This tests the use of restricted memory with explicit MapGPA calls.
Signed-off-by: Ackerley Tng ackerleytng@google.com --- tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/x86_64/tdx_upm_test.c | 392 ++++++++++++++++++ 3 files changed, 394 insertions(+) create mode 100644 tools/testing/selftests/kvm/x86_64/tdx_upm_test.c
diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore index e1663b0f809b4..c1def2271f4cd 100644 --- a/tools/testing/selftests/kvm/.gitignore +++ b/tools/testing/selftests/kvm/.gitignore @@ -67,6 +67,7 @@ /x86_64/triple_fault_event_test /x86_64/tdx_vm_tests /x86_64/tdx_shared_mem_test +/x86_64/tdx_upm_test /access_tracking_perf_test /demand_paging_test /dirty_log_test diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 27e9148212fa5..2b1434368a0f2 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -153,6 +153,7 @@ TEST_GEN_PROGS_x86_64 += kvm_binary_stats_test TEST_GEN_PROGS_x86_64 += system_counter_offset_test TEST_GEN_PROGS_x86_64 += x86_64/tdx_vm_tests TEST_GEN_PROGS_x86_64 += x86_64/tdx_shared_mem_test +TEST_GEN_PROGS_x86_64 += x86_64/tdx_upm_test
# Compiled outputs used by test targets TEST_GEN_PROGS_EXTENDED_x86_64 += x86_64/nx_huge_pages_test diff --git a/tools/testing/selftests/kvm/x86_64/tdx_upm_test.c b/tools/testing/selftests/kvm/x86_64/tdx_upm_test.c new file mode 100644 index 0000000000000..13914aebd7da7 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/tdx_upm_test.c @@ -0,0 +1,392 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <asm/kvm.h> +#include <asm/vmx.h> +#include <linux/kvm.h> +#include <stdbool.h> +#include <stdint.h> + +#include "kvm_util_base.h" +#include "processor.h" +#include "tdx/tdcall.h" +#include "tdx/tdx.h" +#include "tdx/tdx_util.h" +#include "tdx/test_util.h" +#include "test_util.h" + +/* TDX UPM test patterns */ +#define PATTERN_CONFIDENCE_CHECK (0x11) +#define PATTERN_HOST_FOCUS (0x22) +#define PATTERN_GUEST_GENERAL (0x33) +#define PATTERN_GUEST_FOCUS (0x44) + +/* + * 0x80000000 is arbitrarily selected. The selected address need not be the same + * as TDX_UPM_TEST_AREA_GVA_PRIVATE, but it should not overlap with selftest + * code or boot page. + */ +#define TDX_UPM_TEST_AREA_GPA (0x80000000) +/* Test area GPA is arbitrarily selected */ +#define TDX_UPM_TEST_AREA_GVA_PRIVATE (0x90000000) +/* Select any bit that can be used as a flag */ +#define TDX_UPM_TEST_AREA_GVA_SHARED_BIT (32) +/* + * TDX_UPM_TEST_AREA_GVA_SHARED is used to map the same GPA twice into the + * guest, once as shared and once as private + */ +#define TDX_UPM_TEST_AREA_GVA_SHARED \ + (TDX_UPM_TEST_AREA_GVA_PRIVATE | \ + BIT_ULL(TDX_UPM_TEST_AREA_GVA_SHARED_BIT)) + +/* The test area is 2MB in size */ +#define TDX_UPM_TEST_AREA_SIZE (2 << 20) +/* 0th general area is 1MB in size */ +#define TDX_UPM_GENERAL_AREA_0_SIZE (1 << 20) +/* Focus area is 40KB in size */ +#define TDX_UPM_FOCUS_AREA_SIZE (40 << 10) +/* 1st general area is the rest of the space in the test area */ +#define TDX_UPM_GENERAL_AREA_1_SIZE \ + (TDX_UPM_TEST_AREA_SIZE - TDX_UPM_GENERAL_AREA_0_SIZE - \ + TDX_UPM_FOCUS_AREA_SIZE) + +/* + * The test memory area is set up as two general areas, sandwiching a focus + * area. The general areas act as control areas. After they are filled, they + * are not expected to change throughout the tests. The focus area is memory + * permissions change from private to shared and vice-versa. + * + * The focus area is intentionally small, and sandwiched to test that when the + * focus area's permissions change, the other areas' permissions are not + * affected. + */ +struct __packed tdx_upm_test_area { + uint8_t general_area_0[TDX_UPM_GENERAL_AREA_0_SIZE]; + uint8_t focus_area[TDX_UPM_FOCUS_AREA_SIZE]; + uint8_t general_area_1[TDX_UPM_GENERAL_AREA_1_SIZE]; +}; + +static void fill_test_area(struct tdx_upm_test_area *test_area_base, + uint8_t pattern) +{ + memset(test_area_base, pattern, sizeof(*test_area_base)); +} + +static void fill_focus_area(struct tdx_upm_test_area *test_area_base, + uint8_t pattern) +{ + memset(test_area_base->focus_area, pattern, + sizeof(test_area_base->focus_area)); +} + +static bool check_area(uint8_t *base, uint64_t size, uint8_t expected_pattern) +{ + size_t i; + + for (i = 0; i < size; i++) { + if (base[i] != expected_pattern) + return false; + } + + return true; +} + +static bool check_general_areas(struct tdx_upm_test_area *test_area_base, + uint8_t expected_pattern) +{ + return (check_area(test_area_base->general_area_0, + sizeof(test_area_base->general_area_0), + expected_pattern) && + check_area(test_area_base->general_area_1, + sizeof(test_area_base->general_area_1), + expected_pattern)); +} + +static bool check_focus_area(struct tdx_upm_test_area *test_area_base, + uint8_t expected_pattern) +{ + return check_area(test_area_base->focus_area, + sizeof(test_area_base->focus_area), expected_pattern); +} + +static bool check_test_area(struct tdx_upm_test_area *test_area_base, + uint8_t expected_pattern) +{ + return (check_general_areas(test_area_base, expected_pattern) && + check_focus_area(test_area_base, expected_pattern)); +} + +static bool fill_and_check(struct tdx_upm_test_area *test_area_base, uint8_t pattern) +{ + fill_test_area(test_area_base, pattern); + + return check_test_area(test_area_base, pattern); +} + +#define TDX_UPM_TEST_ASSERT(x) \ + do { \ + if (!(x)) \ + tdx_test_fatal(__LINE__); \ + } while (0) + +/* + * Shared variables between guest and host + */ +static struct tdx_upm_test_area *test_area_gpa_private; +static struct tdx_upm_test_area *test_area_gpa_shared; + +/* + * Test stages for syncing with host + */ +enum { + SYNC_CHECK_READ_PRIVATE_MEMORY_FROM_HOST = 1, + SYNC_CHECK_READ_SHARED_MEMORY_FROM_HOST, + SYNC_CHECK_READ_PRIVATE_MEMORY_FROM_HOST_AGAIN, +}; + +#define TDX_UPM_TEST_ACCEPT_PRINT_PORT 0x87 + +/** + * Does vcpu_run, and also manages memory conversions if requested by the TD. + */ +void vcpu_run_and_manage_memory_conversions(struct kvm_vm *vm, + struct kvm_vcpu *vcpu) +{ + for (;;) { + vcpu_run(vcpu); + if ( + vcpu->run->exit_reason == KVM_EXIT_IO && + vcpu->run->io.port == TDX_UPM_TEST_ACCEPT_PRINT_PORT) { + uint64_t gpa = tdx_test_read_64bit( + vcpu, TDX_UPM_TEST_ACCEPT_PRINT_PORT); + printf("\t ... guest accepting 1 page at GPA: 0x%lx\n", gpa); + continue; + } + + break; + } +} + +static void guest_upm_explicit(void) +{ + uint64_t ret = 0; + uint64_t failed_gpa; + + struct tdx_upm_test_area *test_area_gva_private = + (struct tdx_upm_test_area *)TDX_UPM_TEST_AREA_GVA_PRIVATE; + struct tdx_upm_test_area *test_area_gva_shared = + (struct tdx_upm_test_area *)TDX_UPM_TEST_AREA_GVA_SHARED; + + /* Check: host reading private memory does not modify guest's view */ + fill_test_area(test_area_gva_private, PATTERN_GUEST_GENERAL); + + tdx_test_report_to_user_space(SYNC_CHECK_READ_PRIVATE_MEMORY_FROM_HOST); + + TDX_UPM_TEST_ASSERT( + check_test_area(test_area_gva_private, PATTERN_GUEST_GENERAL)); + + /* Remap focus area as shared */ + ret = tdg_vp_vmcall_map_gpa((uint64_t)test_area_gpa_shared->focus_area, + sizeof(test_area_gpa_shared->focus_area), + &failed_gpa); + TDX_UPM_TEST_ASSERT(!ret); + + /* General areas should be unaffected by remapping */ + TDX_UPM_TEST_ASSERT( + check_general_areas(test_area_gva_private, PATTERN_GUEST_GENERAL)); + + /* + * Use memory contents to confirm that the memory allocated using mmap + * is used as backing memory for shared memory - PATTERN_CONFIDENCE_CHECK + * was written by the VMM at the beginning of this test. + */ + TDX_UPM_TEST_ASSERT( + check_focus_area(test_area_gva_shared, PATTERN_CONFIDENCE_CHECK)); + + /* Guest can use focus area after remapping as shared */ + fill_focus_area(test_area_gva_shared, PATTERN_GUEST_FOCUS); + + tdx_test_report_to_user_space(SYNC_CHECK_READ_SHARED_MEMORY_FROM_HOST); + + /* Check that guest has the same view of shared memory */ + TDX_UPM_TEST_ASSERT( + check_focus_area(test_area_gva_shared, PATTERN_HOST_FOCUS)); + + /* Remap focus area back to private */ + ret = tdg_vp_vmcall_map_gpa((uint64_t)test_area_gpa_private->focus_area, + sizeof(test_area_gpa_private->focus_area), + &failed_gpa); + TDX_UPM_TEST_ASSERT(!ret); + + /* General areas should be unaffected by remapping */ + TDX_UPM_TEST_ASSERT( + check_general_areas(test_area_gva_private, PATTERN_GUEST_GENERAL)); + + /* Focus area should be zeroed after remapping */ + TDX_UPM_TEST_ASSERT(check_focus_area(test_area_gva_private, 0)); + + tdx_test_report_to_user_space(SYNC_CHECK_READ_PRIVATE_MEMORY_FROM_HOST_AGAIN); + + /* Check that guest can use private memory after focus area is remapped as private */ + TDX_UPM_TEST_ASSERT( + fill_and_check(test_area_gva_private, PATTERN_GUEST_GENERAL)); + + tdx_test_success(); +} + +static void run_selftest(struct kvm_vm *vm, struct kvm_vcpu *vcpu, + struct tdx_upm_test_area *test_area_base_hva) +{ + vcpu_run(vcpu); + TDX_TEST_CHECK_GUEST_FAILURE(vcpu); + TDX_TEST_ASSERT_IO(vcpu, TDX_TEST_REPORT_PORT, TDX_TEST_REPORT_SIZE, + TDG_VP_VMCALL_INSTRUCTION_IO_WRITE); + ASSERT_EQ(*(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset), + SYNC_CHECK_READ_PRIVATE_MEMORY_FROM_HOST); + + /* + * Check that host should read PATTERN_CONFIDENCE_CHECK from guest's + * private memory. This confirms that regular memory (userspace_addr in + * struct kvm_userspace_memory_region) is used to back the host's view + * of private memory, since PATTERN_CONFIDENCE_CHECK was written to that + * memory before starting the guest. + */ + TEST_ASSERT(check_test_area(test_area_base_hva, PATTERN_CONFIDENCE_CHECK), + "Host should read PATTERN_CONFIDENCE_CHECK from guest's private memory."); + + vcpu_run_and_manage_memory_conversions(vm, vcpu); + TDX_TEST_CHECK_GUEST_FAILURE(vcpu); + TDX_TEST_ASSERT_IO(vcpu, TDX_TEST_REPORT_PORT, TDX_TEST_REPORT_SIZE, + TDG_VP_VMCALL_INSTRUCTION_IO_WRITE); + ASSERT_EQ(*(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset), + SYNC_CHECK_READ_SHARED_MEMORY_FROM_HOST); + + TEST_ASSERT(check_focus_area(test_area_base_hva, PATTERN_GUEST_FOCUS), + "Host should have the same view of shared memory as guest."); + TEST_ASSERT(check_general_areas(test_area_base_hva, PATTERN_CONFIDENCE_CHECK), + "Host's view of private memory should still be backed by regular memory."); + + /* Check that host can use shared memory */ + fill_focus_area(test_area_base_hva, PATTERN_HOST_FOCUS); + TEST_ASSERT(check_focus_area(test_area_base_hva, PATTERN_HOST_FOCUS), + "Host should be able to use shared memory."); + + vcpu_run_and_manage_memory_conversions(vm, vcpu); + TDX_TEST_CHECK_GUEST_FAILURE(vcpu); + TDX_TEST_ASSERT_IO(vcpu, TDX_TEST_REPORT_PORT, TDX_TEST_REPORT_SIZE, + TDG_VP_VMCALL_INSTRUCTION_IO_WRITE); + ASSERT_EQ(*(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset), + SYNC_CHECK_READ_PRIVATE_MEMORY_FROM_HOST_AGAIN); + + TEST_ASSERT(check_general_areas(test_area_base_hva, PATTERN_CONFIDENCE_CHECK), + "Host's view of private memory should be backed by regular memory."); + TEST_ASSERT(check_focus_area(test_area_base_hva, PATTERN_HOST_FOCUS), + "Host's view of private memory should be backed by regular memory."); + + vcpu_run(vcpu); + TDX_TEST_CHECK_GUEST_FAILURE(vcpu); + TDX_TEST_ASSERT_SUCCESS(vcpu); + + printf("\t ... PASSED\n"); +} + +static bool address_between(uint64_t addr, void *lo, void *hi) +{ + return (uint64_t)lo <= addr && addr < (uint64_t)hi; +} + +static void guest_ve_handler(struct ex_regs *regs) +{ + uint64_t ret; + struct ve_info ve; + + ret = tdg_vp_veinfo_get(&ve); + TDX_UPM_TEST_ASSERT(!ret); + + /* For this test, we will only handle EXIT_REASON_EPT_VIOLATION */ + TDX_UPM_TEST_ASSERT(ve.exit_reason == EXIT_REASON_EPT_VIOLATION); + + /* Validate GPA in fault */ + TDX_UPM_TEST_ASSERT( + address_between(ve.gpa, + test_area_gpa_private->focus_area, + test_area_gpa_private->general_area_1)); + + tdx_test_send_64bit(TDX_UPM_TEST_ACCEPT_PRINT_PORT, ve.gpa); + +#define MEM_PAGE_ACCEPT_LEVEL_4K 0 +#define MEM_PAGE_ACCEPT_LEVEL_2M 1 + ret = tdg_mem_page_accept(ve.gpa, MEM_PAGE_ACCEPT_LEVEL_4K); + TDX_UPM_TEST_ASSERT(!ret); +} + +static void verify_upm_test(void) +{ + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + + vm_vaddr_t test_area_gva_private; + struct tdx_upm_test_area *test_area_base_hva; + uint64_t test_area_npages; + + vm = td_create(); + td_initialize(vm, VM_MEM_SRC_ANONYMOUS, 0); + vcpu = td_vcpu_add(vm, 0, guest_upm_explicit); + + vm_install_exception_handler(vm, VE_VECTOR, guest_ve_handler); + + /* + * Set up shared memory page for testing by first allocating as private + * and then mapping the same GPA again as shared. This way, the TD does + * not have to remap its page tables at runtime. + */ + test_area_npages = TDX_UPM_TEST_AREA_SIZE / vm->page_size; + vm_userspace_mem_region_add(vm, + VM_MEM_SRC_ANONYMOUS_AND_RESTRICTED_MEMFD, + TDX_UPM_TEST_AREA_GPA, 3, test_area_npages, + 0); + + test_area_gva_private = _vm_vaddr_alloc( + vm, TDX_UPM_TEST_AREA_SIZE, TDX_UPM_TEST_AREA_GVA_PRIVATE, + TDX_UPM_TEST_AREA_GPA, 3, true); + ASSERT_EQ(test_area_gva_private, TDX_UPM_TEST_AREA_GVA_PRIVATE); + + test_area_gpa_private = (struct tdx_upm_test_area *) + addr_gva2gpa(vm, test_area_gva_private); + virt_map_shared(vm, TDX_UPM_TEST_AREA_GVA_SHARED, + (uint64_t)test_area_gpa_private, + test_area_npages); + ASSERT_EQ(addr_gva2gpa(vm, TDX_UPM_TEST_AREA_GVA_SHARED), + (vm_paddr_t)test_area_gpa_private); + + test_area_base_hva = addr_gva2hva(vm, TDX_UPM_TEST_AREA_GVA_PRIVATE); + + TEST_ASSERT(fill_and_check(test_area_base_hva, PATTERN_CONFIDENCE_CHECK), + "Failed to mark memory intended as backing memory for TD shared memory"); + + sync_global_to_guest(vm, test_area_gpa_private); + test_area_gpa_shared = (struct tdx_upm_test_area *) + ((uint64_t)test_area_gpa_private | BIT_ULL(vm->pa_bits - 1)); + sync_global_to_guest(vm, test_area_gpa_shared); + + td_finalize(vm); + + printf("Verifying UPM functionality: explicit MapGPA\n"); + + run_selftest(vm, vcpu, test_area_base_hva); + + kvm_vm_free(vm); +} + +int main(int argc, char **argv) +{ + /* Disable stdout buffering */ + setbuf(stdout, NULL); + + if (!is_tdx_enabled()) { + printf("TDX is not supported by the KVM\n" + "Skipping the TDX tests.\n"); + return 0; + } + + run_in_new_process(&verify_upm_test); +}