may be adopted by other TSM implementations. In other words,configfs-tsm aims to address a superset of TSM specific functionalitywith a common ABI where attributes may appear, or not appear, based onthe set of concepts the implementation supports.Link: http://lore.kernel.org/r/64961c3baf8ce_142af829436@dwillia2-xfh.jf.intel.com.notmuch [1]Link: http://lore.kernel.org/r/57f3a05e-8fcd-4656-beea-56bb8365ae64@linux.microsoft.com [2]Cc: Kuppuswamy Sathyanarayanan Cc: Dionna Amalie Glaze Cc: James Bottomley Cc: Peter Gonda Cc: Greg Kroah-Hartman Cc: Samuel Ortiz Acked-by: Greg Kroah-Hartman Acked-by: Thomas Gleixner Reviewed-by: Kuppuswamy Sathyanarayanan Tested-by: Kuppuswamy Sathyanarayanan Reviewed-by: Tom Lendacky Signed-off-by: Dan Williams List of files: /linux/drivers/virt/coco/Kconfig

ec51ffcf263016111f090b9440a3c5a8338648e8 - virt: coco: Add a coco/Makefile and coco/Kconfig

Sun, 13 Aug 2023 02:21:00 +0200

virt: coco: Add a coco/Makefile and coco/KconfigIn preparation for adding another coco build target, relievedrivers/virt/Makefile of the responsibility to track new compilationunit additions to drivers/virt/coco/, and do the same fordrivers/virt/Kconfig.Reviewed-by: Kuppuswamy Sathyanarayanan Tested-by: Kuppuswamy Sathyanarayanan Reviewed-by: Tom Lendacky Signed-off-by: Dan Williams List of files: /linux/drivers/virt/coco/Kconfig