1 /*
2 * Copyright (C) 2023 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "gtest/gtest.h"
18
19 #include "berberis/backend/x86_64/local_guest_context_optimizer.h"
20
21 #include "berberis/backend/x86_64/machine_ir.h"
22 #include "berberis/backend/x86_64/machine_ir_builder.h"
23 #include "berberis/backend/x86_64/machine_ir_check.h"
24 #include "berberis/base/arena_alloc.h"
25 #include "berberis/guest_state/guest_addr.h"
26 #include "berberis/guest_state/guest_state.h"
27
28 namespace berberis {
29
30 namespace {
31
TEST(MachineIRLocalGuestContextOptimizer,RemoveReadAfterWrite)32 TEST(MachineIRLocalGuestContextOptimizer, RemoveReadAfterWrite) {
33 Arena arena;
34 x86_64::MachineIR machine_ir(&arena);
35
36 x86_64::MachineIRBuilder builder(&machine_ir);
37
38 auto bb = machine_ir.NewBasicBlock();
39 builder.StartBasicBlock(bb);
40 auto reg1 = machine_ir.AllocVReg();
41 auto reg2 = machine_ir.AllocVReg();
42 builder.GenPut(GetThreadStateRegOffset(0), reg1);
43 builder.GenGet(reg2, GetThreadStateRegOffset(0));
44 builder.Gen<PseudoJump>(kNullGuestAddr);
45
46 x86_64::RemoveLocalGuestContextAccesses(&machine_ir);
47 ASSERT_EQ(x86_64::CheckMachineIR(machine_ir), x86_64::kMachineIRCheckSuccess);
48
49 ASSERT_EQ(bb->insn_list().size(), 3UL);
50
51 auto* store_insn = *bb->insn_list().begin();
52 ASSERT_EQ(store_insn->opcode(), kMachineOpMovqMemBaseDispReg);
53 auto disp = x86_64::AsMachineInsnX86_64(store_insn)->disp();
54 ASSERT_EQ(disp, berberis::GetThreadStateRegOffset(0));
55 auto replaced_reg = store_insn->RegAt(1);
56 ASSERT_EQ(store_insn->RegAt(0), x86_64::kMachineRegRBP);
57
58 auto* load_copy_insn = *std::next(bb->insn_list().begin());
59 ASSERT_EQ(load_copy_insn->opcode(), kMachineOpPseudoCopy);
60 ASSERT_EQ(load_copy_insn->RegAt(0), reg2);
61 ASSERT_EQ(load_copy_insn->RegAt(1), replaced_reg);
62 }
63
TEST(MachineIRLocalGuestContextOptimizer,RemoveReadAfterRead)64 TEST(MachineIRLocalGuestContextOptimizer, RemoveReadAfterRead) {
65 Arena arena;
66 x86_64::MachineIR machine_ir(&arena);
67
68 x86_64::MachineIRBuilder builder(&machine_ir);
69
70 auto bb = machine_ir.NewBasicBlock();
71 builder.StartBasicBlock(bb);
72 auto reg1 = machine_ir.AllocVReg();
73 auto reg2 = machine_ir.AllocVReg();
74 builder.GenGet(reg1, GetThreadStateRegOffset(0));
75 builder.GenGet(reg2, GetThreadStateRegOffset(0));
76 builder.Gen<PseudoJump>(kNullGuestAddr);
77
78 x86_64::RemoveLocalGuestContextAccesses(&machine_ir);
79 ASSERT_EQ(x86_64::CheckMachineIR(machine_ir), x86_64::kMachineIRCheckSuccess);
80
81 ASSERT_EQ(bb->insn_list().size(), 3UL);
82 auto* load_insn = *bb->insn_list().begin();
83 ASSERT_EQ(load_insn->opcode(), kMachineOpMovqRegMemBaseDisp);
84 ASSERT_EQ(x86_64::AsMachineInsnX86_64(load_insn)->disp(), berberis::GetThreadStateRegOffset(0));
85 ASSERT_EQ(load_insn->RegAt(0), reg1);
86 ASSERT_EQ(load_insn->RegAt(1), x86_64::kMachineRegRBP);
87
88 auto* copy_insn = *std::next(bb->insn_list().begin());
89 ASSERT_EQ(copy_insn->opcode(), kMachineOpPseudoCopy);
90 ASSERT_EQ(copy_insn->RegAt(0), reg2);
91 ASSERT_EQ(copy_insn->RegAt(1), reg1);
92 }
93
TEST(MachineIRLocalGuestContextOptimizer,RemoveWriteAfterWrite)94 TEST(MachineIRLocalGuestContextOptimizer, RemoveWriteAfterWrite) {
95 Arena arena;
96 x86_64::MachineIR machine_ir(&arena);
97
98 x86_64::MachineIRBuilder builder(&machine_ir);
99
100 auto bb = machine_ir.NewBasicBlock();
101 builder.StartBasicBlock(bb);
102 auto reg1 = machine_ir.AllocVReg();
103 auto reg2 = machine_ir.AllocVReg();
104 builder.GenPut(GetThreadStateRegOffset(0), reg1);
105 builder.GenPut(GetThreadStateRegOffset(0), reg2);
106 builder.Gen<PseudoJump>(kNullGuestAddr);
107
108 x86_64::RemoveLocalGuestContextAccesses(&machine_ir);
109 ASSERT_EQ(x86_64::CheckMachineIR(machine_ir), x86_64::kMachineIRCheckSuccess);
110
111 ASSERT_EQ(bb->insn_list().size(), 2UL);
112 auto* store_insn = *bb->insn_list().begin();
113 ASSERT_EQ(store_insn->opcode(), kMachineOpMovqMemBaseDispReg);
114 ASSERT_EQ(x86_64::AsMachineInsnX86_64(store_insn)->disp(), berberis::GetThreadStateRegOffset(0));
115 ASSERT_EQ(store_insn->RegAt(1), reg2);
116 ASSERT_EQ(store_insn->RegAt(0), x86_64::kMachineRegRBP);
117 }
118
TEST(MachineIRLocalGuestContextOptimizer,DoNotRemoveAccessToMonitorValue)119 TEST(MachineIRLocalGuestContextOptimizer, DoNotRemoveAccessToMonitorValue) {
120 Arena arena;
121 x86_64::MachineIR machine_ir(&arena);
122
123 x86_64::MachineIRBuilder builder(&machine_ir);
124
125 auto bb = machine_ir.NewBasicBlock();
126 builder.StartBasicBlock(bb);
127 auto reg1 = machine_ir.AllocVReg();
128 auto reg2 = machine_ir.AllocVReg();
129 auto offset = offsetof(ProcessState, cpu.reservation_value);
130 builder.Gen<x86_64::MovqMemBaseDispReg>(x86_64::kMachineRegRBP, offset, reg1);
131 builder.Gen<x86_64::MovqMemBaseDispReg>(x86_64::kMachineRegRBP, offset, reg2);
132 builder.Gen<PseudoJump>(kNullGuestAddr);
133
134 x86_64::RemoveLocalGuestContextAccesses(&machine_ir);
135 ASSERT_EQ(x86_64::CheckMachineIR(machine_ir), x86_64::kMachineIRCheckSuccess);
136
137 ASSERT_EQ(bb->insn_list().size(), 3UL);
138 auto* store_insn_1 = *bb->insn_list().begin();
139 ASSERT_EQ(store_insn_1->opcode(), kMachineOpMovqMemBaseDispReg);
140 ASSERT_EQ(x86_64::AsMachineInsnX86_64(store_insn_1)->disp(), offset);
141
142 auto* store_insn_2 = *std::next(bb->insn_list().begin());
143 ASSERT_EQ(store_insn_2->opcode(), kMachineOpMovqMemBaseDispReg);
144 ASSERT_EQ(x86_64::AsMachineInsnX86_64(store_insn_2)->disp(), offset);
145 }
146
147 } // namespace
148
149 } // namespace berberis
150