From: Ryan Afranji afranji@google.com
The test checks that host can only read fixed values when trying to access the guest's private memory.
Signed-off-by: Ryan Afranji afranji@google.com Signed-off-by: Sagi Shahar sagis@google.com --- tools/testing/selftests/kvm/x86/tdx_vm_test.c | 83 ++++++++++++++++++- 1 file changed, 82 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kvm/x86/tdx_vm_test.c b/tools/testing/selftests/kvm/x86/tdx_vm_test.c index 2f75f12d2a44..b6ef0348746c 100644 --- a/tools/testing/selftests/kvm/x86/tdx_vm_test.c +++ b/tools/testing/selftests/kvm/x86/tdx_vm_test.c @@ -959,6 +959,85 @@ void verify_td_cpuid_tdcall(void) printf("\t ... PASSED\n"); }
+/* + * Shared variables between guest and host for host reading private mem test + */ +static uint64_t tdx_test_host_read_private_mem_addr; +#define TDX_HOST_READ_PRIVATE_MEM_PORT_TEST 0x53 + +void guest_host_read_priv_mem(void) +{ + uint64_t placeholder = 0; + uint64_t ret; + + /* Set value */ + *((uint32_t *)tdx_test_host_read_private_mem_addr) = 0xABCD; + + /* Exit so host can read value */ + ret = tdg_vp_vmcall_instruction_io(TDX_HOST_READ_PRIVATE_MEM_PORT_TEST, + 4, PORT_WRITE, &placeholder); + tdx_assert_error(ret); + + /* Update guest_var's value and have host reread it. */ + *((uint32_t *)tdx_test_host_read_private_mem_addr) = 0xFEDC; + + tdx_test_success(); +} + +void verify_host_reading_private_mem(void) +{ + uint64_t second_host_read; + uint64_t first_host_read; + struct kvm_vcpu *vcpu; + vm_vaddr_t test_page; + uint64_t *host_virt; + struct kvm_vm *vm; + + vm = td_create(); + td_initialize(vm, VM_MEM_SRC_ANONYMOUS, 0); + vcpu = td_vcpu_add(vm, 0, guest_host_read_priv_mem); + + test_page = vm_vaddr_alloc_page(vm); + TEST_ASSERT(test_page < BIT_ULL(32), + "Test address should fit in 32 bits so it can be sent to the guest"); + + host_virt = addr_gva2hva(vm, test_page); + TEST_ASSERT(host_virt, + "Guest address not found in guest memory regions\n"); + + tdx_test_host_read_private_mem_addr = test_page; + sync_global_to_guest(vm, tdx_test_host_read_private_mem_addr); + + td_finalize(vm); + + printf("Verifying host's behavior when reading TD private memory:\n"); + + tdx_run(vcpu); + tdx_test_assert_io(vcpu, TDX_HOST_READ_PRIVATE_MEM_PORT_TEST, + 4, PORT_WRITE); + printf("\t ... Guest's variable contains 0xABCD\n"); + + /* Host reads guest's variable. */ + first_host_read = *host_virt; + printf("\t ... Host's read attempt value: %lu\n", first_host_read); + + /* Guest updates variable and host rereads it. */ + tdx_run(vcpu); + printf("\t ... Guest's variable updated to 0xFEDC\n"); + + second_host_read = *host_virt; + printf("\t ... Host's second read attempt value: %lu\n", + second_host_read); + + TEST_ASSERT(first_host_read == second_host_read, + "Host did not read a fixed pattern\n"); + + printf("\t ... Fixed pattern was returned to the host\n"); + + kvm_vm_free(vm); + printf("\t ... PASSED\n"); +} + int main(int argc, char **argv) { ksft_print_header(); @@ -966,7 +1045,7 @@ int main(int argc, char **argv) if (!is_tdx_enabled()) ksft_exit_skip("TDX is not supported by the KVM. Exiting.\n");
- ksft_set_plan(13); + ksft_set_plan(14); ksft_test_result(!run_in_new_process(&verify_td_lifecycle), "verify_td_lifecycle\n"); ksft_test_result(!run_in_new_process(&verify_report_fatal_error), @@ -993,6 +1072,8 @@ int main(int argc, char **argv) "verify_mmio_writes\n"); ksft_test_result(!run_in_new_process(&verify_td_cpuid_tdcall), "verify_td_cpuid_tdcall\n"); + ksft_test_result(!run_in_new_process(&verify_host_reading_private_mem), + "verify_host_reading_private_mem\n");
ksft_finished(); return 0;