tests/tcg/plugins/mem: add option to print memory accesses

By using "print-accesses=true" option, mem plugin will now print every
value accessed, with associated size, type (store vs load), symbol,
instruction address and phys/virt address accessed.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Xingtao Yao <yaoxt.fnst@fujitsu.com>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-Id: <20240724194708.1843704-6-pierrick.bouvier@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240916085400.1046925-9-alex.bennee@linaro.org>

tests/tcg/plugins/mem.c

@@ -21,10 +21,15 @@ typedef struct {
     uint64_t io_count;
 } CPUCount;
 
+typedef struct {
+    uint64_t vaddr;
+    const char *sym;
+} InsnInfo;
+
 static struct qemu_plugin_scoreboard *counts;
 static qemu_plugin_u64 mem_count;
 static qemu_plugin_u64 io_count;
-static bool do_inline, do_callback;
+static bool do_inline, do_callback, do_print_accesses;
 static bool do_haddr;
 static enum qemu_plugin_mem_rw rw = QEMU_PLUGIN_MEM_RW;
 
@@ -60,6 +65,44 @@ static void vcpu_mem(unsigned int cpu_index, qemu_plugin_meminfo_t meminfo,
     }
 }
 
+static void print_access(unsigned int cpu_index, qemu_plugin_meminfo_t meminfo,
+                         uint64_t vaddr, void *udata)
+{
+    InsnInfo *insn_info = udata;
+    unsigned size = 8 << qemu_plugin_mem_size_shift(meminfo);
+    const char *type = qemu_plugin_mem_is_store(meminfo) ? "store" : "load";
+    qemu_plugin_mem_value value = qemu_plugin_mem_get_value(meminfo);
+    uint64_t hwaddr =
+        qemu_plugin_hwaddr_phys_addr(qemu_plugin_get_hwaddr(meminfo, vaddr));
+    g_autoptr(GString) out = g_string_new("");
+    g_string_printf(out,
+                    "0x%"PRIx64",%s,0x%"PRIx64",0x%"PRIx64",%d,%s,",
+                    insn_info->vaddr, insn_info->sym,
+                    vaddr, hwaddr, size, type);
+    switch (value.type) {
+    case QEMU_PLUGIN_MEM_VALUE_U8:
+        g_string_append_printf(out, "0x%02"PRIx8, value.data.u8);
+        break;
+    case QEMU_PLUGIN_MEM_VALUE_U16:
+        g_string_append_printf(out, "0x%04"PRIx16, value.data.u16);
+        break;
+    case QEMU_PLUGIN_MEM_VALUE_U32:
+        g_string_append_printf(out, "0x%08"PRIx32, value.data.u32);
+        break;
+    case QEMU_PLUGIN_MEM_VALUE_U64:
+        g_string_append_printf(out, "0x%016"PRIx64, value.data.u64);
+        break;
+    case QEMU_PLUGIN_MEM_VALUE_U128:
+        g_string_append_printf(out, "0x%016"PRIx64"%016"PRIx64,
+                               value.data.u128.high, value.data.u128.low);
+        break;
+    default:
+        g_assert_not_reached();
+    }
+    g_string_append_printf(out, "\n");
+    qemu_plugin_outs(out->str);
+}
+
 static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
 {
     size_t n = qemu_plugin_tb_n_insns(tb);
@@ -79,6 +122,16 @@ static void vcpu_tb_trans(qemu_plugin_id_t id, struct qemu_plugin_tb *tb)
                                              QEMU_PLUGIN_CB_NO_REGS,
                                              rw, NULL);
         }
+        if (do_print_accesses) {
+            /* we leak this pointer, to avoid locking to keep track of it */
+            InsnInfo *insn_info = g_malloc(sizeof(InsnInfo));
+            const char *sym = qemu_plugin_insn_symbol(insn);
+            insn_info->sym = sym ? sym : "";
+            insn_info->vaddr = qemu_plugin_insn_vaddr(insn);
+            qemu_plugin_register_vcpu_mem_cb(insn, print_access,
+                                             QEMU_PLUGIN_CB_NO_REGS,
+                                             rw, (void *) insn_info);
+        }
     }
 }
 
@@ -117,6 +170,12 @@ QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
                 fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
                 return -1;
             }
+        } else if (g_strcmp0(tokens[0], "print-accesses") == 0) {
+            if (!qemu_plugin_bool_parse(tokens[0], tokens[1],
+                                        &do_print_accesses)) {
+                fprintf(stderr, "boolean argument parsing failed: %s\n", opt);
+                return -1;
+            }
         } else {
             fprintf(stderr, "option parsing failed: %s\n", opt);
             return -1;
@@ -129,6 +188,14 @@ QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
         return -1;
     }
 
+    if (do_print_accesses) {
+        g_autoptr(GString) out = g_string_new("");
+        g_string_printf(out,
+                "insn_vaddr,insn_symbol,mem_vaddr,mem_hwaddr,"
+                "access_size,access_type,mem_value\n");
+        qemu_plugin_outs(out->str);
+    }
+
     counts = qemu_plugin_scoreboard_new(sizeof(CPUCount));
     mem_count = qemu_plugin_scoreboard_u64_in_struct(
         counts, CPUCount, mem_count);