plugins/howvec: adapting to the new argument passing scheme

Correctly parsing plugin argument since they now must be provided as
full-form boolean parameters, e.g.:
    -plugin ./contrib/plugins/libhowvec.so,verbose=on,inline=on

Also, introduced the argument "count" that accepts one opt to count
individually at a time.

Signed-off-by: Mahmoud Mandour <ma.mandourr@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210730135817.17816-8-ma.mandourr@gmail.com>

contrib/plugins/howvec.c

@@ -333,23 +333,34 @@ QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
 
     for (i = 0; i < argc; i++) {
         char *p = argv[i];
-        if (strcmp(p, "inline") == 0) {
-            do_inline = true;
-        } else if (strcmp(p, "verbose") == 0) {
-            verbose = true;
-        } else {
+        g_autofree char **tokens = g_strsplit(p, "=", -1);
+        if (g_strcmp0(tokens[0], "inline") == 0) {
+            if (!qemu_plugin_bool_parse(tokens[0], tokens[1], &do_inline)) {
+                fprintf(stderr, "boolean argument parsing failed: %s\n", p);
+                return -1;
+            }
+        } else if (g_strcmp0(tokens[0], "verbose") == 0) {
+            if (!qemu_plugin_bool_parse(tokens[0], tokens[1], &verbose)) {
+                fprintf(stderr, "boolean argument parsing failed: %s\n", p);
+                return -1;
+            }
+        } else if (g_strcmp0(tokens[0], "count") == 0) {
+            char *value = tokens[1];
             int j;
             CountType type = COUNT_INDIVIDUAL;
-            if (*p == '!') {
+            if (*value == '!') {
                 type = COUNT_NONE;
-                p++;
+                value++;
             }
             for (j = 0; j < class_table_sz; j++) {
-                if (strcmp(p, class_table[j].opt) == 0) {
+                if (strcmp(value, class_table[j].opt) == 0) {
                     class_table[j].what = type;
                     break;
                 }
             }
+        } else {
+            fprintf(stderr, "option parsing failed: %s\n", p);
+            return -1;
         }
     }
 

docs/devel/tcg-plugins.rst

@@ -80,7 +80,7 @@ Once built a program can be run with multiple plugins loaded each with
 their own arguments::
 
   $QEMU $OTHER_QEMU_ARGS \
-      -plugin tests/plugin/libhowvec.so,arg=inline,arg=hint \
+      -plugin tests/plugin/libhowvec.so,inline=on,count=hint \
       -plugin tests/plugin/libhotblocks.so
 
 Arguments are plugin specific and can be used to modify their
@@ -212,13 +212,13 @@ The hotpages plugin can be configured using the following arguments:
 
 This is an instruction classifier so can be used to count different
 types of instructions. It has a number of options to refine which get
-counted. You can give an argument for a class of instructions to break
-it down fully, so for example to see all the system registers
-accesses::
+counted. You can give a value to the `count` argument for a class of
+instructions to break it down fully, so for example to see all the system
+registers accesses::
 
   ./aarch64-softmmu/qemu-system-aarch64 $(QEMU_ARGS) \
     -append "root=/dev/sda2 systemd.unit=benchmark.service" \
-    -smp 4 -plugin ./contrib/plugins/libhowvec.so,arg=sreg -d plugin
+    -smp 4 -plugin ./contrib/plugins/libhowvec.so,count=sreg -d plugin
 
 which will lead to a sorted list after the class breakdown::