Add tests for SDIV instructions (#153)

* Add tests for SDIV instructions Addresses part of #152 Signed-off-by: Dave Thaler <dthaler@microsoft.com> * Add cpu_version=v4 Signed-off-by: Dave Thaler <dthaler@microsoft.com> * Bug fix Signed-off-by: Dave Thaler <dthaler1968@gmail.com> * Fix test case Signed-off-by: Dave Thaler <dthaler1968@gmail.com> * Fix test Signed-off-by: Dave Thaler <dthaler1968@gmail.com> * Fix readme and error Signed-off-by: Dave Thaler <dthaler1968@gmail.com> * Remove v4 test on ubuntu Signed-off-by: Dave Thaler <dthaler1968@gmail.com> --------- Signed-off-by: Dave Thaler <dthaler@microsoft.com> Signed-off-by: Dave Thaler <dthaler1968@gmail.com>
Alan-Jowett · Jan 11, 2024 · 13de786 · 13de786
1 parent 4797052
commit 13de786
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Showing 13 changed files with 253 additions and 173 deletions.
diff --git a/README.md b/README.md
@@ -22,7 +22,7 @@ Linux Kernel is treated as the authorative eBPF implementation.
 ### Ubuntu
 
 ```
-sudo apt-get install -y libboost-dev libboost-filesystem-dev libboost-program-options-dev libelf-dev lcov
+sudo apt-get install -y libboost-dev libboost-filesystem-dev libboost-program-options-dev libelf-dev lcov libbpf-dev
 ```
 
 ### MacOS

diff --git a/include/bpf_conformance.h b/include/bpf_conformance.h
@@ -22,6 +22,7 @@ typedef enum class _bpf_conformance_test_cpu_version
     v1 = 1,
     v2 = 2,
     v3 = 3,
+    v4 = 4,
 } bpf_conformance_test_cpu_version_t;
 
 // Add typedef for backwards compatibility.

diff --git a/src/bpf_assembler.cc b/src/bpf_assembler.cc
@@ -45,6 +45,7 @@ typedef class _bpf_assembler
         {"sub", 0x1},
         {"mul", 0x2},
         {"div", 0x3},
+        {"sdiv", 0x3},
         {"or", 0x4},
         {"and", 0x5},
         {"lsh", 0x6},
@@ -245,6 +246,9 @@ typedef class _bpf_assembler
             inst.imm = _decode_imm32(mnemonic.substr(2));
             return inst;
         }
+        if (mnemonic.starts_with("sdiv")) {
+            inst.offset = 1;
+        }
 
         if (mnemonic.ends_with("32")) {
             inst.opcode |= EBPF_CLS_ALU;
@@ -444,6 +448,7 @@ typedef class _bpf_assembler
         {"be16", {&_bpf_assembler::_encode_alu, 1}},  {"be32", {&_bpf_assembler::_encode_alu, 1}},
         {"be64", {&_bpf_assembler::_encode_alu, 1}},  {"call", {&_bpf_assembler::_encode_jmp, 2}},
         {"div", {&_bpf_assembler::_encode_alu, 2}},   {"div32", {&_bpf_assembler::_encode_alu, 2}},
+        {"sdiv", {&_bpf_assembler::_encode_alu, 2}},  {"sdiv32", {&_bpf_assembler::_encode_alu, 2}},
         {"exit", {&_bpf_assembler::_encode_jmp, 0}},  {"ja", {&_bpf_assembler::_encode_jmp, 1}},
         {"jeq", {&_bpf_assembler::_encode_jmp, 3}},   {"jeq32", {&_bpf_assembler::_encode_jmp, 3}},
         {"jge", {&_bpf_assembler::_encode_jmp, 3}},   {"jge32", {&_bpf_assembler::_encode_jmp, 3}},

diff --git a/src/bpf_conformance.cc b/src/bpf_conformance.cc
@@ -130,6 +130,18 @@ _generate_xdp_prolog(size_t size)
     };
 }
 
+bpf_conformance_test_cpu_version_t
+get_instruction_cpu_version(ebpf_inst inst)
+{
+    auto instruction = std::find_if(instructions_from_spec.begin(), instructions_from_spec.end(), [&](const auto &instruction) {
+        return (instruction.opcode == inst.opcode) &&
+               (!needs_src(inst.opcode) || instruction.src == inst.src) &&
+               (!needs_imm(inst.opcode) || instruction.imm == inst.imm) &&
+               (!needs_offset(inst.opcode) || instruction.offset == inst.offset);
+         });
+    return instruction->cpu_version;
+}
+
 std::map<std::filesystem::path, std::tuple<bpf_conformance_test_result_t, std::string>>
 bpf_conformance_options(
     const std::vector<std::filesystem::path>& test_files,
@@ -178,28 +190,8 @@ bpf_conformance_options(
         // Determine the required CPU version for the test.
         for (size_t i = 0; i < byte_code.size(); i++) {
             auto inst = byte_code[i];
-            // If this is an atomic store, then the test requires CPU version 3.
-            if (((inst.opcode & EBPF_CLS_MASK) == EBPF_CLS_STX) &&
-                (((inst.opcode & EBPF_MODE_ATOMIC) == EBPF_MODE_ATOMIC))) {
-                required_cpu_version = std::max(required_cpu_version, bpf_conformance_test_cpu_version_t::v3);
-            }
-            // If this is a EBPF_CLS_JMP32, then we know this is v3.
-            else if ((inst.opcode & EBPF_CLS_MASK) == EBPF_CLS_JMP32) {
-                required_cpu_version = std::max(required_cpu_version, bpf_conformance_test_cpu_version_t::v3);
-            } else if ((inst.opcode & EBPF_CLS_MASK) == EBPF_CLS_JMP) {
-                // If this is a EBPF_CLS_JMP, then check if it is a less than operation.
-                if ((inst.opcode & EBPF_ALU_OP_MASK) >= (EBPF_OP_JLT_IMM & EBPF_ALU_OP_MASK)) {
-                    // It his is a less than operation, then we know this is v2.
-                    required_cpu_version = std::max(required_cpu_version, bpf_conformance_test_cpu_version_t::v2);
-                }
-            }
-            // If the program uses local or runtime calls then this is v3 of the ABI.
-            // inst.src == 0 means helper function call.
-            // inst.src == 1 means local function call.
-            // inst.src == 2 means runtime function call.
-            if (inst.opcode == EBPF_OP_CALL && inst.src != 0) {
-                required_cpu_version = std::max(required_cpu_version, bpf_conformance_test_cpu_version_t::v3);
-            }
+            bpf_conformance_test_cpu_version_t cpu_version = get_instruction_cpu_version(inst);
+	    required_cpu_version = std::max(required_cpu_version, cpu_version);
             if (inst.opcode == EBPF_OP_LDDW) {
                 // Instruction has a 64-bit immediate and takes two instructions slots.
                 i++;
@@ -215,7 +207,7 @@ bpf_conformance_options(
         }
 
         for (const auto& inst : byte_code) {
-            instructions_used.insert(bpf_conformance_instruction_t(inst));
+            instructions_used.insert(bpf_conformance_instruction_t(required_cpu_version, inst));
         }
 
         // If the caller requires this as a XDP program, then add the prolog instructions.
@@ -302,7 +294,7 @@ bpf_conformance_options(
                 }
                 if (expected_error_string.empty()) {
                     test_results[test] = {
-                        bpf_conformance_test_result_t::TEST_RESULT_FAIL,
+                        bpf_conformance_test_result_t::TEST_RESULT_ERROR,
                         "Plugin returned error code " + std::to_string(c.exit_code()) + " and output " +
                             return_value_string};
                 } else {