[Qemu-devel] [RFC][PATCH 1/7] qemu-config: qemu_read_config_file() reads the normal config file

[Kevin Wolf <kwolf@redhat.com>]

Introduce a new function qemu_read_config_file which reads the VM configuration
from a config file. Unlike qemu_config_parse it doesn't take a open file but a
filename and reduces code duplication as a side effect.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qemu-config.c |   15 +++++++++++++++
 qemu-config.h |    2 ++
 vl.c          |   34 +++++++++++++---------------------
 3 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/qemu-config.c b/qemu-config.c
index 246fae6..8166b5e 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -473,3 +473,18 @@ int qemu_config_parse(FILE *fp)
     }
     return 0;
 }
+
+int qemu_read_config_file(const char *filename)
+{
+    FILE *f = fopen(filename, "r");
+    if (f == NULL) {
+        return -errno;
+    }
+
+    if (qemu_config_parse(f) != 0) {
+        return -EINVAL;
+    }
+    fclose(f);
+
+    return 0;
+}
diff --git a/qemu-config.h b/qemu-config.h
index b335c42..bbe9d41 100644
--- a/qemu-config.h
+++ b/qemu-config.h
@@ -18,4 +18,6 @@ void qemu_add_globals(void);
 void qemu_config_write(FILE *fp);
 int qemu_config_parse(FILE *fp);
 
+int qemu_read_config_file(const char *filename);
+
 #endif /* QEMU_CONFIG_H */
diff --git a/vl.c b/vl.c
index a3e43ad..078e3f9 100644
--- a/vl.c
+++ b/vl.c
@@ -4940,21 +4940,17 @@ int main(int argc, char **argv, char **envp)
     }
 
     if (defconfig) {
-        FILE *fp;
-        fp = fopen(CONFIG_QEMU_CONFDIR "/qemu.conf", "r");
-        if (fp) {
-            if (qemu_config_parse(fp) != 0) {
-                exit(1);
-            }
-            fclose(fp);
+        int ret;
+
+        ret = qemu_read_config_file(CONFIG_QEMU_CONFDIR "/qemu.conf");
+        if (ret == -EINVAL) {
+            exit(1);
         }
 
-        fp = fopen(CONFIG_QEMU_CONFDIR "/target-" TARGET_ARCH ".conf", "r");
-        if (fp) {
-            if (qemu_config_parse(fp) != 0) {
-                exit(1);
-            }
-            fclose(fp);
+        ret = qemu_read_config_file(CONFIG_QEMU_CONFDIR
+            "/target-" TARGET_ARCH ".conf");
+        if (ret == -EINVAL) {
+            exit(1);
         }
     }
 #if defined(cpudef_setup)
@@ -5635,16 +5631,12 @@ int main(int argc, char **argv, char **envp)
 #endif
             case QEMU_OPTION_readconfig:
                 {
-                    FILE *fp;
-                    fp = fopen(optarg, "r");
-                    if (fp == NULL) {
-                        fprintf(stderr, "open %s: %s\n", optarg, strerror(errno));
+                    int ret = qemu_read_config_file(optarg);
+                    if (ret < 0) {
+                        fprintf(stderr, "read config %s: %s\n", optarg,
+                            strerror(-ret));
                         exit(1);
                     }
-                    if (qemu_config_parse(fp) != 0) {
-                        exit(1);
-                    }
-                    fclose(fp);
                     break;
                 }
             case QEMU_OPTION_writeconfig:
-- 
1.6.6.1