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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * vmx_tsc_adjust_test4 *5 * Copyright (C) 2018, Google LLC.6 *7 * IA32_TSC_ADJUST test8 *9 * According to the SDM, "if an execution of WRMSR to the10 * IA32_TIME_STAMP_COUNTER MSR adds (or subtracts) value X from the TSC,11 * the logical processor also adds (or subtracts) value X from the12 * IA32_TSC_ADJUST MSR.13 *14 * Note that when L1 doesn't intercept writes to IA32_TSC, a15 * WRMSR(IA32_TSC) from L2 sets L1's TSC value, not L2's perceived TSC16 * value.17 *18 * This test verifies that this unusual case is handled correctly.19 */20 21#include "test_util.h"22#include "kvm_util.h"23#include "processor.h"24#include "vmx.h"25 26#include <string.h>27#include <sys/ioctl.h>28 29#include "kselftest.h"30 31#ifndef MSR_IA32_TSC_ADJUST32#define MSR_IA32_TSC_ADJUST 0x3b33#endif34 35#define TSC_ADJUST_VALUE (1ll << 32)36#define TSC_OFFSET_VALUE -(1ll << 48)37 38enum {39 PORT_ABORT = 0x1000,40 PORT_REPORT,41 PORT_DONE,42};43 44enum {45 VMXON_PAGE = 0,46 VMCS_PAGE,47 MSR_BITMAP_PAGE,48 49 NUM_VMX_PAGES,50};51 52/* The virtual machine object. */53static struct kvm_vm *vm;54 55static void check_ia32_tsc_adjust(int64_t max)56{57 int64_t adjust;58 59 adjust = rdmsr(MSR_IA32_TSC_ADJUST);60 GUEST_SYNC(adjust);61 GUEST_ASSERT(adjust <= max);62}63 64static void l2_guest_code(void)65{66 uint64_t l1_tsc = rdtsc() - TSC_OFFSET_VALUE;67 68 wrmsr(MSR_IA32_TSC, l1_tsc - TSC_ADJUST_VALUE);69 check_ia32_tsc_adjust(-2 * TSC_ADJUST_VALUE);70 71 /* Exit to L1 */72 __asm__ __volatile__("vmcall");73}74 75static void l1_guest_code(struct vmx_pages *vmx_pages)76{77#define L2_GUEST_STACK_SIZE 6478 unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];79 uint32_t control;80 uintptr_t save_cr3;81 82 GUEST_ASSERT(rdtsc() < TSC_ADJUST_VALUE);83 wrmsr(MSR_IA32_TSC, rdtsc() - TSC_ADJUST_VALUE);84 check_ia32_tsc_adjust(-1 * TSC_ADJUST_VALUE);85 86 GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));87 GUEST_ASSERT(load_vmcs(vmx_pages));88 89 /* Prepare the VMCS for L2 execution. */90 prepare_vmcs(vmx_pages, l2_guest_code,91 &l2_guest_stack[L2_GUEST_STACK_SIZE]);92 control = vmreadz(CPU_BASED_VM_EXEC_CONTROL);93 control |= CPU_BASED_USE_MSR_BITMAPS | CPU_BASED_USE_TSC_OFFSETTING;94 vmwrite(CPU_BASED_VM_EXEC_CONTROL, control);95 vmwrite(TSC_OFFSET, TSC_OFFSET_VALUE);96 97 /* Jump into L2. First, test failure to load guest CR3. */98 save_cr3 = vmreadz(GUEST_CR3);99 vmwrite(GUEST_CR3, -1ull);100 GUEST_ASSERT(!vmlaunch());101 GUEST_ASSERT(vmreadz(VM_EXIT_REASON) ==102 (EXIT_REASON_FAILED_VMENTRY | EXIT_REASON_INVALID_STATE));103 check_ia32_tsc_adjust(-1 * TSC_ADJUST_VALUE);104 vmwrite(GUEST_CR3, save_cr3);105 106 GUEST_ASSERT(!vmlaunch());107 GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);108 109 check_ia32_tsc_adjust(-2 * TSC_ADJUST_VALUE);110 111 GUEST_DONE();112}113 114static void report(int64_t val)115{116 pr_info("IA32_TSC_ADJUST is %ld (%lld * TSC_ADJUST_VALUE + %lld).\n",117 val, val / TSC_ADJUST_VALUE, val % TSC_ADJUST_VALUE);118}119 120int main(int argc, char *argv[])121{122 vm_vaddr_t vmx_pages_gva;123 struct kvm_vcpu *vcpu;124 125 TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));126 127 vm = vm_create_with_one_vcpu(&vcpu, (void *) l1_guest_code);128 129 /* Allocate VMX pages and shared descriptors (vmx_pages). */130 vcpu_alloc_vmx(vm, &vmx_pages_gva);131 vcpu_args_set(vcpu, 1, vmx_pages_gva);132 133 for (;;) {134 struct ucall uc;135 136 vcpu_run(vcpu);137 TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);138 139 switch (get_ucall(vcpu, &uc)) {140 case UCALL_ABORT:141 REPORT_GUEST_ASSERT(uc);142 /* NOT REACHED */143 case UCALL_SYNC:144 report(uc.args[1]);145 break;146 case UCALL_DONE:147 goto done;148 default:149 TEST_FAIL("Unknown ucall %lu", uc.cmd);150 }151 }152 153done:154 kvm_vm_free(vm);155 return 0;156}157