From a0520e180e6f235b8a3a531b0756e45cbfe36e15 Mon Sep 17 00:00:00 2001

From: Paolo Bonzini <pbonzini@redhat.com>

Date: Tue, 18 May 2021 11:40:57 -0400

Subject: [PATCH 3/5] qemu-config: parse configuration files to a QDict

Change the parser to put the values into a QDict and pass them

to a callback.  qemu_config_parse's QemuOpts creation is

itself turned into a callback function.

This is useful for -readconfig to support keyval-based options;

getting a QDict from the parser removes a roundtrip from

QDict to QemuOpts and then back to QDict.

Unfortunately there is a disadvantage in that semantic errors will

point to the last line of the group, because the entries of the QDict

do not have a location attached.

Cc: Kevin Wolf <kwolf@redhat.com>

Cc: Markus Armbruster <armbru@redhat.com>

Cc: qemu-stable@nongnu.org

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Message-Id: <20210524105752.3318299-2-pbonzini@redhat.com>

---

 include/qemu/config-file.h |  7 ++-

 softmmu/vl.c               |  4 +-

 util/qemu-config.c         | 97 ++++++++++++++++++++++++++------------

 3 files changed, 75 insertions(+), 33 deletions(-)

diff --git a/include/qemu/config-file.h b/include/qemu/config-file.h

index 0500b36..f605423 100644

--- a/include/qemu/config-file.h

+++ b/include/qemu/config-file.h

@@ -1,6 +1,8 @@

 #ifndef QEMU_CONFIG_FILE_H

 #define QEMU_CONFIG_FILE_H

+typedef void QEMUConfigCB(const char *group, QDict *qdict, void *opaque, Error **errp);

+

 void qemu_load_module_for_opts(const char *group);

 QemuOptsList *qemu_find_opts(const char *group);

 QemuOptsList *qemu_find_opts_err(const char *group, Error **errp);

@@ -14,7 +16,10 @@ void qemu_config_write(FILE *fp);

 int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname,

                       Error **errp);

-int qemu_read_config_file(const char *filename, Error **errp);

+/* A default callback for qemu_read_config_file().  */

+void qemu_config_do_parse(const char *group, QDict *qdict, void *opaque, Error **errp);

+

+int qemu_read_config_file(const char *filename, QEMUConfigCB *f, Error **errp);

 /* Parse QDict options as a replacement for a config file (allowing multiple

    enumerated (0..(n-1)) configuration "sections") */

diff --git a/softmmu/vl.c b/softmmu/vl.c

index 4641f08..da5042f 100644

--- a/softmmu/vl.c

+++ b/softmmu/vl.c

@@ -2119,7 +2119,7 @@ static void qemu_read_default_config_file(Error **errp)

     int ret;

     g_autofree char *file = get_relocated_path(CONFIG_QEMU_CONFDIR "/qemu.conf");

-    ret = qemu_read_config_file(file, errp);

+    ret = qemu_read_config_file(file, qemu_config_do_parse, errp);

     if (ret < 0) {

         if (ret == -ENOENT) {

             error_free(*errp);

@@ -3385,7 +3385,7 @@ void qemu_init(int argc, char **argv, char **envp)

                 qemu_plugin_opt_parse(optarg, &plugin_list);

                 break;

             case QEMU_OPTION_readconfig:

-                qemu_read_config_file(optarg, &error_fatal);

+                qemu_read_config_file(optarg, qemu_config_do_parse, &error_fatal);

                 break;

             case QEMU_OPTION_spice:

                 olist = qemu_find_opts_err("spice", NULL);

diff --git a/util/qemu-config.c b/util/qemu-config.c

index 34974c4..f6eaff9 100644

--- a/util/qemu-config.c

+++ b/util/qemu-config.c

@@ -2,6 +2,7 @@

 #include "block/qdict.h" /* for qdict_extract_subqdict() */

 #include "qapi/error.h"

 #include "qapi/qapi-commands-misc.h"

+#include "qapi/qmp/qerror.h"

 #include "qapi/qmp/qdict.h"

 #include "qapi/qmp/qlist.h"

 #include "qemu/error-report.h"

@@ -351,19 +352,19 @@ void qemu_config_write(FILE *fp)

 }

 /* Returns number of config groups on success, -errno on error */

-int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname, Error **errp)

+static int qemu_config_foreach(FILE *fp, QEMUConfigCB *cb, void *opaque,

+                               const char *fname, Error **errp)

 {

-    char line[1024], group[64], id[64], arg[64], value[1024];

+    char line[1024], prev_group[64], group[64], arg[64], value[1024];

     Location loc;

-    QemuOptsList *list = NULL;

     Error *local_err = NULL;

-    QemuOpts *opts = NULL;

+    QDict *qdict = NULL;

     int res = -EINVAL, lno = 0;

     int count = 0;

     loc_push_none(&loc;;

     while (fgets(line, sizeof(line), fp) != NULL) {

-        loc_set_file(fname, ++lno);

+        ++lno;

         if (line[0] == '\n') {

             /* skip empty lines */

             continue;

@@ -372,39 +373,39 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname, Error *

             /* comment */

             continue;

         }

-        if (sscanf(line, "[%63s \"%63[^\"]\"]", group, id) == 2) {

-            /* group with id */

-            list = find_list(lists, group, &local_err);

-            if (local_err) {

-                error_propagate(errp, local_err);

-                goto out;

+        if (line[0] == '[') {

+            QDict *prev = qdict;

+            if (sscanf(line, "[%63s \"%63[^\"]\"]", group, value) == 2) {

+                qdict = qdict_new();

+                qdict_put_str(qdict, "id", value);

+                count++;

+            } else if (sscanf(line, "[%63[^]]]", group) == 1) {

+                qdict = qdict_new();

+                count++;

             }

-            opts = qemu_opts_create(list, id, 1, NULL);

-            count++;

-            continue;

-        }

-        if (sscanf(line, "[%63[^]]]", group) == 1) {

-            /* group without id */

-            list = find_list(lists, group, &local_err);

-            if (local_err) {

-                error_propagate(errp, local_err);

-                goto out;

+            if (qdict != prev) {

+                if (prev) {

+                    cb(prev_group, prev, opaque, &local_err);

+                    qobject_unref(prev);

+                    if (local_err) {

+                        error_propagate(errp, local_err);

+                        goto out;

+                    }

+                }

+                strcpy(prev_group, group);

+                continue;

             }

-            opts = qemu_opts_create(list, NULL, 0, &error_abort);

-            count++;

-            continue;

         }

+        loc_set_file(fname, lno);

         value[0] = '\0';

         if (sscanf(line, " %63s = \"%1023[^\"]\"", arg, value) == 2 ||

             sscanf(line, " %63s = \"\"", arg) == 1) {

             /* arg = value */

-            if (opts == NULL) {

+            if (qdict == NULL) {

                 error_setg(errp, "no group defined");

                 goto out;

             }

-            if (!qemu_opt_set(opts, arg, value, errp)) {

-                goto out;

-            }

+            qdict_put_str(qdict, arg, value);

             continue;

         }

         error_setg(errp, "parse error");

@@ -417,11 +418,47 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname, Error *

     }

     res = count;

 out:

+    if (qdict) {

+        cb(group, qdict, opaque, errp);

+        qobject_unref(qdict);

+    }

     loc_pop(&loc;;

     return res;

 }

-int qemu_read_config_file(const char *filename, Error **errp)

+void qemu_config_do_parse(const char *group, QDict *qdict, void *opaque, Error **errp)

+{

+    QemuOptsList **lists = opaque;

+    const char *id = qdict_get_try_str(qdict, "id");

+    QemuOptsList *list;

+    QemuOpts *opts;

+    const QDictEntry *unrecognized;

+

+    list = find_list(lists, group, errp);

+    if (!list) {

+        return;

+    }

+

+    opts = qemu_opts_create(list, id, 1, errp);

+    if (!opts) {

+        return;

+    }

+    if (!qemu_opts_absorb_qdict(opts, qdict, errp)) {

+        return;

+    }

+    unrecognized = qdict_first(qdict);

+    if (unrecognized) {

+        error_setg(errp, QERR_INVALID_PARAMETER, unrecognized->key);

+        qemu_opts_del(opts);

+    }

+}

+

+int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname, Error **errp)

+{

+    return qemu_config_foreach(fp, qemu_config_do_parse, lists, fname, errp);

+}

+

+int qemu_read_config_file(const char *filename, QEMUConfigCB *cb, Error **errp)

 {

     FILE *f = fopen(filename, "r");

     int ret;

@@ -431,7 +468,7 @@ int qemu_read_config_file(const char *filename, Error **errp)

         return -errno;

     }

-    ret = qemu_config_parse(f, vm_config_groups, filename, errp);

+    ret = qemu_config_foreach(f, cb, vm_config_groups, filename, errp);

     fclose(f);

     return ret;

 }

-- 

2.31.1