1 files changed, 110 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/platform_info_test.c b/tools/testing/selftests/kvm/platform_info_test.c
new file mode 100644
index 000000000000..3764e7121265
--- /dev/null
+++ b/tools/testing/selftests/kvm/platform_info_test.c
@@ -0,0 +1,110 @@
+// 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.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#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 "x86.h"
+
+#define VCPU_ID 0
+#define MSR_PLATFORM_INFO_MAX_TURBO_RATIO 0xff00
+
+static void guest_code(void)
+{
+	uint64_t msr_platform_info;
+
+	for (;;) {
+		msr_platform_info = rdmsr(MSR_PLATFORM_INFO);
+		GUEST_SYNC(msr_platform_info);
+		asm volatile ("inc %r11");
+	}
+}
+
+static void set_msr_platform_info_enabled(struct kvm_vm *vm, bool enable)
+{
+	struct kvm_enable_cap cap = {};
+
+	cap.cap = KVM_CAP_MSR_PLATFORM_INFO;
+	cap.flags = 0;
+	cap.args[0] = (int)enable;
+	vm_enable_cap(vm, &cap);
+}
+
+static void test_msr_platform_info_enabled(struct kvm_vm *vm)
+{
+	struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+	struct guest_args args;
+
+	set_msr_platform_info_enabled(vm, true);
+	vcpu_run(vm, VCPU_ID);
+	TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+			"Exit_reason other than KVM_EXIT_IO: %u (%s),\n",
+			run->exit_reason,
+			exit_reason_str(run->exit_reason));
+	guest_args_read(vm, VCPU_ID, &args);
+	TEST_ASSERT(args.port == GUEST_PORT_SYNC,
+			"Received IO from port other than PORT_HOST_SYNC: %u\n",
+			run->io.port);
+	TEST_ASSERT((args.arg1 & MSR_PLATFORM_INFO_MAX_TURBO_RATIO) ==
+		MSR_PLATFORM_INFO_MAX_TURBO_RATIO,
+		"Expected MSR_PLATFORM_INFO to have max turbo ratio mask: %i.",
+		MSR_PLATFORM_INFO_MAX_TURBO_RATIO);
+}
+
+static void test_msr_platform_info_disabled(struct kvm_vm *vm)
+{
+	struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+
+	set_msr_platform_info_enabled(vm, false);
+	vcpu_run(vm, VCPU_ID);
+	TEST_ASSERT(run->exit_reason == KVM_EXIT_SHUTDOWN,
+			"Exit_reason other than KVM_EXIT_SHUTDOWN: %u (%s)\n",
+			run->exit_reason,
+			exit_reason_str(run->exit_reason));
+}
+
+int main(int argc, char *argv[])
+{
+	struct kvm_vm *vm;
+	struct kvm_run *state;
+	int rv;
+	uint64_t msr_platform_info;
+
+	/* Tell stdout not to buffer its content */
+	setbuf(stdout, NULL);
+
+	rv = kvm_check_cap(KVM_CAP_MSR_PLATFORM_INFO);
+	if (!rv) {
+		fprintf(stderr,
+			"KVM_CAP_MSR_PLATFORM_INFO not supported, skip test\n");
+		exit(KSFT_SKIP);
+	}
+
+	vm = vm_create_default(VCPU_ID, 0, guest_code);
+
+	msr_platform_info = vcpu_get_msr(vm, VCPU_ID, MSR_PLATFORM_INFO);
+	vcpu_set_msr(vm, VCPU_ID, MSR_PLATFORM_INFO,
+		msr_platform_info | MSR_PLATFORM_INFO_MAX_TURBO_RATIO);
+	test_msr_platform_info_disabled(vm);
+	test_msr_platform_info_enabled(vm);
+	vcpu_set_msr(vm, VCPU_ID, MSR_PLATFORM_INFO, msr_platform_info);
+
+	kvm_vm_free(vm);
+
+	return 0;
+}