130 lines · c
1// SPDX-License-Identifier: GPL-2.02#include <fcntl.h>3#include <stdio.h>4#include <stdlib.h>5#include <string.h>6#include <sys/ioctl.h>7 8#include "kvm_util.h"9#include "processor.h"10 11#define CPUID_MWAIT (1u << 3)12 13enum monitor_mwait_testcases {14 MWAIT_QUIRK_DISABLED = BIT(0),15 MISC_ENABLES_QUIRK_DISABLED = BIT(1),16 MWAIT_DISABLED = BIT(2),17};18 19/*20 * If both MWAIT and its quirk are disabled, MONITOR/MWAIT should #UD, in all21 * other scenarios KVM should emulate them as nops.22 */23#define GUEST_ASSERT_MONITOR_MWAIT(insn, testcase, vector) \24do { \25 bool fault_wanted = ((testcase) & MWAIT_QUIRK_DISABLED) && \26 ((testcase) & MWAIT_DISABLED); \27 \28 if (fault_wanted) \29 __GUEST_ASSERT((vector) == UD_VECTOR, \30 "Expected #UD on " insn " for testcase '0x%x', got '0x%x'", \31 testcase, vector); \32 else \33 __GUEST_ASSERT(!(vector), \34 "Expected success on " insn " for testcase '0x%x', got '0x%x'", \35 testcase, vector); \36} while (0)37 38static void guest_monitor_wait(int testcase)39{40 u8 vector;41 42 GUEST_SYNC(testcase);43 44 /*45 * Arbitrarily MONITOR this function, SVM performs fault checks before46 * intercept checks, so the inputs for MONITOR and MWAIT must be valid.47 */48 vector = kvm_asm_safe("monitor", "a"(guest_monitor_wait), "c"(0), "d"(0));49 GUEST_ASSERT_MONITOR_MWAIT("MONITOR", testcase, vector);50 51 vector = kvm_asm_safe("mwait", "a"(guest_monitor_wait), "c"(0), "d"(0));52 GUEST_ASSERT_MONITOR_MWAIT("MWAIT", testcase, vector);53}54 55static void guest_code(void)56{57 guest_monitor_wait(MWAIT_DISABLED);58 59 guest_monitor_wait(MWAIT_QUIRK_DISABLED | MWAIT_DISABLED);60 61 guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED | MWAIT_DISABLED);62 guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED);63 64 guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED | MWAIT_QUIRK_DISABLED | MWAIT_DISABLED);65 guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED | MWAIT_QUIRK_DISABLED);66 67 GUEST_DONE();68}69 70int main(int argc, char *argv[])71{72 uint64_t disabled_quirks;73 struct kvm_vcpu *vcpu;74 struct kvm_vm *vm;75 struct ucall uc;76 int testcase;77 78 TEST_REQUIRE(this_cpu_has(X86_FEATURE_MWAIT));79 TEST_REQUIRE(kvm_has_cap(KVM_CAP_DISABLE_QUIRKS2));80 81 vm = vm_create_with_one_vcpu(&vcpu, guest_code);82 vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_MWAIT);83 84 while (1) {85 vcpu_run(vcpu);86 TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);87 88 switch (get_ucall(vcpu, &uc)) {89 case UCALL_SYNC:90 testcase = uc.args[1];91 break;92 case UCALL_ABORT:93 REPORT_GUEST_ASSERT(uc);94 goto done;95 case UCALL_DONE:96 goto done;97 default:98 TEST_FAIL("Unknown ucall %lu", uc.cmd);99 goto done;100 }101 102 disabled_quirks = 0;103 if (testcase & MWAIT_QUIRK_DISABLED)104 disabled_quirks |= KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS;105 if (testcase & MISC_ENABLES_QUIRK_DISABLED)106 disabled_quirks |= KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT;107 vm_enable_cap(vm, KVM_CAP_DISABLE_QUIRKS2, disabled_quirks);108 109 /*110 * If the MISC_ENABLES quirk (KVM neglects to update CPUID to111 * enable/disable MWAIT) is disabled, toggle the ENABLE_MWAIT112 * bit in MISC_ENABLES accordingly. If the quirk is enabled,113 * the only valid configuration is MWAIT disabled, as CPUID114 * can't be manually changed after running the vCPU.115 */116 if (!(testcase & MISC_ENABLES_QUIRK_DISABLED)) {117 TEST_ASSERT(testcase & MWAIT_DISABLED,118 "Can't toggle CPUID features after running vCPU");119 continue;120 }121 122 vcpu_set_msr(vcpu, MSR_IA32_MISC_ENABLE,123 (testcase & MWAIT_DISABLED) ? 0 : MSR_IA32_MISC_ENABLE_MWAIT);124 }125 126done:127 kvm_vm_free(vm);128 return 0;129}130