[RFC PATCH v3 31/31] KVM: selftests: TDX: Add TDX UPM selftests for implicit conversion

Ackerley Tng
2023-01-21T00:30:10Z

This tests the use of restricted memory without explicit MapGPA calls.

Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
.../selftests/kvm/x86_64/tdx_upm_test.c | 88 ++++++++++++++++---
1 file changed, 78 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/tdx_upm_test.c b/tools/testing/selftests/kvm/x86_64/tdx_upm_test.c
index 13914aebd7da7..56ba3d4fb15a5 100644
--- a/tools/testing/selftests/kvm/x86_64/tdx_upm_test.c
+++ b/tools/testing/selftests/kvm/x86_64/tdx_upm_test.c
@@ -149,11 +149,18 @@ enum {
* 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)
+ struct kvm_vcpu *vcpu, bool handle_conversions)
{
for (;;) {
vcpu_run(vcpu);
- if (
+ if (handle_conversions &&
+ vcpu->run->exit_reason == KVM_EXIT_MEMORY_FAULT) {
+ handle_memory_conversion(
+ vm, vcpu->run->memory.gpa,
+ vcpu->run->memory.size,
+ vcpu->run->memory.flags == KVM_MEMORY_EXIT_FLAG_PRIVATE);
+ continue;
+ } else 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(
@@ -233,8 +240,53 @@ static void guest_upm_explicit(void)
tdx_test_success();
}

+static void guest_upm_implicit(void)
+{
+ 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));
+
+ /* Use focus area as shared */
+ fill_focus_area(test_area_gva_shared, PATTERN_GUEST_FOCUS);
+
+ /* General areas should not be affected */
+ TDX_UPM_TEST_ASSERT(
+ check_general_areas(test_area_gva_private, PATTERN_GUEST_GENERAL));
+
+ 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));
+
+ /* Use focus area as private */
+ fill_focus_area(test_area_gva_private, PATTERN_GUEST_FOCUS);
+
+ /* General areas should be unaffected by remapping */
+ TDX_UPM_TEST_ASSERT(
+ check_general_areas(test_area_gva_private, PATTERN_GUEST_GENERAL));
+
+ 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)
+ struct tdx_upm_test_area *test_area_base_hva,
+ bool implicit)
{
vcpu_run(vcpu);
TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
@@ -253,7 +305,7 @@ static void run_selftest(struct kvm_vm *vm, struct kvm_vcpu *vcpu,
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);
+ vcpu_run_and_manage_memory_conversions(vm, vcpu, implicit);
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);
@@ -270,7 +322,7 @@ static void run_selftest(struct kvm_vm *vm, struct kvm_vcpu *vcpu,
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);
+ vcpu_run_and_manage_memory_conversions(vm, vcpu, implicit);
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);
@@ -319,18 +371,20 @@ static void guest_ve_handler(struct ex_regs *regs)
TDX_UPM_TEST_ASSERT(!ret);
}

-static void verify_upm_test(void)
+static void verify_upm_test(bool implicit)
{
struct kvm_vm *vm;
struct kvm_vcpu *vcpu;

+ void *guest_code;
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);
+ guest_code = implicit ? guest_upm_implicit : guest_upm_explicit;
+ vcpu = td_vcpu_add(vm, 0, guest_code);

vm_install_exception_handler(vm, VE_VECTOR, guest_ve_handler);

@@ -370,13 +424,26 @@ static void verify_upm_test(void)

td_finalize(vm);

- printf("Verifying UPM functionality: explicit MapGPA\n");
+ if (implicit)
+ printf("Verifying UPM functionality: implicit conversion\n");
+ else
+ printf("Verifying UPM functionality: explicit MapGPA\n");

- run_selftest(vm, vcpu, test_area_base_hva);
+ run_selftest(vm, vcpu, test_area_base_hva, implicit);

kvm_vm_free(vm);
}

+void verify_upm_test_explicit(void)
+{
+ verify_upm_test(false);
+}
+
+void verify_upm_test_implicit(void)
+{
+ verify_upm_test(true);
+}
+
int main(int argc, char **argv)
{
/* Disable stdout buffering */
@@ -388,5 +455,6 @@ int main(int argc, char **argv)
return 0;
}

- run_in_new_process(&verify_upm_test);
+ run_in_new_process(&verify_upm_test_explicit);
+ run_in_new_process(&verify_upm_test_implicit);
}
--
2.39.0.246.g2a6d74b583-goog