From: Erdem Aktas erdemaktas@google.com
Adding a test to verify TDX lifecycle by creating a TD and running a dummy TDG.VP.VMCALL <Instruction.IO> inside it.
Co-developed-by: Sagi Shahar sagis@google.com Signed-off-by: Sagi Shahar sagis@google.com Co-developed-by: Ackerley Tng ackerleytng@google.com Signed-off-by: Ackerley Tng ackerleytng@google.com Co-developed-by: Reinette Chatre reinette.chatre@intel.com Signed-off-by: Reinette Chatre reinette.chatre@intel.com Signed-off-by: Erdem Aktas erdemaktas@google.com Signed-off-by: Sagi Shahar sagis@google.com --- tools/testing/selftests/kvm/Makefile.kvm | 4 + .../selftests/kvm/include/x86/tdx/tdcall.h | 32 +++++++ .../selftests/kvm/include/x86/tdx/tdx.h | 12 +++ .../selftests/kvm/include/x86/tdx/test_util.h | 41 ++++++++ .../selftests/kvm/lib/x86/tdx/tdcall.S | 95 +++++++++++++++++++ tools/testing/selftests/kvm/lib/x86/tdx/tdx.c | 27 ++++++ .../selftests/kvm/lib/x86/tdx/test_util.c | 61 ++++++++++++ tools/testing/selftests/kvm/x86/tdx_vm_test.c | 47 +++++++++ 8 files changed, 319 insertions(+) create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/tdcall.h create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/tdx.h create mode 100644 tools/testing/selftests/kvm/include/x86/tdx/test_util.h create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdcall.S create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/tdx.c create mode 100644 tools/testing/selftests/kvm/lib/x86/tdx/test_util.c create mode 100644 tools/testing/selftests/kvm/x86/tdx_vm_test.c
diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index b429c92e07d8..4a147d498bd2 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -31,6 +31,9 @@ LIBKVM_x86 += lib/x86/ucall.c LIBKVM_x86 += lib/x86/vmx.c LIBKVM_x86 += lib/x86/tdx/tdx_util.c LIBKVM_x86 += lib/x86/tdx/td_boot.S +LIBKVM_x86 += lib/x86/tdx/tdcall.S +LIBKVM_x86 += lib/x86/tdx/tdx.c +LIBKVM_x86 += lib/x86/tdx/test_util.c
LIBKVM_arm64 += lib/arm64/gic.c LIBKVM_arm64 += lib/arm64/gic_v3.c @@ -148,6 +151,7 @@ TEST_GEN_PROGS_x86 += rseq_test TEST_GEN_PROGS_x86 += steal_time TEST_GEN_PROGS_x86 += system_counter_offset_test TEST_GEN_PROGS_x86 += pre_fault_memory_test +TEST_GEN_PROGS_x86 += x86/tdx_vm_test
# Compiled outputs used by test targets TEST_GEN_PROGS_EXTENDED_x86 += x86/nx_huge_pages_test diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdcall.h b/tools/testing/selftests/kvm/include/x86/tdx/tdcall.h new file mode 100644 index 000000000000..a6c966e93486 --- /dev/null +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdcall.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Adapted from arch/x86/include/asm/shared/tdx.h */ + +#ifndef SELFTESTS_TDX_TDCALL_H +#define SELFTESTS_TDX_TDCALL_H + +#include <linux/bits.h> +#include <linux/types.h> + +#define TDX_HCALL_HAS_OUTPUT BIT(0) + +#define TDX_HYPERCALL_STANDARD 0 + +/* + * Used in __tdx_hypercall() to pass down and get back registers' values of + * the TDCALL instruction when requesting services from the VMM. + * + * This is a software only structure and not part of the TDX module/VMM ABI. + */ +struct tdx_hypercall_args { + u64 r10; + u64 r11; + u64 r12; + u64 r13; + u64 r14; + u64 r15; +}; + +/* Used to request services from the VMM */ +u64 __tdx_hypercall(struct tdx_hypercall_args *args, unsigned long flags); + +#endif // SELFTESTS_TDX_TDCALL_H diff --git a/tools/testing/selftests/kvm/include/x86/tdx/tdx.h b/tools/testing/selftests/kvm/include/x86/tdx/tdx.h new file mode 100644 index 000000000000..a7161efe4ee2 --- /dev/null +++ b/tools/testing/selftests/kvm/include/x86/tdx/tdx.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef SELFTEST_TDX_TDX_H +#define SELFTEST_TDX_TDX_H + +#include <stdint.h> + +#define TDG_VP_VMCALL_INSTRUCTION_IO 30 + +uint64_t tdg_vp_vmcall_instruction_io(uint64_t port, uint64_t size, + uint64_t write, uint64_t *data); + +#endif // SELFTEST_TDX_TDX_H diff --git a/tools/testing/selftests/kvm/include/x86/tdx/test_util.h b/tools/testing/selftests/kvm/include/x86/tdx/test_util.h new file mode 100644 index 000000000000..07d63bf1ffe1 --- /dev/null +++ b/tools/testing/selftests/kvm/include/x86/tdx/test_util.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef SELFTEST_TDX_TEST_UTIL_H +#define SELFTEST_TDX_TEST_UTIL_H + +#include <stdbool.h> + +#include "tdcall.h" + +#define TDX_TEST_SUCCESS_PORT 0x30 +#define TDX_TEST_SUCCESS_SIZE 4 + +/* Port I/O direction */ +#define PORT_READ 0 +#define PORT_WRITE 1 + +/* + * Run a test in a new process. + * + * There might be multiple tests running and if one test fails, it will + * prevent the subsequent tests to run due to how tests are failing with + * TEST_ASSERT function. run_in_new_process() will run a test in a new process + * context and wait for it to finish or fail to prevent TEST_ASSERT to kill the + * main testing process. + */ +int run_in_new_process(void (*func)(void)); + +/* + * Verify that the TDX is supported by KVM. + */ +bool is_tdx_enabled(void); + +/* + * Report test success to userspace. + * + * Use tdx_test_assert_success() to assert that this function was called in the + * guest. + */ +void tdx_test_success(void); +void tdx_test_assert_success(struct kvm_vcpu *vcpu); + +#endif // SELFTEST_TDX_TEST_UTIL_H diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdcall.S b/tools/testing/selftests/kvm/lib/x86/tdx/tdcall.S new file mode 100644 index 000000000000..b10769d1d557 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdcall.S @@ -0,0 +1,95 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Adapted from arch/x86/coco/tdx/tdcall.S */ + +/* + * TDCALL is supported in Binutils >= 2.36, add it for older version. + */ +#define tdcall .byte 0x66,0x0f,0x01,0xcc + +#define TDX_HYPERCALL_r10 0 /* offsetof(struct tdx_hypercall_args, r10) */ +#define TDX_HYPERCALL_r11 8 /* offsetof(struct tdx_hypercall_args, r11) */ +#define TDX_HYPERCALL_r12 16 /* offsetof(struct tdx_hypercall_args, r12) */ +#define TDX_HYPERCALL_r13 24 /* offsetof(struct tdx_hypercall_args, r13) */ +#define TDX_HYPERCALL_r14 32 /* offsetof(struct tdx_hypercall_args, r14) */ +#define TDX_HYPERCALL_r15 40 /* offsetof(struct tdx_hypercall_args, r15) */ + +/* + * Bitmasks of exposed registers (with VMM). + */ +#define TDX_R10 0x400 +#define TDX_R11 0x800 +#define TDX_R12 0x1000 +#define TDX_R13 0x2000 +#define TDX_R14 0x4000 +#define TDX_R15 0x8000 + +#define TDX_HCALL_HAS_OUTPUT 0x1 + +/* + * These registers are clobbered to hold arguments for each + * TDVMCALL. They are safe to expose to the VMM. + * Each bit in this mask represents a register ID. Bit field + * details can be found in TDX GHCI specification, section + * titled "TDCALL [TDG.VP.VMCALL] leaf". + */ +#define TDVMCALL_EXPOSE_REGS_MASK ( TDX_R10 | TDX_R11 | \ + TDX_R12 | TDX_R13 | \ + TDX_R14 | TDX_R15 ) + +.code64 +.section .text + +.globl __tdx_hypercall +.type __tdx_hypercall, @function +__tdx_hypercall: + /* Set up stack frame */ + push %rbp + movq %rsp, %rbp + + /* Save callee-saved GPRs as mandated by the x86_64 ABI */ + push %r15 + push %r14 + push %r13 + push %r12 + + /* Mangle function call ABI into TDCALL ABI: */ + /* Set TDCALL leaf ID (TDVMCALL (0)) in RAX */ + xor %eax, %eax + + /* Copy hypercall registers from arg struct: */ + movq TDX_HYPERCALL_r10(%rdi), %r10 + movq TDX_HYPERCALL_r11(%rdi), %r11 + movq TDX_HYPERCALL_r12(%rdi), %r12 + movq TDX_HYPERCALL_r13(%rdi), %r13 + movq TDX_HYPERCALL_r14(%rdi), %r14 + movq TDX_HYPERCALL_r15(%rdi), %r15 + + movl $TDVMCALL_EXPOSE_REGS_MASK, %ecx + + tdcall + + /* TDVMCALL leaf return code is in R10 */ + movq %r10, %rax + + /* Copy hypercall result registers to arg struct if needed */ + testq $TDX_HCALL_HAS_OUTPUT, %rsi + jz .Lout + + movq %r10, TDX_HYPERCALL_r10(%rdi) + movq %r11, TDX_HYPERCALL_r11(%rdi) + movq %r12, TDX_HYPERCALL_r12(%rdi) + movq %r13, TDX_HYPERCALL_r13(%rdi) + movq %r14, TDX_HYPERCALL_r14(%rdi) + movq %r15, TDX_HYPERCALL_r15(%rdi) +.Lout: + /* Restore callee-saved GPRs as mandated by the x86_64 ABI */ + pop %r12 + pop %r13 + pop %r14 + pop %r15 + + pop %rbp + ret + +/* Disable executable stack */ +.section .note.GNU-stack,"",%progbits diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/tdx.c b/tools/testing/selftests/kvm/lib/x86/tdx/tdx.c new file mode 100644 index 000000000000..f417ee75bee2 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86/tdx/tdx.c @@ -0,0 +1,27 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include "tdx/tdcall.h" +#include "tdx/tdx.h" + +uint64_t tdg_vp_vmcall_instruction_io(uint64_t port, uint64_t size, + uint64_t write, uint64_t *data) +{ + struct tdx_hypercall_args args = { + .r10 = TDX_HYPERCALL_STANDARD, + .r11 = TDG_VP_VMCALL_INSTRUCTION_IO, + .r12 = size, + .r13 = write, + .r14 = port, + }; + uint64_t ret; + + if (write) + args.r15 = *data; + + ret = __tdx_hypercall(&args, write ? 0 : TDX_HCALL_HAS_OUTPUT); + + if (!write) + *data = args.r11; + + return ret; +} diff --git a/tools/testing/selftests/kvm/lib/x86/tdx/test_util.c b/tools/testing/selftests/kvm/lib/x86/tdx/test_util.c new file mode 100644 index 000000000000..7355b213c344 --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86/tdx/test_util.c @@ -0,0 +1,61 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <stdbool.h> +#include <stdint.h> +#include <stdlib.h> +#include <sys/wait.h> +#include <unistd.h> + +#include "kvm_util.h" +#include "tdx/tdx.h" +#include "tdx/test_util.h" + +int run_in_new_process(void (*func)(void)) +{ + int wstatus; + pid_t ret; + + if (fork() == 0) { + func(); + exit(0); + } + ret = wait(&wstatus); + if (ret == -1) + return -1; + + if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus)) + return -1; + else if (WIFSIGNALED(wstatus)) + return -1; + + return 0; +} + +bool is_tdx_enabled(void) +{ + return !!(kvm_check_cap(KVM_CAP_VM_TYPES) & BIT(KVM_X86_TDX_VM)); +} + +void tdx_test_success(void) +{ + uint64_t code = 0; + + tdg_vp_vmcall_instruction_io(TDX_TEST_SUCCESS_PORT, TDX_TEST_SUCCESS_SIZE, + PORT_WRITE, &code); +} + +/* + * Assert that tdx_test_success() was called in the guest. + */ +void tdx_test_assert_success(struct kvm_vcpu *vcpu) +{ + TEST_ASSERT((vcpu->run->exit_reason == KVM_EXIT_IO) && + (vcpu->run->io.port == TDX_TEST_SUCCESS_PORT) && + (vcpu->run->io.size == TDX_TEST_SUCCESS_SIZE) && + (vcpu->run->io.direction == PORT_WRITE), + "Unexpected exit values while waiting for test completion: %u (%s) %d %d %d\n", + vcpu->run->exit_reason, + exit_reason_str(vcpu->run->exit_reason), + vcpu->run->io.port, vcpu->run->io.size, + vcpu->run->io.direction); +} diff --git a/tools/testing/selftests/kvm/x86/tdx_vm_test.c b/tools/testing/selftests/kvm/x86/tdx_vm_test.c new file mode 100644 index 000000000000..fdb7c40065a6 --- /dev/null +++ b/tools/testing/selftests/kvm/x86/tdx_vm_test.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <signal.h> + +#include "kvm_util.h" +#include "tdx/tdx_util.h" +#include "tdx/test_util.h" +#include "test_util.h" + +static void guest_code_lifecycle(void) +{ + tdx_test_success(); +} + +static void verify_td_lifecycle(void) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + + vm = td_create(); + td_initialize(vm, VM_MEM_SRC_ANONYMOUS, 0); + vcpu = td_vcpu_add(vm, 0, guest_code_lifecycle); + td_finalize(vm); + + printf("Verifying TD lifecycle:\n"); + + vcpu_run(vcpu); + tdx_test_assert_success(vcpu); + + kvm_vm_free(vm); + printf("\t ... PASSED\n"); +} + +int main(int argc, char **argv) +{ + ksft_print_header(); + + if (!is_tdx_enabled()) + ksft_exit_skip("TDX is not supported by the KVM. Exiting.\n"); + + ksft_set_plan(1); + ksft_test_result(!run_in_new_process(&verify_td_lifecycle), + "verify_td_lifecycle\n"); + + ksft_finished(); + return 0; +}