Commit 80fd6635 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

selftests: kvm: revamp MONITOR/MWAIT tests 



Run each testcase in a separate VMs to cover more possibilities;
move WRMSR close to MONITOR/MWAIT to test updating CPUID bits
while in the VM.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 782f9fea

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

+57 −51
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 


#include "kvm_util.h"

#include "processor.h"

#include "kselftest.h"



#define CPUID_MWAIT (1u << 3)
@@ -14,6 +15,8 @@ enum monitor_mwait_testcases { 
	MWAIT_QUIRK_DISABLED = BIT(0),

	MISC_ENABLES_QUIRK_DISABLED = BIT(1),

	MWAIT_DISABLED = BIT(2),

	CPUID_DISABLED = BIT(3),

	TEST_MAX = CPUID_DISABLED * 2 - 1,

};



/*
@@ -35,11 +38,19 @@ do { \ 
			       testcase, vector);			\

} while (0)



static void guest_monitor_wait(int testcase)

static void guest_monitor_wait(void *arg)

{

	int testcase = (int) (long) arg;

	u8 vector;



	GUEST_SYNC(testcase);

	u64 val = rdmsr(MSR_IA32_MISC_ENABLE) & ~MSR_IA32_MISC_ENABLE_MWAIT;

	if (!(testcase & MWAIT_DISABLED))

		val |= MSR_IA32_MISC_ENABLE_MWAIT;

	wrmsr(MSR_IA32_MISC_ENABLE, val);



	__GUEST_ASSERT(this_cpu_has(X86_FEATURE_MWAIT) == !(testcase & MWAIT_DISABLED),

		       "Expected CPUID.MWAIT %s\n",

		       (testcase & MWAIT_DISABLED) ? "cleared" : "set");



	/*

	 * Arbitrarily MONITOR this function, SVM performs fault checks before
@@ -50,19 +61,6 @@ static void guest_monitor_wait(int testcase) 


	vector = kvm_asm_safe("mwait", "a"(guest_monitor_wait), "c"(0), "d"(0));

	GUEST_ASSERT_MONITOR_MWAIT("MWAIT", testcase, vector);

}



static void guest_code(void)

{

	guest_monitor_wait(MWAIT_DISABLED);



	guest_monitor_wait(MWAIT_QUIRK_DISABLED | MWAIT_DISABLED);



	guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED | MWAIT_DISABLED);

	guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED);



	guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED | MWAIT_QUIRK_DISABLED | MWAIT_DISABLED);

	guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED | MWAIT_QUIRK_DISABLED);



	GUEST_DONE();

}
@@ -74,56 +72,64 @@ int main(int argc, char *argv[]) 
	struct kvm_vm *vm;

	struct ucall uc;

	int testcase;

	char test[80];



	TEST_REQUIRE(this_cpu_has(X86_FEATURE_MWAIT));

	TEST_REQUIRE(kvm_has_cap(KVM_CAP_DISABLE_QUIRKS2));



	vm = vm_create_with_one_vcpu(&vcpu, guest_code);

	ksft_print_header();

	ksft_set_plan(12);

	for (testcase = 0; testcase <= TEST_MAX; testcase++) {

		vm = vm_create_with_one_vcpu(&vcpu, guest_monitor_wait);

		vcpu_args_set(vcpu, 1, (void *)(long)testcase);



		disabled_quirks = 0;

		if (testcase & MWAIT_QUIRK_DISABLED) {

			disabled_quirks |= KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS;

			strcpy(test, "MWAIT can fault");

		} else {

			strcpy(test, "MWAIT never faults");

		}

		if (testcase & MISC_ENABLES_QUIRK_DISABLED) {

			disabled_quirks |= KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT;

			strcat(test, ", MISC_ENABLE updates CPUID");

		} else {

			strcat(test, ", no CPUID updates");

		}



		vm_enable_cap(vm, KVM_CAP_DISABLE_QUIRKS2, disabled_quirks);



		if (!(testcase & MISC_ENABLES_QUIRK_DISABLED) &&

		    (!!(testcase & CPUID_DISABLED) ^ !!(testcase & MWAIT_DISABLED)))

			continue;



		if (testcase & CPUID_DISABLED) {

			strcat(test, ", CPUID clear");

			vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_MWAIT);

		} else {

			strcat(test, ", CPUID set");

			vcpu_set_cpuid_feature(vcpu, X86_FEATURE_MWAIT);

		}



		if (testcase & MWAIT_DISABLED)

			strcat(test, ", MWAIT disabled");



	while (1) {

		vcpu_run(vcpu);

		TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);



		switch (get_ucall(vcpu, &uc)) {

		case UCALL_SYNC:

			testcase = uc.args[1];

			break;

		case UCALL_ABORT:

			REPORT_GUEST_ASSERT(uc);

			goto done;

			/* Detected in vcpu_run */

			break;

		case UCALL_DONE:

			goto done;

			ksft_test_result_pass("%s\n", test);

			break;

		default:

			TEST_FAIL("Unknown ucall %lu", uc.cmd);

			goto done;

		}



		disabled_quirks = 0;

		if (testcase & MWAIT_QUIRK_DISABLED)

			disabled_quirks |= KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS;

		if (testcase & MISC_ENABLES_QUIRK_DISABLED)

			disabled_quirks |= KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT;

		vm_enable_cap(vm, KVM_CAP_DISABLE_QUIRKS2, disabled_quirks);



		/*

		 * If the MISC_ENABLES quirk (KVM neglects to update CPUID to

		 * enable/disable MWAIT) is disabled, toggle the ENABLE_MWAIT

		 * bit in MISC_ENABLES accordingly.  If the quirk is enabled,

		 * the only valid configuration is MWAIT disabled, as CPUID

		 * can't be manually changed after running the vCPU.

		 */

		if (!(testcase & MISC_ENABLES_QUIRK_DISABLED)) {

			TEST_ASSERT(testcase & MWAIT_DISABLED,

				    "Can't toggle CPUID features after running vCPU");

			continue;

			break;

		}



		vcpu_set_msr(vcpu, MSR_IA32_MISC_ENABLE,

			     (testcase & MWAIT_DISABLED) ? 0 : MSR_IA32_MISC_ENABLE_MWAIT);

		kvm_vm_free(vm);

	}

	ksft_finished();



done:

	kvm_vm_free(vm);

	return 0;

}