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 #include <fcntl.h> 14 #include <stdio.h> 15 #include <stdlib.h> 16 #include <string.h> 17 #include <sys/ioctl.h> 18 19 #include "test_util.h" 20 21 #include "kvm_util.h" 22 #include "processor.h" 23 24 #define TEST_INVALID_CR_BIT(vcpu, cr, orig, bit) \ 25 do { \ 26 struct kvm_sregs new; \ 27 int rc; \ 28 \ 29 /* Skip the sub-test, the feature/bit is supported. */ \ 30 if (orig.cr & bit) \ 31 break; \ 32 \ 33 memcpy(&new, &orig, sizeof(sregs)); \ 34 new.cr |= bit; \ 35 \ 36 rc = _vcpu_sregs_set(vcpu, &new); \ 37 TEST_ASSERT(rc, "KVM allowed invalid " #cr " bit (0x%lx)", bit); \ 38 \ 39 /* Sanity check that KVM didn't change anything. */ \ 40 vcpu_sregs_get(vcpu, &new); \ 41 TEST_ASSERT(!memcmp(&new, &orig, sizeof(new)), "KVM modified sregs"); \ 42 } while (0) 43 44 #define KVM_ALWAYS_ALLOWED_CR4 (X86_CR4_VME | X86_CR4_PVI | X86_CR4_TSD | \ 45 X86_CR4_DE | X86_CR4_PSE | X86_CR4_PAE | \ 46 X86_CR4_MCE | X86_CR4_PGE | X86_CR4_PCE | \ 47 X86_CR4_OSFXSR | X86_CR4_OSXMMEXCPT) 48 49 static uint64_t calc_supported_cr4_feature_bits(void) 50 { 51 uint64_t cr4 = KVM_ALWAYS_ALLOWED_CR4; 52 53 if (kvm_cpu_has(X86_FEATURE_UMIP)) 54 cr4 |= X86_CR4_UMIP; 55 if (kvm_cpu_has(X86_FEATURE_LA57)) 56 cr4 |= X86_CR4_LA57; 57 if (kvm_cpu_has(X86_FEATURE_VMX)) 58 cr4 |= X86_CR4_VMXE; 59 if (kvm_cpu_has(X86_FEATURE_SMX)) 60 cr4 |= X86_CR4_SMXE; 61 if (kvm_cpu_has(X86_FEATURE_FSGSBASE)) 62 cr4 |= X86_CR4_FSGSBASE; 63 if (kvm_cpu_has(X86_FEATURE_PCID)) 64 cr4 |= X86_CR4_PCIDE; 65 if (kvm_cpu_has(X86_FEATURE_XSAVE)) 66 cr4 |= X86_CR4_OSXSAVE; 67 if (kvm_cpu_has(X86_FEATURE_SMEP)) 68 cr4 |= X86_CR4_SMEP; 69 if (kvm_cpu_has(X86_FEATURE_SMAP)) 70 cr4 |= X86_CR4_SMAP; 71 if (kvm_cpu_has(X86_FEATURE_PKU)) 72 cr4 |= X86_CR4_PKE; 73 74 return cr4; 75 } 76 77 static void test_cr_bits(struct kvm_vcpu *vcpu, uint64_t cr4) 78 { 79 struct kvm_sregs sregs; 80 int rc, i; 81 82 vcpu_sregs_get(vcpu, &sregs); 83 sregs.cr0 &= ~(X86_CR0_CD | X86_CR0_NW); 84 sregs.cr4 |= cr4; 85 rc = _vcpu_sregs_set(vcpu, &sregs); 86 TEST_ASSERT(!rc, "Failed to set supported CR4 bits (0x%lx)", cr4); 87 88 TEST_ASSERT(!!(sregs.cr4 & X86_CR4_OSXSAVE) == 89 (vcpu->cpuid && vcpu_cpuid_has(vcpu, X86_FEATURE_OSXSAVE)), 90 "KVM didn't %s OSXSAVE in CPUID as expected", 91 (sregs.cr4 & X86_CR4_OSXSAVE) ? "set" : "clear"); 92 93 TEST_ASSERT(!!(sregs.cr4 & X86_CR4_PKE) == 94 (vcpu->cpuid && vcpu_cpuid_has(vcpu, X86_FEATURE_OSPKE)), 95 "KVM didn't %s OSPKE in CPUID as expected", 96 (sregs.cr4 & X86_CR4_PKE) ? "set" : "clear"); 97 98 vcpu_sregs_get(vcpu, &sregs); 99 TEST_ASSERT(sregs.cr4 == cr4, "sregs.CR4 (0x%llx) != CR4 (0x%lx)", 100 sregs.cr4, cr4); 101 102 TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_UMIP); 103 TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_LA57); 104 TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_VMXE); 105 TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_SMXE); 106 TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_FSGSBASE); 107 TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_PCIDE); 108 TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_OSXSAVE); 109 TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_SMEP); 110 TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_SMAP); 111 TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_PKE); 112 113 for (i = 32; i < 64; i++) 114 TEST_INVALID_CR_BIT(vcpu, cr0, sregs, BIT(i)); 115 116 /* NW without CD is illegal, as is PG without PE. */ 117 TEST_INVALID_CR_BIT(vcpu, cr0, sregs, X86_CR0_NW); 118 TEST_INVALID_CR_BIT(vcpu, cr0, sregs, X86_CR0_PG); 119 } 120 121 int main(int argc, char *argv[]) 122 { 123 struct kvm_sregs sregs; 124 struct kvm_vcpu *vcpu; 125 struct kvm_vm *vm; 126 int rc; 127 128 /* 129 * Create a dummy VM, specifically to avoid doing KVM_SET_CPUID2, and 130 * use it to verify KVM enforces guest CPUID even if *userspace* never 131 * sets CPUID. 132 */ 133 vm = vm_create_barebones(); 134 vcpu = __vm_vcpu_add(vm, 0); 135 test_cr_bits(vcpu, KVM_ALWAYS_ALLOWED_CR4); 136 kvm_vm_free(vm); 137 138 /* Create a "real" VM with a fully populated guest CPUID and verify 139 * APIC_BASE and all supported CR4 can be set. 140 */ 141 vm = vm_create_with_one_vcpu(&vcpu, NULL); 142 143 vcpu_sregs_get(vcpu, &sregs); 144 sregs.apic_base = 1 << 10; 145 rc = _vcpu_sregs_set(vcpu, &sregs); 146 TEST_ASSERT(rc, "Set IA32_APIC_BASE to %llx (invalid)", 147 sregs.apic_base); 148 sregs.apic_base = 1 << 11; 149 rc = _vcpu_sregs_set(vcpu, &sregs); 150 TEST_ASSERT(!rc, "Couldn't set IA32_APIC_BASE to %llx (valid)", 151 sregs.apic_base); 152 153 test_cr_bits(vcpu, calc_supported_cr4_feature_bits()); 154 155 kvm_vm_free(vm); 156 157 return 0; 158 } 159