KVM: selftests: Add ex_str() to print human friendly name of exception vectors

Steal exception_mnemonic() from KVM-Unit-Tests as ex_str() (to keep line
lengths reasonable) and use it in assert messages that currently print the
raw vector number.

Co-developed-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Chao Gao <chao.gao@intel.com>
Link: https://lore.kernel.org/r/20250919223258.1604852-45-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: sean-jc

tools/testing/selftests/kvm/include/x86/processor.h

@@ -34,6 +34,8 @@ extern uint64_t guest_tsc_khz;
 
 #define NMI_VECTOR		0x02
 
+const char *ex_str(int vector);
+
 #define X86_EFLAGS_FIXED	 (1u << 1)
 
 #define X86_CR4_VME		(1ul << 0)

tools/testing/selftests/kvm/lib/x86/processor.c

@@ -24,6 +24,39 @@ bool host_cpu_is_intel;
 bool is_forced_emulation_enabled;
 uint64_t guest_tsc_khz;
 
+const char *ex_str(int vector)
+{
+	switch (vector) {
+#define VEC_STR(v) case v##_VECTOR: return "#" #v
+	case DE_VECTOR: return "no exception";
+	case KVM_MAGIC_DE_VECTOR: return "#DE";
+	VEC_STR(DB);
+	VEC_STR(NMI);
+	VEC_STR(BP);
+	VEC_STR(OF);
+	VEC_STR(BR);
+	VEC_STR(UD);
+	VEC_STR(NM);
+	VEC_STR(DF);
+	VEC_STR(TS);
+	VEC_STR(NP);
+	VEC_STR(SS);
+	VEC_STR(GP);
+	VEC_STR(PF);
+	VEC_STR(MF);
+	VEC_STR(AC);
+	VEC_STR(MC);
+	VEC_STR(XM);
+	VEC_STR(VE);
+	VEC_STR(CP);
+	VEC_STR(HV);
+	VEC_STR(VC);
+	VEC_STR(SX);
+	default: return "#??";
+#undef VEC_STR
+	}
+}
+
 static void regs_dump(FILE *stream, struct kvm_regs *regs, uint8_t indent)
 {
 	fprintf(stream, "%*srax: 0x%.16llx rbx: 0x%.16llx "

tools/testing/selftests/kvm/x86/hyperv_features.c

@@ -54,12 +54,12 @@ static void guest_msr(struct msr_data *msr)
 
 	if (msr->fault_expected)
 		__GUEST_ASSERT(vector == GP_VECTOR,
-			       "Expected #GP on %sMSR(0x%x), got vector '0x%x'",
-			       msr->write ? "WR" : "RD", msr->idx, vector);
+			       "Expected #GP on %sMSR(0x%x), got %s",
+			       msr->write ? "WR" : "RD", msr->idx, ex_str(vector));
 	else
 		__GUEST_ASSERT(!vector,
-			       "Expected success on %sMSR(0x%x), got vector '0x%x'",
-			       msr->write ? "WR" : "RD", msr->idx, vector);
+			       "Expected success on %sMSR(0x%x), got %s",
+			       msr->write ? "WR" : "RD", msr->idx, ex_str(vector));
 
 	if (vector || is_write_only_msr(msr->idx))
 		goto done;
@@ -102,12 +102,12 @@ static void guest_hcall(vm_vaddr_t pgs_gpa, struct hcall_data *hcall)
 	vector = __hyperv_hypercall(hcall->control, input, output, &res);
 	if (hcall->ud_expected) {
 		__GUEST_ASSERT(vector == UD_VECTOR,
-			       "Expected #UD for control '%lu', got vector '0x%x'",
-			       hcall->control, vector);
+			       "Expected #UD for control '%lu', got %s",
+			       hcall->control, ex_str(vector));
 	} else {
 		__GUEST_ASSERT(!vector,
-			       "Expected no exception for control '%lu', got vector '0x%x'",
-			       hcall->control, vector);
+			       "Expected no exception for control '%lu', got %s",
+			       hcall->control, ex_str(vector));
 		GUEST_ASSERT_EQ(res, hcall->expect);
 	}
 

tools/testing/selftests/kvm/x86/monitor_mwait_test.c

@@ -30,12 +30,12 @@ do {									\
 									\
 	if (fault_wanted)						\
 		__GUEST_ASSERT((vector) == UD_VECTOR,			\
-			       "Expected #UD on " insn " for testcase '0x%x', got '0x%x'", \
-			       testcase, vector);			\
+			       "Expected #UD on " insn " for testcase '0x%x', got %s", \
+			       testcase, ex_str(vector));		\
 	else								\
 		__GUEST_ASSERT(!(vector),				\
-			       "Expected success on " insn " for testcase '0x%x', got '0x%x'", \
-			       testcase, vector);			\
+			       "Expected success on " insn " for testcase '0x%x', got %s", \
+			       testcase, ex_str(vector));		\
 } while (0)
 
 static void guest_monitor_wait(void *arg)

tools/testing/selftests/kvm/x86/pmu_counters_test.c

@@ -363,8 +363,8 @@ static void test_arch_events(uint8_t pmu_version, uint64_t perf_capabilities,
 
 #define GUEST_ASSERT_PMC_MSR_ACCESS(insn, msr, expect_gp, vector)		\
 __GUEST_ASSERT(expect_gp ? vector == GP_VECTOR : !vector,			\
-	       "Expected %s on " #insn "(0x%x), got vector %u",			\
-	       expect_gp ? "#GP" : "no fault", msr, vector)			\
+	       "Expected %s on " #insn "(0x%x), got %s",			\
+	       expect_gp ? "#GP" : "no fault", msr, ex_str(vector))		\
 
 #define GUEST_ASSERT_PMC_VALUE(insn, msr, val, expected)			\
 	__GUEST_ASSERT(val == expected,					\

tools/testing/selftests/kvm/x86/vmx_pmu_caps_test.c

@@ -57,8 +57,8 @@ static void guest_test_perf_capabilities_gp(uint64_t val)
 	uint8_t vector = wrmsr_safe(MSR_IA32_PERF_CAPABILITIES, val);
 
 	__GUEST_ASSERT(vector == GP_VECTOR,
-		       "Expected #GP for value '0x%lx', got vector '0x%x'",
-		       val, vector);
+		       "Expected #GP for value '0x%lx', got %s",
+		       val, ex_str(vector));
 }
 
 static void guest_code(uint64_t current_val)

tools/testing/selftests/kvm/x86/xcr0_cpuid_test.c

@@ -81,22 +81,22 @@ static void guest_code(void)
 
 	vector = xsetbv_safe(0, XFEATURE_MASK_FP);
 	__GUEST_ASSERT(!vector,
-		       "Expected success on XSETBV(FP), got vector '0x%x'",
-		       vector);
+		       "Expected success on XSETBV(FP), got %s",
+		       ex_str(vector));
 
 	vector = xsetbv_safe(0, supported_xcr0);
 	__GUEST_ASSERT(!vector,
-		       "Expected success on XSETBV(0x%lx), got vector '0x%x'",
-		       supported_xcr0, vector);
+		       "Expected success on XSETBV(0x%lx), got %s",
+		       supported_xcr0, ex_str(vector));
 
 	for (i = 0; i < 64; i++) {
 		if (supported_xcr0 & BIT_ULL(i))
 			continue;
 
 		vector = xsetbv_safe(0, supported_xcr0 | BIT_ULL(i));
 		__GUEST_ASSERT(vector == GP_VECTOR,
-			       "Expected #GP on XSETBV(0x%llx), supported XCR0 = %lx, got vector '0x%x'",
-			       BIT_ULL(i), supported_xcr0, vector);
+			       "Expected #GP on XSETBV(0x%llx), supported XCR0 = %lx, got %s",
+			       BIT_ULL(i), supported_xcr0, ex_str(vector));
 	}
 
 	GUEST_DONE();