KVM: selftests: Add kvm_has_cap() to provide syntactic sugar

Add kvm_has_cap() to wrap kvm_check_cap() and return a bool for the use
cases where the caller only wants check if a capability is supported,
i.e. doesn't care about the value beyond whether or not it's non-zero.
The "check" terminology is somewhat ambiguous as the non-boolean return
suggests that '0' might mean "success", i.e. suggests that the ioctl uses
the 0/-errno pattern.  Provide a wrapper instead of trying to find a new
name for the raw helper; the "check" terminology is derived from the name
of the ioctl, so using e.g. "get" isn't a clear win.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/aarch64/get-reg-list.c

@@ -395,7 +395,7 @@ static void check_supported(struct vcpu_config *c)
 	struct reg_sublist *s;
 
 	for_each_sublist(c, s) {
-		if (s->capability && !kvm_check_cap(s->capability)) {
+		if (s->capability && !kvm_has_cap(s->capability)) {
 			fprintf(stderr, "%s: %s not available, skipping tests\n", config_name(c), s->name);
 			exit(KSFT_SKIP);
 		}

tools/testing/selftests/kvm/aarch64/vcpu_width_config.c

@@ -82,7 +82,7 @@ int main(void)
 	struct kvm_vm *vm;
 	int ret;
 
-	if (!kvm_check_cap(KVM_CAP_ARM_EL1_32BIT)) {
+	if (!kvm_has_cap(KVM_CAP_ARM_EL1_32BIT)) {
 		print_skip("KVM_CAP_ARM_EL1_32BIT is not supported");
 		exit(KSFT_SKIP);
 	}

tools/testing/selftests/kvm/dirty_log_test.c

@@ -210,7 +210,7 @@ static void sem_wait_until(sem_t *sem)
 
 static bool clear_log_supported(void)
 {
-	return kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
+	return kvm_has_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
 }
 
 static void clear_log_create_vm_done(struct kvm_vm *vm)
@@ -264,7 +264,7 @@ static void default_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err)
 
 static bool dirty_ring_supported(void)
 {
-	return kvm_check_cap(KVM_CAP_DIRTY_LOG_RING);
+	return kvm_has_cap(KVM_CAP_DIRTY_LOG_RING);
 }
 
 static void dirty_ring_create_vm_done(struct kvm_vm *vm)

tools/testing/selftests/kvm/include/kvm_util_base.h

@@ -169,6 +169,11 @@ int open_path_or_exit(const char *path, int flags);
 int open_kvm_dev_path_or_exit(void);
 unsigned int kvm_check_cap(long cap);
 
+static inline bool kvm_has_cap(long cap)
+{
+	return kvm_check_cap(cap);
+}
+
 #define __KVM_SYSCALL_ERROR(_name, _ret) \
 	"%s failed, rc: %i errno: %i (%s)", (_name), (_ret), errno, strerror(errno)
 

tools/testing/selftests/kvm/kvm_binary_stats_test.c

@@ -213,7 +213,7 @@ int main(int argc, char *argv[])
 	}
 
 	/* Check the extension for binary stats */
-	if (!kvm_check_cap(KVM_CAP_BINARY_STATS_FD)) {
+	if (!kvm_has_cap(KVM_CAP_BINARY_STATS_FD)) {
 		print_skip("Binary form statistics interface is not supported");
 		exit(KSFT_SKIP);
 	}

tools/testing/selftests/kvm/lib/kvm_util.c

@@ -80,7 +80,7 @@ unsigned int kvm_check_cap(long cap)
 
 	close(kvm_fd);
 
-	return ret;
+	return (unsigned int)ret;
 }
 
 void vm_enable_dirty_ring(struct kvm_vm *vm, uint32_t ring_size)
@@ -93,7 +93,7 @@ static void vm_open(struct kvm_vm *vm)
 {
 	vm->kvm_fd = _open_kvm_dev_path_or_exit(O_RDWR);
 
-	if (!kvm_check_cap(KVM_CAP_IMMEDIATE_EXIT)) {
+	if (!kvm_has_cap(KVM_CAP_IMMEDIATE_EXIT)) {
 		print_skip("immediate_exit not available");
 		exit(KSFT_SKIP);
 	}

tools/testing/selftests/kvm/lib/s390x/diag318_test_handler.c

@@ -61,7 +61,7 @@ uint64_t get_diag318_info(void)
 	 * If KVM does not support diag318, then return 0 to
 	 * ensure tests do not break.
 	 */
-	if (!kvm_check_cap(KVM_CAP_S390_DIAG318)) {
+	if (!kvm_has_cap(KVM_CAP_S390_DIAG318)) {
 		if (!printed_skip) {
 			fprintf(stdout, "KVM_CAP_S390_DIAG318 not supported. "
 				"Skipping diag318 test.\n");

tools/testing/selftests/kvm/x86_64/debug_regs.c

@@ -95,7 +95,7 @@ int main(void)
 		1,		/* cli */
 	};
 
-	if (!kvm_check_cap(KVM_CAP_SET_GUEST_DEBUG)) {
+	if (!kvm_has_cap(KVM_CAP_SET_GUEST_DEBUG)) {
 		print_skip("KVM_CAP_SET_GUEST_DEBUG not supported");
 		return 0;
 	}

tools/testing/selftests/kvm/x86_64/emulator_error_test.c

@@ -162,7 +162,7 @@ int main(int argc, char *argv[])
 	/* Tell stdout not to buffer its content */
 	setbuf(stdout, NULL);
 
-	if (!kvm_check_cap(KVM_CAP_SMALLER_MAXPHYADDR)) {
+	if (!kvm_has_cap(KVM_CAP_SMALLER_MAXPHYADDR)) {
 		printf("module parameter 'allow_smaller_maxphyaddr' is not set.  Skipping test.\n");
 		return 0;
 	}

tools/testing/selftests/kvm/x86_64/evmcs_test.c

@@ -209,8 +209,8 @@ int main(int argc, char *argv[])
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
 
 	if (!nested_vmx_supported() ||
-	    !kvm_check_cap(KVM_CAP_NESTED_STATE) ||
-	    !kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
+	    !kvm_has_cap(KVM_CAP_NESTED_STATE) ||
+	    !kvm_has_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
 		print_skip("Enlightened VMCS is unsupported");
 		exit(KSFT_SKIP);
 	}

tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c

@@ -137,7 +137,7 @@ int main(int argc, char *argv[])
 	/* Tell stdout not to buffer its content */
 	setbuf(stdout, NULL);
 
-	if (!kvm_check_cap(KVM_CAP_HYPERV_CPUID)) {
+	if (!kvm_has_cap(KVM_CAP_HYPERV_CPUID)) {
 		print_skip("KVM_CAP_HYPERV_CPUID not supported");
 		exit(KSFT_SKIP);
 	}
@@ -152,7 +152,7 @@ int main(int argc, char *argv[])
 	free(hv_cpuid_entries);
 
 	if (!nested_vmx_supported() ||
-	    !kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
+	    !kvm_has_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)) {
 		print_skip("Enlightened VMCS is unsupported");
 		goto do_sys;
 	}
@@ -163,7 +163,7 @@ int main(int argc, char *argv[])
 
 do_sys:
 	/* Test system ioctl version */
-	if (!kvm_check_cap(KVM_CAP_SYS_HYPERV_CPUID)) {
+	if (!kvm_has_cap(KVM_CAP_SYS_HYPERV_CPUID)) {
 		print_skip("KVM_CAP_SYS_HYPERV_CPUID not supported");
 		goto out;
 	}

tools/testing/selftests/kvm/x86_64/kvm_pv_test.c

@@ -204,7 +204,7 @@ int main(void)
 	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
 
-	if (!kvm_check_cap(KVM_CAP_ENFORCE_PV_FEATURE_CPUID)) {
+	if (!kvm_has_cap(KVM_CAP_ENFORCE_PV_FEATURE_CPUID)) {
 		print_skip("KVM_CAP_ENFORCE_PV_FEATURE_CPUID not supported");
 		exit(KSFT_SKIP);
 	}

tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c

@@ -123,7 +123,7 @@ static void check_set_bsp_busy(void)
 
 int main(int argc, char *argv[])
 {
-	if (!kvm_check_cap(KVM_CAP_SET_BOOT_CPU_ID)) {
+	if (!kvm_has_cap(KVM_CAP_SET_BOOT_CPU_ID)) {
 		print_skip("set_boot_cpu_id not available");
 		return 0;
 	}

tools/testing/selftests/kvm/x86_64/sev_migrate_tests.c

@@ -400,8 +400,8 @@ int main(int argc, char *argv[])
 {
 	struct kvm_cpuid_entry2 *cpuid;
 
-	if (!kvm_check_cap(KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM) &&
-	    !kvm_check_cap(KVM_CAP_VM_COPY_ENC_CONTEXT_FROM)) {
+	if (!kvm_has_cap(KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM) &&
+	    !kvm_has_cap(KVM_CAP_VM_COPY_ENC_CONTEXT_FROM)) {
 		print_skip("Capabilities not available");
 		exit(KSFT_SKIP);
 	}

tools/testing/selftests/kvm/x86_64/triple_fault_event_test.c

@@ -51,7 +51,7 @@ int main(void)
 		exit(KSFT_SKIP);
 	}
 
-	if (!kvm_check_cap(KVM_CAP_X86_TRIPLE_FAULT_EVENT)) {
+	if (!kvm_has_cap(KVM_CAP_X86_TRIPLE_FAULT_EVENT)) {
 		print_skip("KVM_CAP_X86_TRIPLE_FAULT_EVENT not supported");
 		exit(KSFT_SKIP);
 	}

tools/testing/selftests/kvm/x86_64/tsc_scaling_sync.c

@@ -93,7 +93,7 @@ static void *run_vcpu(void *_cpu_nr)
 
 int main(int argc, char *argv[])
 {
-        if (!kvm_check_cap(KVM_CAP_VM_TSC_CONTROL)) {
+	if (!kvm_has_cap(KVM_CAP_VM_TSC_CONTROL)) {
 		print_skip("KVM_CAP_VM_TSC_CONTROL not available");
 		exit(KSFT_SKIP);
 	}

tools/testing/selftests/kvm/x86_64/vmx_nested_tsc_scaling_test.c

@@ -118,7 +118,7 @@ static void l1_guest_code(struct vmx_pages *vmx_pages)
 
 static void tsc_scaling_check_supported(void)
 {
-	if (!kvm_check_cap(KVM_CAP_TSC_CONTROL)) {
+	if (!kvm_has_cap(KVM_CAP_TSC_CONTROL)) {
 		print_skip("TSC scaling not supported by the HW");
 		exit(KSFT_SKIP);
 	}

tools/testing/selftests/kvm/x86_64/vmx_preemption_timer_test.c

@@ -169,7 +169,7 @@ int main(int argc, char *argv[])
 	 */
 	nested_vmx_check_supported();
 
-	if (!kvm_check_cap(KVM_CAP_NESTED_STATE)) {
+	if (!kvm_has_cap(KVM_CAP_NESTED_STATE)) {
 		print_skip("KVM_CAP_NESTED_STATE not supported");
 		exit(KSFT_SKIP);
 	}

tools/testing/selftests/kvm/x86_64/vmx_set_nested_state_test.c

@@ -267,7 +267,7 @@ int main(int argc, char *argv[])
 
 	have_evmcs = kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS);
 
-	if (!kvm_check_cap(KVM_CAP_NESTED_STATE)) {
+	if (!kvm_has_cap(KVM_CAP_NESTED_STATE)) {
 		print_skip("KVM_CAP_NESTED_STATE not available");
 		exit(KSFT_SKIP);
 	}