1*4d2a7bfaSCedric XingWhat: /sys/devices/virtual/misc/tdx_guest/measurements/MRNAME[:HASH] 2*4d2a7bfaSCedric XingDate: April, 2025 3*4d2a7bfaSCedric XingKernelVersion: v6.16 4*4d2a7bfaSCedric XingContact: linux-coco@lists.linux.dev 5*4d2a7bfaSCedric XingDescription: 6*4d2a7bfaSCedric Xing Value of a TDX measurement register (MR). MRNAME and HASH above 7*4d2a7bfaSCedric Xing are placeholders. The optional suffix :HASH is used for MRs 8*4d2a7bfaSCedric Xing that have associated hash algorithms. See below for a complete 9*4d2a7bfaSCedric Xing list of TDX MRs exposed via sysfs. Refer to Intel TDX Module 10*4d2a7bfaSCedric Xing ABI Specification for the definition of TDREPORT and the full 11*4d2a7bfaSCedric Xing list of TDX measurements. 12*4d2a7bfaSCedric Xing 13*4d2a7bfaSCedric Xing Intel TDX Module ABI Specification can be found at: 14*4d2a7bfaSCedric Xing https://www.intel.com/content/www/us/en/developer/tools/trust-domain-extensions/documentation.html#architecture 15*4d2a7bfaSCedric Xing 16*4d2a7bfaSCedric Xing See also: 17*4d2a7bfaSCedric Xing https://docs.kernel.org/driver-api/coco/measurement-registers.html 18*4d2a7bfaSCedric Xing 19*4d2a7bfaSCedric XingWhat: /sys/devices/virtual/misc/tdx_guest/measurements/mrconfigid 20*4d2a7bfaSCedric XingDate: April, 2025 21*4d2a7bfaSCedric XingKernelVersion: v6.16 22*4d2a7bfaSCedric XingContact: linux-coco@lists.linux.dev 23*4d2a7bfaSCedric XingDescription: 24*4d2a7bfaSCedric Xing (RO) MRCONFIGID - 48-byte immutable storage typically used for 25*4d2a7bfaSCedric Xing software-defined ID for non-owner-defined configuration of the 26*4d2a7bfaSCedric Xing guest TD – e.g., run-time or OS configuration. 27*4d2a7bfaSCedric Xing 28*4d2a7bfaSCedric XingWhat: /sys/devices/virtual/misc/tdx_guest/measurements/mrowner 29*4d2a7bfaSCedric XingDate: April, 2025 30*4d2a7bfaSCedric XingKernelVersion: v6.16 31*4d2a7bfaSCedric XingContact: linux-coco@lists.linux.dev 32*4d2a7bfaSCedric XingDescription: 33*4d2a7bfaSCedric Xing (RO) MROWNER - 48-byte immutable storage typically used for 34*4d2a7bfaSCedric Xing software-defined ID for the guest TD’s owner. 35*4d2a7bfaSCedric Xing 36*4d2a7bfaSCedric XingWhat: /sys/devices/virtual/misc/tdx_guest/measurements/mrownerconfig 37*4d2a7bfaSCedric XingDate: April, 2025 38*4d2a7bfaSCedric XingKernelVersion: v6.16 39*4d2a7bfaSCedric XingContact: linux-coco@lists.linux.dev 40*4d2a7bfaSCedric XingDescription: 41*4d2a7bfaSCedric Xing (RO) MROWNERCONFIG - 48-byte immutable storage typically used 42*4d2a7bfaSCedric Xing for software-defined ID for owner-defined configuration of the 43*4d2a7bfaSCedric Xing guest TD – e.g., specific to the workload rather than the 44*4d2a7bfaSCedric Xing run-time or OS. 45*4d2a7bfaSCedric Xing 46*4d2a7bfaSCedric XingWhat: /sys/devices/virtual/misc/tdx_guest/measurements/mrtd:sha384 47*4d2a7bfaSCedric XingDate: April, 2025 48*4d2a7bfaSCedric XingKernelVersion: v6.16 49*4d2a7bfaSCedric XingContact: linux-coco@lists.linux.dev 50*4d2a7bfaSCedric XingDescription: 51*4d2a7bfaSCedric Xing (RO) MRTD - Measurement of the initial contents of the TD. 52*4d2a7bfaSCedric Xing 53*4d2a7bfaSCedric XingWhat: /sys/devices/virtual/misc/tdx_guest/measurements/rtmr[0123]:sha384 54*4d2a7bfaSCedric XingDate: April, 2025 55*4d2a7bfaSCedric XingKernelVersion: v6.16 56*4d2a7bfaSCedric XingContact: linux-coco@lists.linux.dev 57*4d2a7bfaSCedric XingDescription: 58*4d2a7bfaSCedric Xing (RW) RTMR[0123] - 4 Run-Time extendable Measurement Registers. 59*4d2a7bfaSCedric Xing Read from any of these returns the current value of the 60*4d2a7bfaSCedric Xing corresponding RTMR. Write extends the written buffer to the 61*4d2a7bfaSCedric Xing RTMR. All writes must start at offset 0 and be 48 bytes in 62*4d2a7bfaSCedric Xing size. Partial writes will result in EINVAL returned by the 63*4d2a7bfaSCedric Xing write() syscall. 64