> +void guest_shared_mem(void)
> +{
> + uint32_t *test_mem_shared_gva =
> + (uint32_t *)TDX_SHARED_MEM_TEST_SHARED_GVA;
> +
> + uint64_t placeholder;
> + uint64_t ret;
> +
> + /* Map gpa as shared */
> + ret = tdg_vp_vmcall_map_gpa(test_mem_shared_gpa, PAGE_SIZE,
> + &placeholder);
> + if (ret)
> + tdx_test_fatal_with_data(ret, __LINE__);
> +
> + *test_mem_shared_gva = TDX_SHARED_MEM_TEST_GUEST_WRITE_VALUE;
> +
> + /* Exit so host can read shared value */
> + ret = tdg_vp_vmcall_instruction_io(TDX_SHARED_MEM_TEST_INFO_PORT, 4,
> + TDG_VP_VMCALL_INSTRUCTION_IO_WRITE,
> + &placeholder);
> + if (ret)
> + tdx_test_fatal_with_data(ret, __LINE__);
> +
> + /* Read value written by host and send it back out for verification */
> + ret = tdg_vp_vmcall_instruction_io(TDX_SHARED_MEM_TEST_INFO_PORT, 4,
> + TDG_VP_VMCALL_INSTRUCTION_IO_WRITE,
> + (uint64_t *)test_mem_shared_gva);
> + if (ret)
> + tdx_test_fatal_with_data(ret, __LINE__);
> +}
> +
> +int verify_shared_mem(void)
> +{
> + struct kvm_vm *vm;
> + struct kvm_vcpu *vcpu;
> +
> + vm_vaddr_t test_mem_private_gva;
> + uint32_t *test_mem_hva;
> +
> + vm = td_create();
> + td_initialize(vm, VM_MEM_SRC_ANONYMOUS, 0);
> + vcpu = td_vcpu_add(vm, 0, guest_shared_mem);
> +
> + /*
> + * 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_mem_private_gva = vm_vaddr_alloc(vm, vm->page_size,
> + TDX_SHARED_MEM_TEST_PRIVATE_GVA);
> + TEST_ASSERT_EQ(test_mem_private_gva, TDX_SHARED_MEM_TEST_PRIVATE_GVA);
> +
> + test_mem_hva = addr_gva2hva(vm, test_mem_private_gva);
> + TEST_ASSERT(test_mem_hva != NULL,
> + "Guest address not found in guest memory regions\n");
> +
> + test_mem_private_gpa = addr_gva2gpa(vm, test_mem_private_gva);
> + virt_pg_map_shared(vm, TDX_SHARED_MEM_TEST_SHARED_GVA,
> + test_mem_private_gpa);
> +
> + test_mem_shared_gpa = test_mem_private_gpa | BIT_ULL(vm->pa_bits - 1);
> + sync_global_to_guest(vm, test_mem_private_gpa);
> + sync_global_to_guest(vm, test_mem_shared_gpa);
> +
> + td_finalize(vm);
> +
> + printf("Verifying shared memory accesses for TDX\n");
> +
> + /* Begin guest execution; guest writes to shared memory. */
> + printf("\t ... Starting guest execution\n");
> +
> + /* Handle map gpa as shared */
> + td_vcpu_run(vcpu);
> + TDX_TEST_CHECK_GUEST_FAILURE(vcpu);
The first VMExit should be caused by tdvmcall map gpa, so it's
impossible to be guest failure.
Move this line TDX_TEST_CHECK_GUEST_FAILURE(vcpu) to after the next td_vcpu_run()
is better.
> +
> + td_vcpu_run(vcpu);
> + TDX_TEST_ASSERT_IO(vcpu, TDX_SHARED_MEM_TEST_INFO_PORT, 4,
> + TDG_VP_VMCALL_INSTRUCTION_IO_WRITE);
> + TEST_ASSERT_EQ(*test_mem_hva, TDX_SHARED_MEM_TEST_GUEST_WRITE_VALUE);
> +
> + *test_mem_hva = TDX_SHARED_MEM_TEST_HOST_WRITE_VALUE;
> + td_vcpu_run(vcpu);
> + TDX_TEST_ASSERT_IO(vcpu, TDX_SHARED_MEM_TEST_INFO_PORT, 4,
> + TDG_VP_VMCALL_INSTRUCTION_IO_WRITE);
> + TEST_ASSERT_EQ(
> + *(uint32_t *)((void *)vcpu->run + vcpu->run->io.data_offset),
> + TDX_SHARED_MEM_TEST_HOST_WRITE_VALUE);
> +
> + printf("\t ... PASSED\n");
> +
> + kvm_vm_free(vm);
> +
> + return 0;
> +}
