linux/tools/testing/selftests/kvm/x86_64/platform_info_test.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Test for x86 KVM_CAP_MSR_PLATFORM_INFO
 *
 * Copyright (C) 2018, Google LLC.
 *
 * This work is licensed under the terms of the GNU GPL, version 2.
 *
 * Verifies expected behavior of controlling guest access to
 * MSR_PLATFORM_INFO.
 */
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>

#include "test_util.h"
#include "kvm_util.h"
#include "processor.h"

#define MSR_PLATFORM_INFO_MAX_TURBO_RATIO 0xff00

static void guest_code(void)
{
	uint64_t msr_platform_info;
	uint8_t vector;

	GUEST_SYNC(true);
	msr_platform_info = rdmsr(MSR_PLATFORM_INFO);
	GUEST_ASSERT_EQ(msr_platform_info & MSR_PLATFORM_INFO_MAX_TURBO_RATIO,
			MSR_PLATFORM_INFO_MAX_TURBO_RATIO);

	GUEST_SYNC(false);
	vector = rdmsr_safe(MSR_PLATFORM_INFO, &msr_platform_info);
	GUEST_ASSERT_EQ(vector, GP_VECTOR);

	GUEST_DONE();
}

int main(int argc, char *argv[])
{
	struct kvm_vcpu *vcpu;
	struct kvm_vm *vm;
	uint64_t msr_platform_info;
	struct ucall uc;

	TEST_REQUIRE(kvm_has_cap(KVM_CAP_MSR_PLATFORM_INFO));

	vm = vm_create_with_one_vcpu(&vcpu, guest_code);

	msr_platform_info = vcpu_get_msr(vcpu, MSR_PLATFORM_INFO);
	vcpu_set_msr(vcpu, MSR_PLATFORM_INFO,
		     msr_platform_info | MSR_PLATFORM_INFO_MAX_TURBO_RATIO);

	for (;;) {
		vcpu_run(vcpu);
		TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);

		switch (get_ucall(vcpu, &uc)) {
		case UCALL_SYNC:
			vm_enable_cap(vm, KVM_CAP_MSR_PLATFORM_INFO, uc.args[1]);
			break;
		case UCALL_DONE:
			goto done;
		case UCALL_ABORT:
			REPORT_GUEST_ASSERT(uc);
		default:
			TEST_FAIL("Unexpected ucall %lu", uc.cmd);
			break;
		}
	}

done:
	vcpu_set_msr(vcpu, MSR_PLATFORM_INFO, msr_platform_info);

	kvm_vm_free(vm);

	return 0;
}