hv: coding style: refine cpu related function to one exit

2) Fix procedure has more than one exit point.

Tracked-On: #861
Signed-off-by: Li, Fei1 <fei1.li@intel.com>

hypervisor/arch/x86/cpu.c

@@ -31,7 +31,7 @@ static uint64_t start_tsc __attribute__((__section__(".bss_noinit")));
 static void init_percpu_lapic_id(void)
 {
 	uint16_t i;
-	uint16_t pcpu_num = 0U;
+	uint16_t pcpu_num;
 	uint32_t lapic_id_array[CONFIG_MAX_PCPU_NUM];
 
 	/* Save all lapic_id detected via parse_mdt in lapic_id_array */
@@ -68,8 +68,10 @@ static void cpu_set_current_state(uint16_t pcpu_id, enum pcpu_boot_state state)
 	per_cpu(boot_state, pcpu_id) = state;
 }
 
-void init_cpu_pre(uint16_t pcpu_id)
+void init_cpu_pre(uint16_t pcpu_id_args)
 {
+	uint16_t pcpu_id = pcpu_id_args;
+
 	if (pcpu_id == BOOT_CPU_ID) {
 		start_tsc = rdtsc();
 
@@ -190,14 +192,16 @@ void init_cpu_post(uint16_t pcpu_id)
 static uint16_t get_cpu_id_from_lapic_id(uint32_t lapic_id)
 {
 	uint16_t i;
+	uint16_t pcpu_id = INVALID_CPU_ID;
 
 	for (i = 0U; (i < phys_cpu_num) && (i < CONFIG_MAX_PCPU_NUM); i++) {
 		if (per_cpu(lapic_id, i) == lapic_id) {
-			return i;
+			pcpu_id = i;
+			break;
 		}
 	}
 
-	return INVALID_CPU_ID;
+	return pcpu_id;
 }
 
 static void start_cpu(uint16_t pcpu_id)

hypervisor/arch/x86/cpu_caps.c

@@ -53,17 +53,19 @@ bool cpu_has_cap(uint32_t bit)
 
 bool has_monitor_cap(void)
 {
+	bool ret = false;
+
 	if (cpu_has_cap(X86_FEATURE_MONITOR)) {
 		/* don't use monitor for CPU (family: 0x6 model: 0x5c)
 		 * in hypervisor, but still expose it to the guests and
 		 * let them handle it correctly
 		 */
 		if ((boot_cpu_data.family != 0x6U) || (boot_cpu_data.model != 0x5cU)) {
-			return true;
+			ret = true;
 		}
 	}
 
-	return false;
+	return ret;
 }
 
 static inline bool is_fast_string_erms_supported_and_enabled(void)
@@ -133,27 +135,16 @@ static void detect_apicv_cap(void)
 	uint64_t msr_val;
 
 	msr_val = msr_read(MSR_IA32_VMX_PROCBASED_CTLS);
+	/* must support TPR shadow */
 	if (is_ctrl_setting_allowed(msr_val, VMX_PROCBASED_CTLS_TPR_SHADOW)) {
 		features |= VAPIC_FEATURE_TPR_SHADOW;
-	} else {
-		/* must support TPR shadow */
-		return;
-	}
 
 		msr_val = msr_read(MSR_IA32_VMX_PROCBASED_CTLS2);
+		/* must support APICV access */
 		if (is_ctrl_setting_allowed(msr_val, VMX_PROCBASED_CTLS2_VAPIC)) {
 			features |= VAPIC_FEATURE_VIRT_ACCESS;
 			if (is_ctrl_setting_allowed(msr_val, VMX_PROCBASED_CTLS2_VAPIC_REGS)) {
 				features |= VAPIC_FEATURE_VIRT_REG;
-		} else {
-			/* platform may only support APICV access */
-			cpu_caps.apicv_features = features;
-			return;
-		}
-	} else {
-		/* must support APICV access */
-		return;
-	}
 
 				if (is_ctrl_setting_allowed(msr_val, VMX_PROCBASED_CTLS2_VX2APIC)) {
 					features |= VAPIC_FEATURE_VX2APIC_MODE;
@@ -163,12 +154,17 @@ static void detect_apicv_cap(void)
 					features |= VAPIC_FEATURE_INTR_DELIVERY;
 
 					msr_val = msr_read(MSR_IA32_VMX_PINBASED_CTLS);
-		if (is_ctrl_setting_allowed(msr_val,
+					if (is_ctrl_setting_allowed(msr_val, VMX_PINBASED_CTLS_POST_IRQ)) {
-						VMX_PINBASED_CTLS_POST_IRQ)) {
 						features |= VAPIC_FEATURE_POST_INTR;
 					}
 				}
 				cpu_caps.apicv_features = features;
+			} else {
+				/* platform may only support APICV access */
+				cpu_caps.apicv_features = features;
+			}
+		}
+	}
 }
 
 static void detect_vmx_mmu_cap(void)
@@ -360,93 +356,62 @@ int32_t detect_hardware_support(void)
 	/* Long Mode (x86-64, 64-bit support) */
 	if (!cpu_has_cap(X86_FEATURE_LM)) {
 		pr_fatal("%s, LM not supported\n", __func__);
-		return -ENODEV;
+		ret = -ENODEV;
-	}
+	} else if ((boot_cpu_data.phys_bits == 0U) ||
-	if ((boot_cpu_data.phys_bits == 0U) ||
 		(boot_cpu_data.virt_bits == 0U)) {
-		pr_fatal("%s, can't detect Linear/Physical Address size\n",
+		pr_fatal("%s, can't detect Linear/Physical Address size\n", __func__);
-			__func__);
+		ret = -ENODEV;
-		return -ENODEV;
+	} else if (!cpu_has_cap(X86_FEATURE_TSC_DEADLINE)) {
-	}
-
 		/* lapic TSC deadline timer */
-	if (!cpu_has_cap(X86_FEATURE_TSC_DEADLINE)) {
 		pr_fatal("%s, TSC deadline not supported\n", __func__);
-		return -ENODEV;
+		ret = -ENODEV;
-	}
+	} else if (!cpu_has_cap(X86_FEATURE_NX)) {
-
 		/* Execute Disable */
-	if (!cpu_has_cap(X86_FEATURE_NX)) {
 		pr_fatal("%s, NX not supported\n", __func__);
-		return -ENODEV;
+		ret = -ENODEV;
-	}
+	} else if (!cpu_has_cap(X86_FEATURE_SMEP)) {
-
 		/* Supervisor-Mode Execution Prevention */
-	if (!cpu_has_cap(X86_FEATURE_SMEP)) {
 		pr_fatal("%s, SMEP not supported\n", __func__);
-		return -ENODEV;
+		ret = -ENODEV;
-	}
+	} else if (!cpu_has_cap(X86_FEATURE_SMAP)) {
-
 		/* Supervisor-Mode Access Prevention */
-	if (!cpu_has_cap(X86_FEATURE_SMAP)) {
 		pr_fatal("%s, SMAP not supported\n", __func__);
-		return -ENODEV;
+		ret = -ENODEV;
-	}
+	} else if (!cpu_has_cap(X86_FEATURE_MTRR)) {
-
-	if (!cpu_has_cap(X86_FEATURE_MTRR)) {
 		pr_fatal("%s, MTRR not supported\n", __func__);
-		return -ENODEV;
+		ret = -ENODEV;
-	}
+	} else if (!cpu_has_cap(X86_FEATURE_PAGE1GB)) {
-
-	if (!cpu_has_cap(X86_FEATURE_PAGE1GB)) {
 		pr_fatal("%s, not support 1GB page\n", __func__);
-		return -ENODEV;
+		ret = -ENODEV;
-	}
+	} else if (!cpu_has_cap(X86_FEATURE_VMX)) {
-
-	if (!cpu_has_cap(X86_FEATURE_VMX)) {
 		pr_fatal("%s, vmx not supported\n", __func__);
-		return -ENODEV;
+		ret = -ENODEV;
-	}
+	} else if (!is_fast_string_erms_supported_and_enabled()) {
-
+		ret = -ENODEV;
-	if (!is_fast_string_erms_supported_and_enabled()) {
+	} else if (!cpu_has_vmx_unrestricted_guest_cap()) {
-		return -ENODEV;
-	}
-
-	if (!cpu_has_vmx_unrestricted_guest_cap()) {
 		pr_fatal("%s, unrestricted guest not supported\n", __func__);
-		return -ENODEV;
+		ret = -ENODEV;
-	}
+	} else if (!is_ept_supported()) {
-
-	if (!is_ept_supported()) {
 		pr_fatal("%s, EPT not supported\n", __func__);
-		return -ENODEV;
+		ret = -ENODEV;
-	}
+	} else if (!is_apicv_supported()) {
-
-	if (!is_apicv_supported()) {
 		pr_fatal("%s, APICV not supported\n", __func__);
-		return -ENODEV;
+		ret = -ENODEV;
-	}
+	} else if (boot_cpu_data.cpuid_level < 0x15U) {
-
-	if (boot_cpu_data.cpuid_level < 0x15U) {
 		pr_fatal("%s, required CPU feature not supported\n", __func__);
-		return -ENODEV;
+		ret = -ENODEV;
-	}
+	} else if (is_vmx_disabled()) {
-
-	if (is_vmx_disabled()) {
 		pr_fatal("%s, VMX can not be enabled\n", __func__);
-		return -ENODEV;
+		ret = -ENODEV;
-	}
+	} else if (phys_cpu_num > CONFIG_MAX_PCPU_NUM) {
-
-	if (phys_cpu_num > CONFIG_MAX_PCPU_NUM) {
 		pr_fatal("%s, pcpu number(%d) is out of range\n", __func__, phys_cpu_num);
-		return -ENODEV;
+		ret = -ENODEV;
+	} else {
+		ret = check_vmx_mmu_cap();
+		if (ret == 0) {
+			pr_acrnlog("hardware support HV");
+		}
 	}
 
-	ret = check_vmx_mmu_cap();
-	if (ret != 0) {
 	return ret;
 }
-
-	pr_acrnlog("hardware support HV");
-	return 0;
-}

hypervisor/arch/x86/security.c

@@ -51,6 +51,7 @@ int32_t get_ibrs_type(void)
 
 bool check_cpu_security_cap(void)
 {
+	bool ret = true;
 	uint64_t x86_arch_capabilities;
 
 	detect_ibrs();
@@ -59,20 +60,18 @@ bool check_cpu_security_cap(void)
 		x86_arch_capabilities = msr_read(MSR_IA32_ARCH_CAPABILITIES);
 		skip_l1dfl_vmentry = ((x86_arch_capabilities
 			& IA32_ARCH_CAP_SKIP_L1DFL_VMENTRY) != 0UL);
-	} else {
-		return false;
-	}
 
 		if ((!cpu_has_cap(X86_FEATURE_L1D_FLUSH)) && (!skip_l1dfl_vmentry)) {
-		return false;
+			ret = false;
-	}
+		} else if ((!cpu_has_cap(X86_FEATURE_IBRS_IBPB)) &&
-
-	if ((!cpu_has_cap(X86_FEATURE_IBRS_IBPB)) &&
 			(!cpu_has_cap(X86_FEATURE_STIBP))) {
-		return false;
+			ret = false;
+		}
+	} else {
+		ret = false;
 	}
 
-	return true;
+	return ret;
 }
 
 void cpu_l1d_flush(void)

hypervisor/include/arch/x86/cpu.h

@@ -251,7 +251,7 @@ void cpu_do_idle(void);
 void cpu_dead(void);
 void trampoline_start16(void);
 void load_cpu_state_data(void);
-void init_cpu_pre(uint16_t pcpu_id);
+void init_cpu_pre(uint16_t pcpu_id_args);
 void init_cpu_post(uint16_t pcpu_id);
 void start_cpus(void);
 void stop_cpus(void);