diff options
Diffstat (limited to 'tools/testing/selftests/kvm/x86_64/set_sregs_test.c')
-rw-r--r-- | tools/testing/selftests/kvm/x86_64/set_sregs_test.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/set_sregs_test.c b/tools/testing/selftests/kvm/x86_64/set_sregs_test.c new file mode 100644 index 000000000..2bb08bf21 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/set_sregs_test.c @@ -0,0 +1,137 @@ +// 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. + */ +#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" + +static void test_cr4_feature_bit(struct kvm_vcpu *vcpu, 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) + return; + + memcpy(&sregs, orig, sizeof(sregs)); + sregs.cr4 |= feature_bit; + + rc = _vcpu_sregs_set(vcpu, &sregs); + TEST_ASSERT(rc, "KVM allowed unsupported CR4 bit (0x%lx)", feature_bit); + + /* Sanity check that KVM didn't change anything. */ + vcpu_sregs_get(vcpu, &sregs); + TEST_ASSERT(!memcmp(&sregs, orig, sizeof(sregs)), "KVM modified sregs"); +} + +static uint64_t calc_supported_cr4_feature_bits(void) +{ + uint64_t cr4; + + 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; + 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; +} + +int main(int argc, char *argv[]) +{ + struct kvm_sregs sregs; + struct kvm_vcpu *vcpu; + 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 = vm_create_barebones(); + vcpu = __vm_vcpu_add(vm, 0); + + vcpu_sregs_get(vcpu, &sregs); + + sregs.cr4 |= calc_supported_cr4_feature_bits(); + cr4 = sregs.cr4; + + rc = _vcpu_sregs_set(vcpu, &sregs); + TEST_ASSERT(!rc, "Failed to set supported CR4 bits (0x%lx)", cr4); + + vcpu_sregs_get(vcpu, &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(vcpu, &sregs, X86_CR4_UMIP); + test_cr4_feature_bit(vcpu, &sregs, X86_CR4_LA57); + test_cr4_feature_bit(vcpu, &sregs, X86_CR4_VMXE); + test_cr4_feature_bit(vcpu, &sregs, X86_CR4_SMXE); + test_cr4_feature_bit(vcpu, &sregs, X86_CR4_FSGSBASE); + test_cr4_feature_bit(vcpu, &sregs, X86_CR4_PCIDE); + test_cr4_feature_bit(vcpu, &sregs, X86_CR4_OSXSAVE); + test_cr4_feature_bit(vcpu, &sregs, X86_CR4_SMEP); + test_cr4_feature_bit(vcpu, &sregs, X86_CR4_SMAP); + test_cr4_feature_bit(vcpu, &sregs, X86_CR4_PKE); + kvm_vm_free(vm); + + /* Create a "real" VM and verify APIC_BASE 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); + + kvm_vm_free(vm); + + return 0; +} |