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>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2021-05-24 06:57:50 -04:00
parent 4db4385a7a
commit 3770141139
3 changed files with 76 additions and 33 deletions

View File

@ -1,6 +1,8 @@
#ifndef QEMU_CONFIG_FILE_H #ifndef QEMU_CONFIG_FILE_H
#define 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); void qemu_load_module_for_opts(const char *group);
QemuOptsList *qemu_find_opts(const char *group); QemuOptsList *qemu_find_opts(const char *group);
QemuOptsList *qemu_find_opts_err(const char *group, Error **errp); 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, int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname,
Error **errp); 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 /* Parse QDict options as a replacement for a config file (allowing multiple
enumerated (0..(n-1)) configuration "sections") */ enumerated (0..(n-1)) configuration "sections") */

View File

@ -2133,7 +2133,7 @@ static void qemu_read_default_config_file(Error **errp)
int ret; int ret;
g_autofree char *file = get_relocated_path(CONFIG_QEMU_CONFDIR "/qemu.conf"); 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 < 0) {
if (ret == -ENOENT) { if (ret == -ENOENT) {
error_free(*errp); error_free(*errp);
@ -3399,7 +3399,7 @@ void qemu_init(int argc, char **argv, char **envp)
qemu_plugin_opt_parse(optarg, &plugin_list); qemu_plugin_opt_parse(optarg, &plugin_list);
break; break;
case QEMU_OPTION_readconfig: case QEMU_OPTION_readconfig:
qemu_read_config_file(optarg, &error_fatal); qemu_read_config_file(optarg, qemu_config_do_parse, &error_fatal);
break; break;
case QEMU_OPTION_spice: case QEMU_OPTION_spice:
olist = qemu_find_opts_err("spice", NULL); olist = qemu_find_opts_err("spice", NULL);

View File

@ -2,6 +2,7 @@
#include "block/qdict.h" /* for qdict_extract_subqdict() */ #include "block/qdict.h" /* for qdict_extract_subqdict() */
#include "qapi/error.h" #include "qapi/error.h"
#include "qapi/qapi-commands-misc.h" #include "qapi/qapi-commands-misc.h"
#include "qapi/qmp/qerror.h"
#include "qapi/qmp/qdict.h" #include "qapi/qmp/qdict.h"
#include "qapi/qmp/qlist.h" #include "qapi/qmp/qlist.h"
#include "qemu/error-report.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 */ /* 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; Location loc;
QemuOptsList *list = NULL;
Error *local_err = NULL; Error *local_err = NULL;
QemuOpts *opts = NULL; QDict *qdict = NULL;
int res = -EINVAL, lno = 0; int res = -EINVAL, lno = 0;
int count = 0; int count = 0;
loc_push_none(&loc); loc_push_none(&loc);
while (fgets(line, sizeof(line), fp) != NULL) { while (fgets(line, sizeof(line), fp) != NULL) {
loc_set_file(fname, ++lno); ++lno;
if (line[0] == '\n') { if (line[0] == '\n') {
/* skip empty lines */ /* skip empty lines */
continue; continue;
@ -372,39 +373,39 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname, Error *
/* comment */ /* comment */
continue; continue;
} }
if (sscanf(line, "[%63s \"%63[^\"]\"]", group, id) == 2) { if (line[0] == '[') {
/* group with id */ QDict *prev = qdict;
list = find_list(lists, group, &local_err); 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++;
}
if (qdict != prev) {
if (prev) {
cb(prev_group, prev, opaque, &local_err);
qobject_unref(prev);
if (local_err) { if (local_err) {
error_propagate(errp, local_err); error_propagate(errp, local_err);
goto out; goto out;
} }
opts = qemu_opts_create(list, id, 1, NULL); }
count++; strcpy(prev_group, group);
continue; 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;
}
opts = qemu_opts_create(list, NULL, 0, &error_abort);
count++;
continue;
} }
loc_set_file(fname, lno);
value[0] = '\0'; value[0] = '\0';
if (sscanf(line, " %63s = \"%1023[^\"]\"", arg, value) == 2 || if (sscanf(line, " %63s = \"%1023[^\"]\"", arg, value) == 2 ||
sscanf(line, " %63s = \"\"", arg) == 1) { sscanf(line, " %63s = \"\"", arg) == 1) {
/* arg = value */ /* arg = value */
if (opts == NULL) { if (qdict == NULL) {
error_setg(errp, "no group defined"); error_setg(errp, "no group defined");
goto out; goto out;
} }
if (!qemu_opt_set(opts, arg, value, errp)) { qdict_put_str(qdict, arg, value);
goto out;
}
continue; continue;
} }
error_setg(errp, "parse error"); error_setg(errp, "parse error");
@ -417,11 +418,48 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname, Error *
} }
res = count; res = count;
out: out:
if (qdict) {
cb(group, qdict, opaque, errp);
qobject_unref(qdict);
}
loc_pop(&loc); loc_pop(&loc);
return res; 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)) {
qemu_opts_del(opts);
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"); FILE *f = fopen(filename, "r");
int ret; int ret;
@ -431,7 +469,7 @@ int qemu_read_config_file(const char *filename, Error **errp)
return -errno; 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); fclose(f);
return ret; return ret;
} }