diff options
| -rw-r--r-- | tools/testing/selftests/kvm/Makefile.kvm | 1 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/x86/evmcs_smm_controls_test.c | 150 |
2 files changed, 151 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index fdec90e85467..dc68371f76a3 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -71,6 +71,7 @@ TEST_GEN_PROGS_x86 += x86/cpuid_test TEST_GEN_PROGS_x86 += x86/cr4_cpuid_sync_test TEST_GEN_PROGS_x86 += x86/dirty_log_page_splitting_test TEST_GEN_PROGS_x86 += x86/feature_msrs_test +TEST_GEN_PROGS_x86 += x86/evmcs_smm_controls_test TEST_GEN_PROGS_x86 += x86/exit_on_emulation_failure_test TEST_GEN_PROGS_x86 += x86/fastops_test TEST_GEN_PROGS_x86 += x86/fix_hypercall_test diff --git a/tools/testing/selftests/kvm/x86/evmcs_smm_controls_test.c b/tools/testing/selftests/kvm/x86/evmcs_smm_controls_test.c new file mode 100644 index 000000000000..af7c90103396 --- /dev/null +++ b/tools/testing/selftests/kvm/x86/evmcs_smm_controls_test.c @@ -0,0 +1,150 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2026, Red Hat, Inc. + * + * Test that vmx_leave_smm() validates vmcs12 controls before re-entering + * nested guest mode on RSM. + */ +#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 "smm.h" +#include "hyperv.h" +#include "vmx.h" + +#define SMRAM_GPA 0x1000000 +#define SMRAM_STAGE 0xfe + +#define SYNC_PORT 0xe + +#define STR(x) #x +#define XSTR(s) STR(s) + +/* + * SMI handler: runs in real-address mode. + * Reports SMRAM_STAGE via port IO, then does RSM. + */ +static uint8_t smi_handler[] = { + 0xb0, SMRAM_STAGE, /* mov $SMRAM_STAGE, %al */ + 0xe4, SYNC_PORT, /* in $SYNC_PORT, %al */ + 0x0f, 0xaa, /* rsm */ +}; + +static inline void sync_with_host(uint64_t phase) +{ + asm volatile("in $" XSTR(SYNC_PORT) ", %%al \n" + : "+a" (phase)); +} + +static void l2_guest_code(void) +{ + sync_with_host(1); + + /* After SMI+RSM with invalid controls, we should not reach here. */ + vmcall(); +} + +static void guest_code(struct vmx_pages *vmx_pages, + struct hyperv_test_pages *hv_pages) +{ +#define L2_GUEST_STACK_SIZE 64 + unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; + + /* Set up Hyper-V enlightenments and eVMCS */ + wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID); + enable_vp_assist(hv_pages->vp_assist_gpa, hv_pages->vp_assist); + evmcs_enable(); + + GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages)); + GUEST_ASSERT(load_evmcs(hv_pages)); + prepare_vmcs(vmx_pages, l2_guest_code, + &l2_guest_stack[L2_GUEST_STACK_SIZE]); + + GUEST_ASSERT(!vmlaunch()); + + /* L2 exits via vmcall if test fails */ + sync_with_host(2); +} + +int main(int argc, char *argv[]) +{ + vm_vaddr_t vmx_pages_gva = 0, hv_pages_gva = 0; + struct hyperv_test_pages *hv; + struct hv_enlightened_vmcs *evmcs; + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + struct kvm_regs regs; + int stage_reported; + + TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX)); + TEST_REQUIRE(kvm_has_cap(KVM_CAP_NESTED_STATE)); + TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS)); + TEST_REQUIRE(kvm_has_cap(KVM_CAP_X86_SMM)); + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + + setup_smram(vm, vcpu, SMRAM_GPA, smi_handler, sizeof(smi_handler)); + + vcpu_set_hv_cpuid(vcpu); + vcpu_enable_evmcs(vcpu); + vcpu_alloc_vmx(vm, &vmx_pages_gva); + hv = vcpu_alloc_hyperv_test_pages(vm, &hv_pages_gva); + vcpu_args_set(vcpu, 2, vmx_pages_gva, hv_pages_gva); + + vcpu_run(vcpu); + + /* L2 is running and syncs with host. */ + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO); + vcpu_regs_get(vcpu, ®s); + stage_reported = regs.rax & 0xff; + TEST_ASSERT(stage_reported == 1, + "Expected stage 1, got %d", stage_reported); + + /* Inject SMI while L2 is running. */ + inject_smi(vcpu); + vcpu_run(vcpu); + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO); + vcpu_regs_get(vcpu, ®s); + stage_reported = regs.rax & 0xff; + TEST_ASSERT(stage_reported == SMRAM_STAGE, + "Expected SMM handler stage %#x, got %#x", + SMRAM_STAGE, stage_reported); + + /* + * Guest is now paused in the SMI handler, about to execute RSM. + * Hack the eVMCS page to set-up invalid pin-based execution + * control (PIN_BASED_VIRTUAL_NMIS without PIN_BASED_NMI_EXITING). + */ + evmcs = hv->enlightened_vmcs_hva; + evmcs->pin_based_vm_exec_control |= PIN_BASED_VIRTUAL_NMIS; + evmcs->hv_clean_fields = 0; + + /* + * Trigger copy_enlightened_to_vmcs12() via KVM_GET_NESTED_STATE, + * copying the invalid pin_based_vm_exec_control into cached_vmcs12. + */ + union { + struct kvm_nested_state state; + char state_[16384]; + } nested_state_buf; + + memset(&nested_state_buf, 0, sizeof(nested_state_buf)); + nested_state_buf.state.size = sizeof(nested_state_buf); + vcpu_nested_state_get(vcpu, &nested_state_buf.state); + + /* + * Resume the guest. The SMI handler executes RSM, which calls + * vmx_leave_smm(). nested_vmx_check_controls() should detect + * VIRTUAL_NMIS without NMI_EXITING and cause a triple fault. + */ + vcpu_run(vcpu); + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_SHUTDOWN); + + kvm_vm_free(vm); + return 0; +} |