The test verifies MMIO writes of various sizes from the guest to the host.
Signed-off-by: Sagi Shahar sagis@google.com --- tools/testing/selftests/kvm/lib/x86_64/tdx.h | 18 ++++ .../selftests/kvm/x86_64/tdx_vm_tests.c | 92 +++++++++++++++++++ 2 files changed, 110 insertions(+)
diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx.h b/tools/testing/selftests/kvm/lib/x86_64/tdx.h index 7045d617dd78..17e3649e5729 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/tdx.h +++ b/tools/testing/selftests/kvm/lib/x86_64/tdx.h @@ -329,6 +329,24 @@ static inline uint64_t tdvmcall_mmio_read(uint64_t address, uint64_t size, uint6 return regs.r10; }
+/* + * Execute MMIO request instruction for write. + */ +static inline uint64_t tdvmcall_mmio_write(uint64_t address, uint64_t size, uint64_t data_in) +{ + struct kvm_regs regs; + + memset(®s, 0, sizeof(regs)); + regs.r11 = TDX_INSTRUCTION_VE_REQUEST_MMIO; + regs.r12 = size; + regs.r13 = TDX_MMIO_WRITE; + regs.r14 = address; + regs.r15 = data_in; + regs.rcx = 0xFC00; + tdcall(®s); + return regs.r10; +} + /* * Reports a 32 bit value from the guest to user space using a TDVM IO call. * Data is reported on port TDX_DATA_REPORT_PORT. diff --git a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c index 963e4feae31a..382119bd444b 100644 --- a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c +++ b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c @@ -1082,6 +1082,97 @@ void verify_mmio_reads(void) printf("\t ... PASSED\n"); }
+TDX_GUEST_FUNCTION(guest_mmio_writes) +{ + uint64_t ret; + + ret = tdvmcall_mmio_write(MMIO_VALID_ADDRESS, 1, 0x12); + if (ret) + tdvmcall_fatal(ret); + + ret = tdvmcall_mmio_write(MMIO_VALID_ADDRESS, 2, 0x1234); + if (ret) + tdvmcall_fatal(ret); + + ret = tdvmcall_mmio_write(MMIO_VALID_ADDRESS, 4, 0x12345678); + if (ret) + tdvmcall_fatal(ret); + + ret = tdvmcall_mmio_write(MMIO_VALID_ADDRESS, 8, 0x1234567890ABCDEF); + if (ret) + tdvmcall_fatal(ret); + + // Write across page boundary. + ret = tdvmcall_mmio_write(PAGE_SIZE - 1, 8, 0); + if (ret) + tdvmcall_fatal(ret); + + tdvmcall_success(); +} + +/* + * Varifies guest MMIO writes. + */ +void verify_mmio_writes(void) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + uint8_t byte_1; + uint16_t byte_2; + uint32_t byte_4; + uint64_t byte_8; + + printf("Verifying TD MMIO writes:\n"); + /* Create a TD VM with no memory.*/ + vm = vm_create_tdx(); + + /* Allocate TD guest memory and initialize the TD.*/ + initialize_td(vm); + + /* Initialize the TD vcpu and copy the test code to the guest memory.*/ + vcpu = vm_vcpu_add_tdx(vm, 0); + + /* Setup and initialize VM memory */ + prepare_source_image(vm, guest_mmio_writes, + TDX_FUNCTION_SIZE(guest_mmio_writes), 0); + finalize_td_memory(vm); + + vcpu_run(vcpu); + CHECK_GUEST_FAILURE(vcpu); + CHECK_MMIO(vcpu, MMIO_VALID_ADDRESS, 1, TDX_MMIO_WRITE); + byte_1 = *(uint8_t *)(vcpu->run->mmio.data); + + vcpu_run(vcpu); + CHECK_GUEST_FAILURE(vcpu); + CHECK_MMIO(vcpu, MMIO_VALID_ADDRESS, 2, TDX_MMIO_WRITE); + byte_2 = *(uint16_t *)(vcpu->run->mmio.data); + + vcpu_run(vcpu); + CHECK_GUEST_FAILURE(vcpu); + CHECK_MMIO(vcpu, MMIO_VALID_ADDRESS, 4, TDX_MMIO_WRITE); + byte_4 = *(uint32_t *)(vcpu->run->mmio.data); + + vcpu_run(vcpu); + CHECK_GUEST_FAILURE(vcpu); + CHECK_MMIO(vcpu, MMIO_VALID_ADDRESS, 8, TDX_MMIO_WRITE); + byte_8 = *(uint64_t *)(vcpu->run->mmio.data); + + ASSERT_EQ(byte_1, 0x12); + ASSERT_EQ(byte_2, 0x1234); + ASSERT_EQ(byte_4, 0x12345678); + ASSERT_EQ(byte_8, 0x1234567890ABCDEF); + + vcpu_run(vcpu); + ASSERT_EQ(vcpu->run->exit_reason, KVM_EXIT_SYSTEM_EVENT); + ASSERT_EQ(vcpu->run->system_event.data[1], TDX_VMCALL_INVALID_OPERAND); + + vcpu_run(vcpu); + CHECK_GUEST_COMPLETION(vcpu); + + kvm_vm_free(vm); + printf("\t ... PASSED\n"); +} + int main(int argc, char **argv) { if (!is_tdx_enabled()) { @@ -1100,6 +1191,7 @@ int main(int argc, char **argv) run_in_new_process(&verify_guest_msr_writes); run_in_new_process(&verify_guest_hlt); run_in_new_process(&verify_mmio_reads); + run_in_new_process(&verify_mmio_writes);
return 0; }