On 12/13/2023 4:46 AM, Sagi Shahar wrote:
The test verifies that the guest runs TDVMCALL<INSTRUCTION.HLT> and the guest vCPU enters to the halted state.
Signed-off-by: Erdem Aktas erdemaktas@google.com Signed-off-by: Sagi Shahar sagis@google.com Signed-off-by: Ackerley Tng ackerleytng@google.com Signed-off-by: Ryan Afranji afranji@google.com
.../selftests/kvm/include/x86_64/tdx/tdx.h | 2 + .../selftests/kvm/lib/x86_64/tdx/tdx.c | 10 +++ .../selftests/kvm/x86_64/tdx_vm_tests.c | 78 +++++++++++++++++++ 3 files changed, 90 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h index 85ba6aab79a7..b18e39d20498 100644 --- a/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h +++ b/tools/testing/selftests/kvm/include/x86_64/tdx/tdx.h @@ -8,6 +8,7 @@ #define TDG_VP_VMCALL_GET_TD_VM_CALL_INFO 0x10000 #define TDG_VP_VMCALL_REPORT_FATAL_ERROR 0x10003 +#define TDG_VP_VMCALL_INSTRUCTION_HLT 12 #define TDG_VP_VMCALL_INSTRUCTION_IO 30 #define TDG_VP_VMCALL_INSTRUCTION_RDMSR 31 #define TDG_VP_VMCALL_INSTRUCTION_WRMSR 32 @@ -20,5 +21,6 @@ uint64_t tdg_vp_vmcall_get_td_vmcall_info(uint64_t *r11, uint64_t *r12, uint64_t *r13, uint64_t *r14); uint64_t tdg_vp_vmcall_instruction_rdmsr(uint64_t index, uint64_t *ret_value); uint64_t tdg_vp_vmcall_instruction_wrmsr(uint64_t index, uint64_t value); +uint64_t tdg_vp_vmcall_instruction_hlt(uint64_t interrupt_blocked_flag); #endif // SELFTEST_TDX_TDX_H diff --git a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c index 88ea6f2a6469..9485bafedc38 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c +++ b/tools/testing/selftests/kvm/lib/x86_64/tdx/tdx.c @@ -114,3 +114,13 @@ uint64_t tdg_vp_vmcall_instruction_wrmsr(uint64_t index, uint64_t value) return __tdx_hypercall(&args, 0); }
+uint64_t tdg_vp_vmcall_instruction_hlt(uint64_t interrupt_blocked_flag) +{
- struct tdx_hypercall_args args = {
.r11 = TDG_VP_VMCALL_INSTRUCTION_HLT,.r12 = interrupt_blocked_flag,- };
- return __tdx_hypercall(&args, 0);
+} 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 5db3701cc6d9..5fae4c6e5f95 100644 --- a/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c +++ b/tools/testing/selftests/kvm/x86_64/tdx_vm_tests.c @@ -721,6 +721,83 @@ void verify_guest_msr_writes(void) printf("\t ... PASSED\n"); } +/*
- Verifies HLT functionality.
- */
+void guest_hlt(void) +{
- uint64_t ret;
- uint64_t interrupt_blocked_flag;
- interrupt_blocked_flag = 0;
- ret = tdg_vp_vmcall_instruction_hlt(interrupt_blocked_flag);
- if (ret)
tdx_test_fatal(ret);- tdx_test_success();
+}
+void _verify_guest_hlt(int signum);
+void wake_me(int interval) +{
- struct sigaction action;
- action.sa_handler = _verify_guest_hlt;
- sigemptyset(&action.sa_mask);
- action.sa_flags = 0;
- TEST_ASSERT(sigaction(SIGALRM, &action, NULL) == 0,
"Could not set the alarm handler!");- alarm(interval);
+}
+void _verify_guest_hlt(int signum) +{
- struct kvm_vm *vm;
- static struct kvm_vcpu *vcpu;
- /*
* This function will also be called by SIGALRM handler to check the* vCPU MP State. If vm has been initialized, then we are in the signal* handler. Check the MP state and let the guest run again.*/- if (vcpu != NULL) {
What if the following case if there is a bug in KVM so that:
In guest, execution of tdg_vp_vmcall_instruction_hlt() return 0, but the vcpu is not actually halted. Then guest will call tdx_test_success().
And the first call of _verify_guest_hlt() will call kvm_vm_free(vm) to free the vm, which also frees the vcpu, and 1 second later, in this path vcpu will be accessed after free.
struct kvm_mp_state mp_state;vcpu_mp_state_get(vcpu, &mp_state);TEST_ASSERT_EQ(mp_state.mp_state, KVM_MP_STATE_HALTED);/* Let the guest to run and finish the test.*/mp_state.mp_state = KVM_MP_STATE_RUNNABLE;vcpu_mp_state_set(vcpu, &mp_state);return;- }
- vm = td_create();
- td_initialize(vm, VM_MEM_SRC_ANONYMOUS, 0);
- vcpu = td_vcpu_add(vm, 0, guest_hlt);
- td_finalize(vm);
- printf("Verifying HLT:\n");
- printf("\t ... Running guest\n");
- /* Wait 1 second for guest to execute HLT */
- wake_me(1);
- td_vcpu_run(vcpu);
- TDX_TEST_ASSERT_SUCCESS(vcpu);
- kvm_vm_free(vm);
- printf("\t ... PASSED\n");
+}
+void verify_guest_hlt(void) +{
- _verify_guest_hlt(0);
+} int main(int argc, char **argv) { @@ -740,6 +817,7 @@ int main(int argc, char **argv) run_in_new_process(&verify_guest_reads); run_in_new_process(&verify_guest_msr_writes); run_in_new_process(&verify_guest_msr_reads);
- run_in_new_process(&verify_guest_hlt);
return 0; }