diff options
Diffstat (limited to 'tools/testing/selftests/kvm/x86/set_sregs_test.c')
| -rw-r--r-- | tools/testing/selftests/kvm/x86/set_sregs_test.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86/set_sregs_test.c b/tools/testing/selftests/kvm/x86/set_sregs_test.c new file mode 100644 index 000000000000..f4095a3d1278 --- /dev/null +++ b/tools/testing/selftests/kvm/x86/set_sregs_test.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * KVM_SET_SREGS tests + * + * 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. + */ +#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 TEST_INVALID_CR_BIT(vcpu, cr, orig, bit) \ +do { \ + struct kvm_sregs new; \ + int rc; \ + \ + /* Skip the sub-test, the feature/bit is supported. */ \ + if (orig.cr & bit) \ + break; \ + \ + memcpy(&new, &orig, sizeof(sregs)); \ + new.cr |= bit; \ + \ + rc = _vcpu_sregs_set(vcpu, &new); \ + TEST_ASSERT(rc, "KVM allowed invalid " #cr " bit (0x%lx)", bit); \ + \ + /* Sanity check that KVM didn't change anything. */ \ + vcpu_sregs_get(vcpu, &new); \ + TEST_ASSERT(!memcmp(&new, &orig, sizeof(new)), "KVM modified sregs"); \ +} while (0) + +#define KVM_ALWAYS_ALLOWED_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 | X86_CR4_PCE | \ + X86_CR4_OSFXSR | X86_CR4_OSXMMEXCPT) + +static uint64_t calc_supported_cr4_feature_bits(void) +{ + uint64_t cr4 = KVM_ALWAYS_ALLOWED_CR4; + + if (kvm_cpu_has(X86_FEATURE_UMIP)) + cr4 |= X86_CR4_UMIP; + if (kvm_cpu_has(X86_FEATURE_LA57)) + cr4 |= X86_CR4_LA57; + if (kvm_cpu_has(X86_FEATURE_VMX)) + cr4 |= X86_CR4_VMXE; + if (kvm_cpu_has(X86_FEATURE_SMX)) + cr4 |= X86_CR4_SMXE; + if (kvm_cpu_has(X86_FEATURE_FSGSBASE)) + cr4 |= X86_CR4_FSGSBASE; + if (kvm_cpu_has(X86_FEATURE_PCID)) + cr4 |= X86_CR4_PCIDE; + if (kvm_cpu_has(X86_FEATURE_XSAVE)) + cr4 |= X86_CR4_OSXSAVE; + if (kvm_cpu_has(X86_FEATURE_SMEP)) + cr4 |= X86_CR4_SMEP; + if (kvm_cpu_has(X86_FEATURE_SMAP)) + cr4 |= X86_CR4_SMAP; + if (kvm_cpu_has(X86_FEATURE_PKU)) + cr4 |= X86_CR4_PKE; + + return cr4; +} + +static void test_cr_bits(struct kvm_vcpu *vcpu, uint64_t cr4) +{ + struct kvm_sregs sregs; + int rc, i; + + vcpu_sregs_get(vcpu, &sregs); + sregs.cr0 &= ~(X86_CR0_CD | X86_CR0_NW); + sregs.cr4 |= cr4; + rc = _vcpu_sregs_set(vcpu, &sregs); + TEST_ASSERT(!rc, "Failed to set supported CR4 bits (0x%lx)", cr4); + + TEST_ASSERT(!!(sregs.cr4 & X86_CR4_OSXSAVE) == + (vcpu->cpuid && vcpu_cpuid_has(vcpu, X86_FEATURE_OSXSAVE)), + "KVM didn't %s OSXSAVE in CPUID as expected", + (sregs.cr4 & X86_CR4_OSXSAVE) ? "set" : "clear"); + + TEST_ASSERT(!!(sregs.cr4 & X86_CR4_PKE) == + (vcpu->cpuid && vcpu_cpuid_has(vcpu, X86_FEATURE_OSPKE)), + "KVM didn't %s OSPKE in CPUID as expected", + (sregs.cr4 & X86_CR4_PKE) ? "set" : "clear"); + + vcpu_sregs_get(vcpu, &sregs); + TEST_ASSERT(sregs.cr4 == cr4, "sregs.CR4 (0x%llx) != CR4 (0x%lx)", + sregs.cr4, cr4); + + TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_UMIP); + TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_LA57); + TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_VMXE); + TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_SMXE); + TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_FSGSBASE); + TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_PCIDE); + TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_OSXSAVE); + TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_SMEP); + TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_SMAP); + TEST_INVALID_CR_BIT(vcpu, cr4, sregs, X86_CR4_PKE); + + for (i = 32; i < 64; i++) + TEST_INVALID_CR_BIT(vcpu, cr0, sregs, BIT(i)); + + /* NW without CD is illegal, as is PG without PE. */ + TEST_INVALID_CR_BIT(vcpu, cr0, sregs, X86_CR0_NW); + TEST_INVALID_CR_BIT(vcpu, cr0, sregs, X86_CR0_PG); +} + +int main(int argc, char *argv[]) +{ + struct kvm_sregs sregs; + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + int rc; + + /* + * Create a dummy VM, specifically to avoid doing KVM_SET_CPUID2, and + * use it to verify KVM enforces guest CPUID even if *userspace* never + * sets CPUID. + */ + vm = vm_create_barebones(); + vcpu = __vm_vcpu_add(vm, 0); + test_cr_bits(vcpu, KVM_ALWAYS_ALLOWED_CR4); + kvm_vm_free(vm); + + /* Create a "real" VM with a fully populated guest CPUID and verify + * APIC_BASE and all supported CR4 can be set. + */ + vm = vm_create_with_one_vcpu(&vcpu, NULL); + + vcpu_sregs_get(vcpu, &sregs); + sregs.apic_base = 1 << 10; + rc = _vcpu_sregs_set(vcpu, &sregs); + TEST_ASSERT(rc, "Set IA32_APIC_BASE to %llx (invalid)", + sregs.apic_base); + sregs.apic_base = 1 << 11; + rc = _vcpu_sregs_set(vcpu, &sregs); + TEST_ASSERT(!rc, "Couldn't set IA32_APIC_BASE to %llx (valid)", + sregs.apic_base); + + test_cr_bits(vcpu, calc_supported_cr4_feature_bits()); + + kvm_vm_free(vm); + + return 0; +} |