On Thu, Nov 03, 2022 at 08:23:55PM -0700, Kuppuswamy Sathyanarayanan wrote: > Attestation is used to verify the trustworthiness of a TDX guest. > During the guest bring-up, the Intel TDX module measures and records > the initial contents and configuration of the guest, and at runtime, > guest software uses runtime measurement registers (RMTRs) to measure > and record details related to kernel image, command line params, ACPI > tables, initrd, etc. At guest runtime, the attestation process is used > to attest to these measurements. > > The first step in the TDX attestation process is to get the TDREPORT > data. It is a fixed size data structure generated by the TDX module > which includes the above mentioned measurements data, a MAC ID to > protect the integrity of the TDREPORT, and a 64-Byte of user specified > data passed during TDREPORT request which can uniquely identify the > TDREPORT. > > Intel's TDX guest driver exposes TDX_CMD_GET_REPORT IOCTL interface to > enable guest userspace to get the TDREPORT. > > Add a kernel self test module to test this ABI and verify the validity > of the generated TDREPORT. > > Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx> > Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> > Acked-by: Kai Huang <kai.huang@xxxxxxxxx> > Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> > --- > > Changes since v16: > * Modified the code to adapt to fixed size reportdata and tdeport > buffers in struct tdx_report_req. > > Changes since v15: > * None > > Changes since v14: > * Fixed format issue in struct comments. > * Rebased on top of v6.1-rc1 > > Changes since v13: > * Removed __packed from TDREPORT structs. > * Since the guest driver is moved to drivers/virt/coco, removed > tools/arch/x86/include header folder usage. > * Fixed struct comments to match kernel-doc format. > * Fixed commit log as per review comments. > * Fixed some format issues in the code. > > Changes since v12: > * Changed #ifdef DEBUG usage with if (DEBUG). > * Initialized reserved entries values to zero. > > Changes since v11: > * Renamed devname with TDX_GUEST_DEVNAME. > > Changes since v10: > * Replaced TD/TD Guest usage with guest or TDX guest. > * Reworded the subject line. > > Changes since v9: > * Copied arch/x86/include/uapi/asm/tdx.h to tools/arch/x86/include to > decouple header dependency between kernel source and tools dir. > * Fixed Makefile to adapt to above change. > * Fixed commit log and comments. > * Added __packed to hardware structs. > > Changes since v8: > * Please refer to https://lore.kernel.org/all/ \ > 20220728034420.648314-1-sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx/ > > tools/testing/selftests/Makefile | 1 + > tools/testing/selftests/tdx/Makefile | 7 + > tools/testing/selftests/tdx/config | 1 + > tools/testing/selftests/tdx/tdx_guest_test.c | 163 +++++++++++++++++++ > 4 files changed, 172 insertions(+) > create mode 100644 tools/testing/selftests/tdx/Makefile > create mode 100644 tools/testing/selftests/tdx/config > create mode 100644 tools/testing/selftests/tdx/tdx_guest_test.c > > diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile > index 0464b2c6c1e4..f60e14d16bfd 100644 > --- a/tools/testing/selftests/Makefile > +++ b/tools/testing/selftests/Makefile > @@ -73,6 +73,7 @@ TARGETS += sync > TARGETS += syscall_user_dispatch > TARGETS += sysctl > TARGETS += tc-testing > +TARGETS += tdx > TARGETS += timens > ifneq (1, $(quicktest)) > TARGETS += timers > diff --git a/tools/testing/selftests/tdx/Makefile b/tools/testing/selftests/tdx/Makefile > new file mode 100644 > index 000000000000..8dd43517cd55 > --- /dev/null > +++ b/tools/testing/selftests/tdx/Makefile > @@ -0,0 +1,7 @@ > +# SPDX-License-Identifier: GPL-2.0 > + > +CFLAGS += -O3 -Wl,-no-as-needed -Wall -static > + > +TEST_GEN_PROGS := tdx_guest_test > + > +include ../lib.mk > diff --git a/tools/testing/selftests/tdx/config b/tools/testing/selftests/tdx/config > new file mode 100644 > index 000000000000..aa1edc829ab6 > --- /dev/null > +++ b/tools/testing/selftests/tdx/config > @@ -0,0 +1 @@ > +CONFIG_TDX_GUEST_DRIVER=y > diff --git a/tools/testing/selftests/tdx/tdx_guest_test.c b/tools/testing/selftests/tdx/tdx_guest_test.c > new file mode 100644 > index 000000000000..6f7ab667b8cc > --- /dev/null > +++ b/tools/testing/selftests/tdx/tdx_guest_test.c > @@ -0,0 +1,163 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Test TDX guest features > + * > + * Copyright (C) 2022 Intel Corporation. > + * > + * Author: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> > + */ > + > +#include <sys/ioctl.h> > + > +#include <errno.h> > +#include <fcntl.h> > + > +#include "../kselftest_harness.h" > +#include "../../../../include/uapi/linux/tdx-guest.h" > + > +#define TDX_GUEST_DEVNAME "/dev/tdx_guest" > +#define HEX_DUMP_SIZE 8 > +#define DEBUG 0 > + > +/** > + * struct tdreport_type - Type header of TDREPORT_STRUCT. > + * @type: Type of the TDREPORT (0 - SGX, 81 - TDX, rest are reserved) > + * @sub_type: Subtype of the TDREPORT (Default value is 0). > + * @version: TDREPORT version (Default value is 0). > + * @reserved: Added for future extension. > + * > + * More details can be found in TDX v1.0 module specification, sec > + * titled "REPORTTYPE". > + */ > +struct tdreport_type { > + __u8 type; > + __u8 sub_type; > + __u8 version; > + __u8 reserved; > +}; > + > +/** > + * struct reportmac - TDX guest report data, MAC and TEE hashes. > + * @type: TDREPORT type header. > + * @reserved1: Reserved for future extension. > + * @cpu_svn: CPU security version. > + * @tee_tcb_info_hash: SHA384 hash of TEE TCB INFO. > + * @tee_td_info_hash: SHA384 hash of TDINFO_STRUCT. > + * @reportdata: User defined unique data passed in TDG.MR.REPORT request. > + * @reserved2: Reserved for future extension. > + * @mac: CPU MAC ID. > + * > + * It is MAC-protected and contains hashes of the remainder of the > + * report structure along with user provided report data. More details can > + * be found in TDX v1.0 Module specification, sec titled "REPORTMACSTRUCT" > + */ > +struct reportmac { > + struct tdreport_type type; > + __u8 reserved1[12]; > + __u8 cpu_svn[16]; > + __u8 tee_tcb_info_hash[48]; > + __u8 tee_td_info_hash[48]; > + __u8 reportdata[64]; > + __u8 reserved2[32]; > + __u8 mac[32]; > +}; > + > +/** > + * struct td_info - TDX guest measurements and configuration. > + * @attr: TDX Guest attributes (like debug, spet_disable, etc). > + * @xfam: Extended features allowed mask. > + * @mrtd: Build time measurement register. > + * @mrconfigid: Software-defined ID for non-owner-defined configuration > + * of the guest - e.g., run-time or OS configuration. > + * @mrowner: Software-defined ID for the guest owner. > + * @mrownerconfig: Software-defined ID for owner-defined configuration of > + * the guest - e.g., specific to the workload. > + * @rtmr: Run time measurement registers. > + * @reserved: Added for future extension. > + * > + * It contains the measurements and initial configuration of the TDX guest > + * that was locked at initialization and a set of measurement registers > + * that are run-time extendable. More details can be found in TDX v1.0 > + * Module specification, sec titled "TDINFO_STRUCT". > + */ > +struct td_info { > + __u8 attr[8]; > + __u64 xfam; > + __u64 mrtd[6]; > + __u64 mrconfigid[6]; > + __u64 mrowner[6]; > + __u64 mrownerconfig[6]; > + __u64 rtmr[24]; > + __u64 reserved[14]; > +}; > + > +/* > + * struct tdreport - Output of TDCALL[TDG.MR.REPORT]. > + * @reportmac: Mac protected header of size 256 bytes. > + * @tee_tcb_info: Additional attestable elements in the TCB are not > + * reflected in the reportmac. > + * @reserved: Added for future extension. > + * @tdinfo: Measurements and configuration data of size 512 bytes. > + * > + * More details can be found in TDX v1.0 Module specification, sec > + * titled "TDREPORT_STRUCT". > + */ > +struct tdreport { > + struct reportmac reportmac; > + __u8 tee_tcb_info[239]; > + __u8 reserved[17]; > + struct td_info tdinfo; > +}; > + > +static void print_array_hex(const char *title, const char *prefix_str, > + const void *buf, int len) > +{ > + int i, j, line_len, rowsize = HEX_DUMP_SIZE; > + const __u8 *ptr = buf; > + > + printf("\t\t%s", title); > + > + for (j = 0; j < len; j += rowsize) { > + line_len = rowsize < (len - j) ? rowsize : (len - j); > + printf("%s%.8x:", prefix_str, j); > + for (i = 0; i < line_len; i++) > + printf(" %.2x", ptr[j + i]); > + printf("\n"); > + } > + > + printf("\n"); > +} > + > +TEST(verify_report) > +{ > + struct tdx_report_req req; > + struct tdreport *tdreport; > + int devfd, i; > + > + devfd = open(TDX_GUEST_DEVNAME, O_RDWR | O_SYNC); > + ASSERT_LT(0, devfd); > + > + /* Generate sample report data */ > + for (i = 0; i < TDX_REPORTDATA_LEN; i++) > + req.reportdata[i] = i; > + > + /* Get TDREPORT */ > + ASSERT_EQ(0, ioctl(devfd, TDX_CMD_GET_REPORT, &req)); > + > + if (DEBUG) { > + print_array_hex("\n\t\tTDX report data\n", "", > + req.reportdata, sizeof(req.reportdata)); > + > + print_array_hex("\n\t\tTDX tdreport data\n", "", > + req.tdreport, sizeof(req.tdreport)); > + } > + > + /* Make sure TDREPORT data includes the REPORTDATA passed */ > + tdreport = (struct tdreport *)req.tdreport; > + ASSERT_EQ(0, memcmp(&tdreport->reportmac.reportdata[0], > + req.reportdata, sizeof(req.reportdata))); > + > + ASSERT_EQ(0, close(devfd)); > +} > + > +TEST_HARNESS_MAIN > -- > 2.34.1 > > Acked-by: Wander Lairson Costa <wander@xxxxxxxxxx>
