Commit 5efde6d7 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: selftests: Refactor stable TSC check to use TEST_REQUIRE() 

Refactor the nested TSC scaling test's check on a stable system TSC to
use TEST_REQUIRE() to do the heavy lifting when the system doesn't have
a stable TSC.  Using a helper+TEST_REQUIRE() eliminates the need for
gotos and a custom message.

Cc: Hao Ge <gehao@kylinos.cn>
Cc: Vipin Sharma <vipinsh@google.com>
Link: https://lore.kernel.org/r/20230406001724.706668-1-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent b9846a69

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

+7 −15
Original line number Diff line number Diff line
@@ -116,29 +116,21 @@ static void l1_guest_code(struct vmx_pages *vmx_pages) 
	GUEST_DONE();

}



static void stable_tsc_check_supported(void)

static bool system_has_stable_tsc(void)

{

	bool tsc_is_stable;

	FILE *fp;

	char buf[4];



	fp = fopen("/sys/devices/system/clocksource/clocksource0/current_clocksource", "r");

	if (fp == NULL)

		goto skip_test;

		return false;



	if (fgets(buf, sizeof(buf), fp) == NULL)

		goto close_fp;

	tsc_is_stable = fgets(buf, sizeof(buf), fp) &&

			!strncmp(buf, "tsc", sizeof(buf));



	if (strncmp(buf, "tsc", sizeof(buf)))

		goto close_fp;



	fclose(fp);

	return;



close_fp:

	fclose(fp);

skip_test:

	print_skip("Kernel does not use TSC clocksource - assuming that host TSC is not stable");

	exit(KSFT_SKIP);

	return tsc_is_stable;

}



int main(int argc, char *argv[])
@@ -156,7 +148,7 @@ int main(int argc, char *argv[]) 


	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));

	TEST_REQUIRE(kvm_has_cap(KVM_CAP_TSC_CONTROL));

	stable_tsc_check_supported();

	TEST_REQUIRE(system_has_stable_tsc());



	/*

	 * We set L1's scale factor to be a random number from 2 to 10.