1 // SPDX-License-Identifier: GPL-2.0 2 #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 13 enum monitor_mwait_testcases { 14 MWAIT_QUIRK_DISABLED = BIT(0), 15 MISC_ENABLES_QUIRK_DISABLED = BIT(1), 16 MWAIT_DISABLED = BIT(2), 17 }; 18 19 static void guest_monitor_wait(int testcase) 20 { 21 /* 22 * If both MWAIT and its quirk are disabled, MONITOR/MWAIT should #UD, 23 * in all other scenarios KVM should emulate them as nops. 24 */ 25 bool fault_wanted = (testcase & MWAIT_QUIRK_DISABLED) && 26 (testcase & MWAIT_DISABLED); 27 u8 vector; 28 29 GUEST_SYNC(testcase); 30 31 /* 32 * Arbitrarily MONITOR this function, SVM performs fault checks before 33 * intercept checks, so the inputs for MONITOR and MWAIT must be valid. 34 */ 35 vector = kvm_asm_safe("monitor", "a"(guest_monitor_wait), "c"(0), "d"(0)); 36 if (fault_wanted) 37 GUEST_ASSERT_2(vector == UD_VECTOR, testcase, vector); 38 else 39 GUEST_ASSERT_2(!vector, testcase, vector); 40 41 vector = kvm_asm_safe("mwait", "a"(guest_monitor_wait), "c"(0), "d"(0)); 42 if (fault_wanted) 43 GUEST_ASSERT_2(vector == UD_VECTOR, testcase, vector); 44 else 45 GUEST_ASSERT_2(!vector, testcase, vector); 46 } 47 48 static void guest_code(void) 49 { 50 guest_monitor_wait(MWAIT_DISABLED); 51 52 guest_monitor_wait(MWAIT_QUIRK_DISABLED | MWAIT_DISABLED); 53 54 guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED | MWAIT_DISABLED); 55 guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED); 56 57 guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED | MWAIT_QUIRK_DISABLED | MWAIT_DISABLED); 58 guest_monitor_wait(MISC_ENABLES_QUIRK_DISABLED | MWAIT_QUIRK_DISABLED); 59 60 GUEST_DONE(); 61 } 62 63 int main(int argc, char *argv[]) 64 { 65 uint64_t disabled_quirks; 66 struct kvm_vcpu *vcpu; 67 struct kvm_run *run; 68 struct kvm_vm *vm; 69 struct ucall uc; 70 int testcase; 71 72 TEST_REQUIRE(kvm_has_cap(KVM_CAP_DISABLE_QUIRKS2)); 73 74 vm = vm_create_with_one_vcpu(&vcpu, guest_code); 75 vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_MWAIT); 76 77 run = vcpu->run; 78 79 vm_init_descriptor_tables(vm); 80 vcpu_init_descriptor_tables(vcpu); 81 82 while (1) { 83 vcpu_run(vcpu); 84 85 TEST_ASSERT(run->exit_reason == KVM_EXIT_IO, 86 "Unexpected exit reason: %u (%s),\n", 87 run->exit_reason, 88 exit_reason_str(run->exit_reason)); 89 90 switch (get_ucall(vcpu, &uc)) { 91 case UCALL_SYNC: 92 testcase = uc.args[1]; 93 break; 94 case UCALL_ABORT: 95 REPORT_GUEST_ASSERT_2(uc, "testcase = %lx, vector = %ld"); 96 goto done; 97 case UCALL_DONE: 98 goto done; 99 default: 100 TEST_FAIL("Unknown ucall %lu", uc.cmd); 101 goto done; 102 } 103 104 disabled_quirks = 0; 105 if (testcase & MWAIT_QUIRK_DISABLED) 106 disabled_quirks |= KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS; 107 if (testcase & MISC_ENABLES_QUIRK_DISABLED) 108 disabled_quirks |= KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT; 109 vm_enable_cap(vm, KVM_CAP_DISABLE_QUIRKS2, disabled_quirks); 110 111 /* 112 * If the MISC_ENABLES quirk (KVM neglects to update CPUID to 113 * enable/disable MWAIT) is disabled, toggle the ENABLE_MWAIT 114 * bit in MISC_ENABLES accordingly. If the quirk is enabled, 115 * the only valid configuration is MWAIT disabled, as CPUID 116 * can't be manually changed after running the vCPU. 117 */ 118 if (!(testcase & MISC_ENABLES_QUIRK_DISABLED)) { 119 TEST_ASSERT(testcase & MWAIT_DISABLED, 120 "Can't toggle CPUID features after running vCPU"); 121 continue; 122 } 123 124 vcpu_set_msr(vcpu, MSR_IA32_MISC_ENABLE, 125 (testcase & MWAIT_DISABLED) ? 0 : MSR_IA32_MISC_ENABLE_MWAIT); 126 } 127 128 done: 129 kvm_vm_free(vm); 130 return 0; 131 } 132