[PATCH 2/3] plugins/execlog: add data address match

[Sven Schnelle <svens@stackframe.org>]

Add a match similar to the afilter address match, but for data
addresses. When an address is specified with '-dfilter=0x12345'
only load/stores to/from address 0x12345 are printed. All other
instructions are hidden.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
---
 contrib/plugins/execlog.c | 32 ++++++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)

diff --git a/contrib/plugins/execlog.c b/contrib/plugins/execlog.c
index 934553e83d..c89ebc08b6 100644
--- a/contrib/plugins/execlog.c
+++ b/contrib/plugins/execlog.c
@@ -27,6 +27,8 @@ typedef struct CPU {
     GString *last_exec;
     /* Ptr array of Register */
     GPtrArray *registers;
+    /* whether this instruction should be logged */
+    bool log;
 } CPU;
 
 QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION;
@@ -36,6 +38,7 @@ static GRWLock expand_array_lock;
 
 static GPtrArray *imatches;
 static GArray *amatches;
+static GArray *dmatches;
 static GPtrArray *rmatches;
 static bool disas_assist;
 static GMutex add_reg_name_lock;
@@ -51,6 +54,17 @@ static CPU *get_cpu(int vcpu_index)
     return c;
 }
 
+static bool match_vaddr(uint64_t vaddr)
+{
+    for (int i = 0; i < dmatches->len; i++) {
+        uint64_t v = g_array_index(dmatches, uint64_t, i);
+        if (v == vaddr) {
+            return true;
+        }
+    }
+    return false;
+}
+
 /**
  * Add memory read or write information to current instruction log
  */
@@ -62,6 +76,11 @@ static void vcpu_mem(unsigned int cpu_index, qemu_plugin_meminfo_t info,
 
     /* Find vCPU in array */
 
+    if (dmatches && !match_vaddr(vaddr)) {
+        return;
+    }
+    c->log = true;
+
     /* Indicate type of memory access */
     if (qemu_plugin_mem_is_store(info)) {
         g_string_append(s, ", store");
@@ -121,15 +140,17 @@ static void vcpu_insn_exec_with_regs(unsigned int cpu_index, void *udata)
         if (cpu->registers) {
             insn_check_regs(cpu);
         }
-
-        qemu_plugin_outs(cpu->last_exec->str);
-        qemu_plugin_outs("\n");
+        if (cpu->log) {
+            qemu_plugin_outs(cpu->last_exec->str);
+            qemu_plugin_outs("\n");
+        }
     }
 
     /* Store new instruction in cache */
     /* vcpu_mem will add memory access information to last_exec */
     g_string_printf(cpu->last_exec, "%u, ", cpu_index);
     g_string_append(cpu->last_exec, (char *)udata);
+    cpu->log = dmatches ? false : true;
 }
 
 /* Log last instruction while checking registers, ignore next */
@@ -166,6 +187,7 @@ static void vcpu_insn_exec(unsigned int cpu_index, void *udata)
     /* vcpu_mem will add memory access information to last_exec */
     g_string_printf(cpu->last_exec, "%u, ", cpu_index);
     g_string_append(cpu->last_exec, (char *)udata);
+    cpu->log = dmatches ? false : true;
 }
 
 /**
@@ -381,7 +403,7 @@ static void plugin_exit(qemu_plugin_id_t id, void *p)
     g_rw_lock_reader_lock(&expand_array_lock);
     for (i = 0; i < cpus->len; i++) {
         CPU *c = get_cpu(i);
-        if (c->last_exec && c->last_exec->str) {
+        if (c->log && c->last_exec && c->last_exec->str) {
             qemu_plugin_outs(c->last_exec->str);
             qemu_plugin_outs("\n");
         }
@@ -441,6 +463,8 @@ QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
             parse_insn_match(tokens[1]);
         } else if (g_strcmp0(tokens[0], "afilter") == 0) {
             parse_vaddr_match(&amatches, tokens[1]);
+        } else if (g_strcmp0(tokens[0], "dfilter") == 0) {
+            parse_vaddr_match(&dmatches, tokens[1]);
         } else if (g_strcmp0(tokens[0], "reg") == 0) {
             add_regpat(tokens[1]);
         } else if (g_strcmp0(tokens[0], "rdisas") == 0) {
-- 
2.43.2