kernel/linux.git/arch/x86/include/asm/shared, branch v7.2-rc1

x86/virt/tdx: Add SEAMCALL wrapper for TDH.SYS.DISABLE

2026-04-27T22:13:38+00:00

Some early TDX-capable platforms have an erratum where a partial write to TDX private memory can cause a machine check on a subsequent read. On these platforms, kexec and kdump have been disabled in these cases, because the old kernel cannot safely hand off TDX state to the new kernel. Later TDX modules support the TDH.SYS.DISABLE SEAMCALL, which provides a way to cleanly disable TDX and allow kexec to proceed. The new SEAMCALL has an enumeration bit, but that is ignored. It is expected that users will be using the latest TDX module, and the failure mode for running the missing SEAMCALL on an older module is not fatal. This can be a long running operation, and the time needed largely depends on the amount of memory that has been allocated to TDs. If all TDs have been destroyed prior to the sys_disable call, then it is fast, with only needing to override the TDX module memory. After the SEAMCALL completes, the TDX module is disabled and all memory resources allocated to TDX are freed and reset. The next kernel can then re-initialize the TDX module from scratch via the normal TDX bring-up sequence. The SEAMCALL can return two different error codes that expect a retry. - TDX_INTERRUPTED_RESUMABLE can be returned in the case of a host interrupt. However, it will not return until it makes some forward progress, so we can expect to complete even in the case of interrupt storms. - TDX_SYS_BUSY will be returned on contention with other TDH.SYS.* SEAMCALLs, however a side effect of TDH.SYS.DISABLE is that it will block other SEAMCALLs once it gets going. So this contention will be short lived. So loop infinitely on either of these error codes, until success or other error. An error is printed if the SEAMCALL fails with anything other than the error codes that cause retries, or 'synthesized' error codes produced for #GP or #UD. e.g., an old module that has been properly initialized, that doesn't implement SYS_DISABLE, returns TDX_OPERAND_INVALID. This prints: virt/tdx: TDH.SYS.DISABLE failed: 0xc000010000000000 But a system that doesn't have any TDX support at all doesn't print anything. Co-developed-by: Rick Edgecombe Signed-off-by: Rick Edgecombe Signed-off-by: Vishal Verma Signed-off-by: Dave Hansen Reviewed-by: Chao Gao Reviewed-by: Kiryl Shutsemau (Meta) Acked-by: Kai Huang Link: https://patch.msgid.link/20260402-fuller_tdx_kexec_support-v3-3-34438d7094bf@intel.com

x86/tdx: Move TDX architectural error codes into

2026-04-27T22:13:38+00:00

Today there are two separate locations where TDX error codes are defined: arch/x86/include/asm/tdx.h arch/x86/kvm/vmx/tdx_errno.h They have some overlap that is already defined similarly. Reduce the duplication by unifying the architectural error codes at: asm/shared/tdx_errno.h ...and update the headers that contained the duplicated definitions to include the new unified header. "asm/shared" is used for sharing TDX code between the early compressed code and the normal kernel code. While the compressed code for the guest doesn't use these error code header definitions today, it does make the types of calls that return the values they define. So place the defines in "shared" location so that it can, but leave such cleanups for future changes. [Rick: enhance log] [Vishal: reduce to a simple move of architectural defines only] Signed-off-by: Kirill A. Shutemov Signed-off-by: Rick Edgecombe Signed-off-by: Vishal Verma Signed-off-by: Dave Hansen Reviewed-by: Chao Gao Acked-by: Sean Christopherson Link: https://patch.msgid.link/20260402-fuller_tdx_kexec_support-v3-1-34438d7094bf@intel.com

x86/tdx: Rename TDX_ATTR_* to TDX_TD_ATTR_*

2026-03-04T00:06:49+00:00

The macros TDX_ATTR_* and DEF_TDX_ATTR_* are related to TD attributes, which are TD-scope attributes. Naming them as TDX_ATTR_* can be somewhat confusing and might mislead people into thinking they are TDX global things. Rename TDX_ATTR_* to TDX_TD_ATTR_* to explicitly clarify they are TD-scope things. Suggested-by: Rick Edgecombe Signed-off-by: Xiaoyao Li Signed-off-by: Dave Hansen Reviewed-by: Rick Edgecombe Reviewed-by: Binbin Wu Reviewed-by: Kiryl Shutsemau Acked-by: Sean Christopherson Link: https://patch.msgid.link/20260303030335.766779-4-xiaoyao.li@intel.com

x86/tdx: Fix the typo in TDX_ATTR_MIGRTABLE

2026-03-04T00:06:49+00:00

The TD scoped TDCS attributes are defined by bit positions. In the guest side of the TDX code, the 'tdx_attributes' string array holds pretty print names for these attributes, which are generated via macros and defines. Today these pretty print names are only used to print the attribute names to dmesg. Unfortunately there is a typo in the define for the migratable bit. Change the defines TDX_ATTR_MIGRTABLE* to TDX_ATTR_MIGRATABLE*. Update the sole user, the tdx_attributes array, to use the fixed name. Since these defines control the string printed to dmesg, the change is user visible. But the risk of breakage is almost zero since it is not exposed in any interface expected to be consumed programmatically. Fixes: 564ea84c8c14 ("x86/tdx: Dump attributes and TD_CTLS on boot") Signed-off-by: Xiaoyao Li Signed-off-by: Dave Hansen Reviewed-by: Kirill A. Shutemov Reviewed-by: Kai Huang Acked-by: Sean Christopherson Link: https://patch.msgid.link/20260303030335.766779-2-xiaoyao.li@intel.com

x86/boot: Move boot_*msr helpers to asm/shared/msr.h

2025-10-30T15:29:53+00:00

The boot_{rdmsr,wrmsr}() helpers are *just* the barebones MSR access functionality, without any tracing or exception handling glue as it is done in kernel proper. Move these helpers to asm/shared/msr.h and rename to raw_{rdmsr,wrmsr}() to indicate what they are. [ bp: Correct the reason why those helpers exist. I should've caught that in the original patch that added them: 176db622573f ("x86/boot: Introduce helpers for MSR reads/writes" but oh well... - fixup include path delimiters to <> ] Signed-off-by: John Allen Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Tom Lendacky Link: https://patch.msgid.link/all/20250924200852.4452-2-john.allen@amd.com

KVM: TDX: Exit to userspace for SetupEventNotifyInterrupt

2025-06-20T18:09:50+00:00

Signed-off-by: Paolo Bonzini

KVM: TDX: Add new TDVMCALL status code for unsupported subfuncs

2025-06-20T17:09:31+00:00

Add the new TDVMCALL status code TDVMCALL_STATUS_SUBFUNC_UNSUPPORTED and return it for unimplemented TDVMCALL subfunctions. Returning TDVMCALL_STATUS_INVALID_OPERAND when a subfunction is not implemented is vague because TDX guests can't tell the error is due to the subfunction is not supported or an invalid input of the subfunction. New GHCI spec adds TDVMCALL_STATUS_SUBFUNC_UNSUPPORTED to avoid the ambiguity. Use it instead of TDVMCALL_STATUS_INVALID_OPERAND. Before the change, for common guest implementations, when a TDX guest receives TDVMCALL_STATUS_INVALID_OPERAND, it has two cases: 1. Some operand is invalid. It could change the operand to another value retry. 2. The subfunction is not supported. For case 1, an invalid operand usually means the guest implementation bug. Since the TDX guest can't tell which case is, the best practice for handling TDVMCALL_STATUS_INVALID_OPERAND is stopping calling such leaf, treating the failure as fatal if the TDVMCALL is essential or ignoring it if the TDVMCALL is optional. With this change, TDVMCALL_STATUS_SUBFUNC_UNSUPPORTED could be sent to old TDX guest that do not know about it, but it is expected that the guest will make the same action as TDVMCALL_STATUS_INVALID_OPERAND. Currently, no known TDX guest checks TDVMCALL_STATUS_INVALID_OPERAND specifically; for example Linux just checks for success. Signed-off-by: Binbin Wu [Return it for untrapped KVM_HC_MAP_GPA_RANGE. - Paolo] Signed-off-by: Paolo Bonzini

Merge tag 'tsm-for-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/devsec/tsm

2025-05-30T04:21:11+00:00

Pull trusted security manager (TSM) updates from Dan Williams: - Add a general sysfs scheme for publishing "Measurement" values provided by the architecture's TEE Security Manager. Use it to publish TDX "Runtime Measurement Registers" ("RTMRs") that either maintain a hash of stored values (similar to a TPM PCR) or provide statically provisioned data. These measurements are validated by a relying party. - Reorganize the drivers/virt/coco/ directory for "host" and "guest" shared infrastructure. - Fix a configfs-tsm-report unregister bug - With CONFIG_TSM_MEASUREMENTS joining CONFIG_TSM_REPORTS and in anticipation of more shared "TSM" infrastructure arriving, rename the maintainer entry to "TRUSTED SECURITY MODULE (TSM) INFRASTRUCTURE". * tag 'tsm-for-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/devsec/tsm: tsm-mr: Fix init breakage after bin_attrs constification by scoping non-const pointers to init phase sample/tsm-mr: Fix missing static for sample_report virt: tdx-guest: Transition to scoped_cond_guard for mutex operations virt: tdx-guest: Refactor and streamline TDREPORT generation virt: tdx-guest: Expose TDX MRs as sysfs attributes x86/tdx: tdx_mcall_get_report0: Return -EBUSY on TDCALL_OPERAND_BUSY error x86/tdx: Add tdx_mcall_extend_rtmr() interface tsm-mr: Add tsm-mr sample code tsm-mr: Add TVM Measurement Register support configfs-tsm-report: Fix NULL dereference of tsm_ops coco/guest: Move shared guest CC infrastructure to drivers/virt/coco/guest/ configfs-tsm: Namespace TSM report symbols

x86/tdx: Add tdx_mcall_extend_rtmr() interface

2025-05-09T02:17:43+00:00

The TDX guest exposes one MRTD (Build-time Measurement Register) and four RTMR (Run-time Measurement Register) registers to record the build and boot measurements of a virtual machine (VM). These registers are similar to PCR (Platform Configuration Register) registers in the TPM (Trusted Platform Module) space. This measurement data is used to implement security features like attestation and trusted boot. To facilitate updating the RTMR registers, the TDX module provides support for the `TDG.MR.RTMR.EXTEND` TDCALL which can be used to securely extend the RTMR registers. Add helper function to update RTMR registers. It will be used by the TDX guest driver in enabling RTMR extension support. Co-developed-by: Kuppuswamy Sathyanarayanan Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Cedric Xing Acked-by: Dionna Amalie Glaze Acked-by: Dave Hansen Link: https://patch.msgid.link/20250506-tdx-rtmr-v6-3-ac6ff5e9d58a@intel.com Signed-off-by: Dan Williams

Merge branch 'kvm-tdx-initial' into HEAD

2025-04-07T11:36:33+00:00

This large commit contains the initial support for TDX in KVM. All x86 parts enable the host-side hypercalls that KVM uses to talk to the TDX module, a software component that runs in a special CPU mode called SEAM (Secure Arbitration Mode). The series is in turn split into multiple sub-series, each with a separate merge commit: - Initialization: basic setup for using the TDX module from KVM, plus ioctls to create TDX VMs and vCPUs. - MMU: in TDX, private and shared halves of the address space are mapped by different EPT roots, and the private half is managed by the TDX module. Using the support that was added to the generic MMU code in 6.14, add support for TDX's secure page tables to the Intel side of KVM. Generic KVM code takes care of maintaining a mirror of the secure page tables so that they can be queried efficiently, and ensuring that changes are applied to both the mirror and the secure EPT. - vCPU enter/exit: implement the callbacks that handle the entry of a TDX vCPU (via the SEAMCALL TDH.VP.ENTER) and the corresponding save/restore of host state. - Userspace exits: introduce support for guest TDVMCALLs that KVM forwards to userspace. These correspond to the usual KVM_EXIT_* "heavyweight vmexits" but are triggered through a different mechanism, similar to VMGEXIT for SEV-ES and SEV-SNP. - Interrupt handling: support for virtual interrupt injection as well as handling VM-Exits that are caused by vectored events. Exclusive to TDX are machine-check SMIs, which the kernel already knows how to handle through the kernel machine check handler (commit 7911f145de5f, "x86/mce: Implement recovery for errors in TDX/SEAM non-root mode") - Loose ends: handling of the remaining exits from the TDX module, including EPT violation/misconfig and several TDVMCALL leaves that are handled in the kernel (CPUID, HLT, RDMSR/WRMSR, GetTdVmCallInfo); plus returning an error or ignoring operations that are not supported by TDX guests Signed-off-by: Paolo Bonzini