LXR linux/tools/testing/selftests/kvm/x86_64/set_sregs

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * KVM_SET_SREGS tests
   4 *
   5 * Copyright (C) 2018, Google LLC.
   6 *
   7 * This is a regression test for the bug fixed by the following commit:
   8 * d3802286fa0f ("kvm: x86: Disallow illegal IA32_APIC_BASE MSR values")
   9 *
  10 * That bug allowed a user-mode program that called the KVM_SET_SREGS
  11 * ioctl to put a VCPU's local APIC into an invalid state.
  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
  22#include "kvm_util.h"
  23#include "processor.h"
  24
  25#define VCPU_ID                  5
  26
  27static void test_cr4_feature_bit(struct kvm_vm *vm, struct kvm_sregs *orig,
  28                                 uint64_t feature_bit)
  29{
  30        struct kvm_sregs sregs;
  31        int rc;
  32
  33        /* Skip the sub-test, the feature is supported. */
  34        if (orig->cr4 & feature_bit)
  35                return;
  36
  37        memcpy(&sregs, orig, sizeof(sregs));
  38        sregs.cr4 |= feature_bit;
  39
  40        rc = _vcpu_sregs_set(vm, VCPU_ID, &sregs);
  41        TEST_ASSERT(rc, "KVM allowed unsupported CR4 bit (0x%lx)", feature_bit);
  42
  43        /* Sanity check that KVM didn't change anything. */
  44        vcpu_sregs_get(vm, VCPU_ID, &sregs);
  45        TEST_ASSERT(!memcmp(&sregs, orig, sizeof(sregs)), "KVM modified sregs");
  46}
  47
  48static uint64_t calc_cr4_feature_bits(struct kvm_vm *vm)
  49{
  50        struct kvm_cpuid_entry2 *cpuid_1, *cpuid_7;
  51        uint64_t cr4;
  52
  53        cpuid_1 = kvm_get_supported_cpuid_entry(1);
  54        cpuid_7 = kvm_get_supported_cpuid_entry(7);
  55
  56        cr4 = X86_CR4_VME | X86_CR4_PVI | X86_CR4_TSD | X86_CR4_DE |
  57              X86_CR4_PSE | X86_CR4_PAE | X86_CR4_MCE | X86_CR4_PGE |
  58              X86_CR4_PCE | X86_CR4_OSFXSR | X86_CR4_OSXMMEXCPT;
  59        if (cpuid_7->ecx & CPUID_UMIP)
  60                cr4 |= X86_CR4_UMIP;
  61        if (cpuid_7->ecx & CPUID_LA57)
  62                cr4 |= X86_CR4_LA57;
  63        if (cpuid_1->ecx & CPUID_VMX)
  64                cr4 |= X86_CR4_VMXE;
  65        if (cpuid_1->ecx & CPUID_SMX)
  66                cr4 |= X86_CR4_SMXE;
  67        if (cpuid_7->ebx & CPUID_FSGSBASE)
  68                cr4 |= X86_CR4_FSGSBASE;
  69        if (cpuid_1->ecx & CPUID_PCID)
  70                cr4 |= X86_CR4_PCIDE;
  71        if (cpuid_1->ecx & CPUID_XSAVE)
  72                cr4 |= X86_CR4_OSXSAVE;
  73        if (cpuid_7->ebx & CPUID_SMEP)
  74                cr4 |= X86_CR4_SMEP;
  75        if (cpuid_7->ebx & CPUID_SMAP)
  76                cr4 |= X86_CR4_SMAP;
  77        if (cpuid_7->ecx & CPUID_PKU)
  78                cr4 |= X86_CR4_PKE;
  79
  80        return cr4;
  81}
  82
  83int main(int argc, char *argv[])
  84{
  85        struct kvm_sregs sregs;
  86        struct kvm_vm *vm;
  87        uint64_t cr4;
  88        int rc;
  89
  90        /* Tell stdout not to buffer its content */
  91        setbuf(stdout, NULL);
  92
  93        /*
  94         * Create a dummy VM, specifically to avoid doing KVM_SET_CPUID2, and
  95         * use it to verify all supported CR4 bits can be set prior to defining
  96         * the vCPU model, i.e. without doing KVM_SET_CPUID2.
  97         */
  98        vm = vm_create(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES, O_RDWR);
  99        vm_vcpu_add(vm, VCPU_ID);
 100
 101        vcpu_sregs_get(vm, VCPU_ID, &sregs);
 102
 103        sregs.cr4 |= calc_cr4_feature_bits(vm);
 104        cr4 = sregs.cr4;
 105
 106        rc = _vcpu_sregs_set(vm, VCPU_ID, &sregs);
 107        TEST_ASSERT(!rc, "Failed to set supported CR4 bits (0x%lx)", cr4);
 108
 109        vcpu_sregs_get(vm, VCPU_ID, &sregs);
 110        TEST_ASSERT(sregs.cr4 == cr4, "sregs.CR4 (0x%llx) != CR4 (0x%lx)",
 111                    sregs.cr4, cr4);
 112
 113        /* Verify all unsupported features are rejected by KVM. */
 114        test_cr4_feature_bit(vm, &sregs, X86_CR4_UMIP);
 115        test_cr4_feature_bit(vm, &sregs, X86_CR4_LA57);
 116        test_cr4_feature_bit(vm, &sregs, X86_CR4_VMXE);
 117        test_cr4_feature_bit(vm, &sregs, X86_CR4_SMXE);
 118        test_cr4_feature_bit(vm, &sregs, X86_CR4_FSGSBASE);
 119        test_cr4_feature_bit(vm, &sregs, X86_CR4_PCIDE);
 120        test_cr4_feature_bit(vm, &sregs, X86_CR4_OSXSAVE);
 121        test_cr4_feature_bit(vm, &sregs, X86_CR4_SMEP);
 122        test_cr4_feature_bit(vm, &sregs, X86_CR4_SMAP);
 123        test_cr4_feature_bit(vm, &sregs, X86_CR4_PKE);
 124        kvm_vm_free(vm);
 125
 126        /* Create a "real" VM and verify APIC_BASE can be set. */
 127        vm = vm_create_default(VCPU_ID, 0, NULL);
 128
 129        vcpu_sregs_get(vm, VCPU_ID, &sregs);
 130        sregs.apic_base = 1 << 10;
 131        rc = _vcpu_sregs_set(vm, VCPU_ID, &sregs);
 132        TEST_ASSERT(rc, "Set IA32_APIC_BASE to %llx (invalid)",
 133                    sregs.apic_base);
 134        sregs.apic_base = 1 << 11;
 135        rc = _vcpu_sregs_set(vm, VCPU_ID, &sregs);
 136        TEST_ASSERT(!rc, "Couldn't set IA32_APIC_BASE to %llx (valid)",
 137                    sregs.apic_base);
 138
 139        kvm_vm_free(vm);
 140
 141        return 0;
 142}
 143