tools/testing/selftests/kvm/platform_info_test.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Test for x86 KVM_CAP_MSR_PLATFORM_INFO
   4  *
   5  * Copyright (C) 2018, Google LLC.
   6  *
   7  * This work is licensed under the terms of the GNU GPL, version 2.
   8  *
   9  * Verifies expected behavior of controlling guest access to
  10  * MSR_PLATFORM_INFO.
  11  */
  12
  13 #define _GNU_SOURCE /* for program_invocation_short_name */
  14 #include <fcntl.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <sys/ioctl.h>
  19
  20 #include "test_util.h"
  21 #include "kvm_util.h"
  22 #include "x86.h"
  23
  24 #define VCPU_ID 0
  25 #define MSR_PLATFORM_INFO_MAX_TURBO_RATIO 0xff00
  26
  27 static void guest_code(void)
  28 {
  29         uint64_t msr_platform_info;
  30
  31         for (;;) {
  32                 msr_platform_info = rdmsr(MSR_PLATFORM_INFO);
  33                 GUEST_SYNC(msr_platform_info);
  34                 asm volatile ("inc %r11");
  35         }
  36 }
  37
  38 static void set_msr_platform_info_enabled(struct kvm_vm *vm, bool enable)
  39 {
  40         struct kvm_enable_cap cap = {};
  41
  42         cap.cap = KVM_CAP_MSR_PLATFORM_INFO;
  43         cap.flags = 0;
  44         cap.args[0] = (int)enable;
  45         vm_enable_cap(vm, &cap);
  46 }
  47
  48 static void test_msr_platform_info_enabled(struct kvm_vm *vm)
  49 {
  50         struct kvm_run *run = vcpu_state(vm, VCPU_ID);
  51         struct guest_args args;
  52
  53         set_msr_platform_info_enabled(vm, true);
  54         vcpu_run(vm, VCPU_ID);
  55         TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
  56                         "Exit_reason other than KVM_EXIT_IO: %u (%s),\n",
  57                         run->exit_reason,
  58                         exit_reason_str(run->exit_reason));
  59         guest_args_read(vm, VCPU_ID, &args);
  60         TEST_ASSERT(args.port == GUEST_PORT_SYNC,
  61                         "Received IO from port other than PORT_HOST_SYNC: %u\n",
  62                         run->io.port);
  63         TEST_ASSERT((args.arg1 & MSR_PLATFORM_INFO_MAX_TURBO_RATIO) ==
  64                 MSR_PLATFORM_INFO_MAX_TURBO_RATIO,
  65                 "Expected MSR_PLATFORM_INFO to have max turbo ratio mask: %i.",
  66                 MSR_PLATFORM_INFO_MAX_TURBO_RATIO);
  67 }
  68
  69 static void test_msr_platform_info_disabled(struct kvm_vm *vm)
  70 {
  71         struct kvm_run *run = vcpu_state(vm, VCPU_ID);
  72
  73         set_msr_platform_info_enabled(vm, false);
  74         vcpu_run(vm, VCPU_ID);
  75         TEST_ASSERT(run->exit_reason == KVM_EXIT_SHUTDOWN,
  76                         "Exit_reason other than KVM_EXIT_SHUTDOWN: %u (%s)\n",
  77                         run->exit_reason,
  78                         exit_reason_str(run->exit_reason));
  79 }
  80
  81 int main(int argc, char *argv[])
  82 {
  83         struct kvm_vm *vm;
  84         struct kvm_run *state;
  85         int rv;
  86         uint64_t msr_platform_info;
  87
  88         /* Tell stdout not to buffer its content */
  89         setbuf(stdout, NULL);
  90
  91         rv = kvm_check_cap(KVM_CAP_MSR_PLATFORM_INFO);
  92         if (!rv) {
  93                 fprintf(stderr,
  94                         "KVM_CAP_MSR_PLATFORM_INFO not supported, skip test\n");
  95                 exit(KSFT_SKIP);
  96         }
  97
  98         vm = vm_create_default(VCPU_ID, 0, guest_code);
  99
 100         msr_platform_info = vcpu_get_msr(vm, VCPU_ID, MSR_PLATFORM_INFO);
 101         vcpu_set_msr(vm, VCPU_ID, MSR_PLATFORM_INFO,
 102                 msr_platform_info | MSR_PLATFORM_INFO_MAX_TURBO_RATIO);
 103         test_msr_platform_info_enabled(vm);
 104         test_msr_platform_info_disabled(vm);
 105         vcpu_set_msr(vm, VCPU_ID, MSR_PLATFORM_INFO, msr_platform_info);
 106
 107         kvm_vm_free(vm);
 108
 109         return 0;
 110 }