blob: 318be0bf77ab603864fe15463b30ece4660ac142 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
* Copyright (C) 2018, Google LLC.
* This is a regression test for the bug fixed by the following commit:
* d3802286fa0f ("kvm: x86: Disallow illegal IA32_APIC_BASE MSR values")
* That bug allowed a user-mode program that called the KVM_SET_SREGS
* ioctl to put a VCPU's local APIC into an invalid state.
#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 "processor.h"
#define VCPU_ID 5
static void test_cr4_feature_bit(struct kvm_vm *vm, struct kvm_sregs *orig,
uint64_t feature_bit)
struct kvm_sregs sregs;
int rc;
/* Skip the sub-test, the feature is supported. */
if (orig->cr4 & feature_bit)
memcpy(&sregs, orig, sizeof(sregs));
sregs.cr4 |= feature_bit;
rc = _vcpu_sregs_set(vm, VCPU_ID, &sregs);
TEST_ASSERT(rc, "KVM allowed unsupported CR4 bit (0x%lx)", feature_bit);
/* Sanity check that KVM didn't change anything. */
vcpu_sregs_get(vm, VCPU_ID, &sregs);
TEST_ASSERT(!memcmp(&sregs, orig, sizeof(sregs)), "KVM modified sregs");
static uint64_t calc_cr4_feature_bits(struct kvm_vm *vm)
struct kvm_cpuid_entry2 *cpuid_1, *cpuid_7;
uint64_t cr4;
cpuid_1 = kvm_get_supported_cpuid_entry(1);
cpuid_7 = kvm_get_supported_cpuid_entry(7);
cr4 = X86_CR4_VME | X86_CR4_PVI | X86_CR4_TSD | X86_CR4_DE |
X86_CR4_PSE | X86_CR4_PAE | X86_CR4_MCE | X86_CR4_PGE |
if (cpuid_7->ecx & CPUID_UMIP)
cr4 |= X86_CR4_UMIP;
if (cpuid_7->ecx & CPUID_LA57)
cr4 |= X86_CR4_LA57;
if (cpuid_1->ecx & CPUID_VMX)
cr4 |= X86_CR4_VMXE;
if (cpuid_1->ecx & CPUID_SMX)
cr4 |= X86_CR4_SMXE;
if (cpuid_7->ebx & CPUID_FSGSBASE)
cr4 |= X86_CR4_FSGSBASE;
if (cpuid_1->ecx & CPUID_PCID)
cr4 |= X86_CR4_PCIDE;
if (cpuid_1->ecx & CPUID_XSAVE)
cr4 |= X86_CR4_OSXSAVE;
if (cpuid_7->ebx & CPUID_SMEP)
cr4 |= X86_CR4_SMEP;
if (cpuid_7->ebx & CPUID_SMAP)
cr4 |= X86_CR4_SMAP;
if (cpuid_7->ecx & CPUID_PKU)
cr4 |= X86_CR4_PKE;
return cr4;
int main(int argc, char *argv[])
struct kvm_sregs sregs;
struct kvm_vm *vm;
uint64_t cr4;
int rc;
/* Tell stdout not to buffer its content */
setbuf(stdout, NULL);
* Create a dummy VM, specifically to avoid doing KVM_SET_CPUID2, and
* use it to verify all supported CR4 bits can be set prior to defining
* the vCPU model, i.e. without doing KVM_SET_CPUID2.
vm_vcpu_add(vm, VCPU_ID);
vcpu_sregs_get(vm, VCPU_ID, &sregs);
sregs.cr4 |= calc_cr4_feature_bits(vm);
cr4 = sregs.cr4;
rc = _vcpu_sregs_set(vm, VCPU_ID, &sregs);
TEST_ASSERT(!rc, "Failed to set supported CR4 bits (0x%lx)", cr4);
vcpu_sregs_get(vm, VCPU_ID, &sregs);
TEST_ASSERT(sregs.cr4 == cr4, "sregs.CR4 (0x%llx) != CR4 (0x%lx)",
sregs.cr4, cr4);
/* Verify all unsupported features are rejected by KVM. */
test_cr4_feature_bit(vm, &sregs, X86_CR4_UMIP);
test_cr4_feature_bit(vm, &sregs, X86_CR4_LA57);
test_cr4_feature_bit(vm, &sregs, X86_CR4_VMXE);
test_cr4_feature_bit(vm, &sregs, X86_CR4_SMXE);
test_cr4_feature_bit(vm, &sregs, X86_CR4_FSGSBASE);
test_cr4_feature_bit(vm, &sregs, X86_CR4_PCIDE);
test_cr4_feature_bit(vm, &sregs, X86_CR4_OSXSAVE);
test_cr4_feature_bit(vm, &sregs, X86_CR4_SMEP);
test_cr4_feature_bit(vm, &sregs, X86_CR4_SMAP);
test_cr4_feature_bit(vm, &sregs, X86_CR4_PKE);
/* Create a "real" VM and verify APIC_BASE can be set. */
vm = vm_create_default(VCPU_ID, 0, NULL);
vcpu_sregs_get(vm, VCPU_ID, &sregs);
sregs.apic_base = 1 << 10;
rc = _vcpu_sregs_set(vm, VCPU_ID, &sregs);
TEST_ASSERT(rc, "Set IA32_APIC_BASE to %llx (invalid)",
sregs.apic_base = 1 << 11;
rc = _vcpu_sregs_set(vm, VCPU_ID, &sregs);
TEST_ASSERT(!rc, "Couldn't set IA32_APIC_BASE to %llx (valid)",
return 0;