From 4eb647d7081b3090ba949a129756f7f7a42abf5a Mon Sep 17 00:00:00 2001
From: john cooper <john.cooper@redhat.com>
Date: Sat, 11 Dec 2010 04:30:10 -0200
Subject: [PATCH 01/24] Bug #625333 - qemu treatment of -nodefconfig and -readconfig problematic for debug
RH-Author: john cooper <john.cooper@redhat.com>
Message-id: <4D02FE52.7050405@redhat.com>
Patchwork-id: 14538
O-Subject: [RHEL6.1 PATCH v3] Bug #625333 - qemu treatment of -nodefconfig and
-readconfig problematic for debug
Bugzilla: 625333
RH-Acked-by: Amit Shah <amit.shah@redhat.com>
RH-Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
RH-Acked-by: Alex Williamson <alex.williamson@redhat.com>
The prior version of this patch had the side effect of allowing a
-readconfig specified config file to be overridden by a wired-in
default config file. Although this scenario would not occur in
the context of a libvirt launch, altering semantics relative to
upstream qemu is best avoided.
Details:
The problem is qemu currently has only two discrete scans of CLI
arguments. Trying to live within that structure while supporting
flags which affect other flags is problematic. Qemu attempts to
implement flag semantics simultaneous with their parsing. As such
semantic actions follow the unpredictable sequence of args appearing
on the command like.
This patch therefore enforces consistent ordering of the following
semantics as:
- interpret config file parse modifiers
- conditionally read default qemu configs
- read local cpu config
- read any -readconfig configs
- interpret all other options
Testing:
- The config file processing order above should be in effect.
Specifically an identical data item in a later config file
should redefine the same introduced by a prior config file.
- Default and local config files may or may not exist on the
host. If they do not exist, they are quietly ignored unless
verbose handling by "-readconfig ?" is specified. However if
any do exist and contain config file format errors, qemu will
error exit.
- Handling of config files specified by "-readconfig <file>"
is the same as default/local config files with the addition
qemu will error exit if <file> cannot be opened for read.
- any sequence of "-readconfig" | "-nodefconfig" | "-cpu" has the
same effect irrespective of relative location in the command line
Upstream Status:
This patch has seen modification in the process of trying to push it
upstream, which resulted in minor syntax changes to the CLI. We will
need to accommodate this when we rebase qemu.
Signed-off-by: john cooper <john.cooper@redhat.com>
---
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
vl.c | 51 ++++++++++++++++++++++++++++++++++++++-------------
1 files changed, 38 insertions(+), 13 deletions(-)
diff --git a/vl.c b/vl.c
index 734a5b2..cac6921 100644
--- a/vl.c
+++ b/vl.c
@@ -5325,7 +5325,8 @@ int main(int argc, char **argv, char **envp)
tb_size = 0;
autostart= 1;
- /* first pass of option parsing */
+ /* first pass of CLI options -- interpret config file parse modifiers
+ */
optind = 1;
while (optind < argc) {
if (argv[optind][0] != '-') {
@@ -5349,13 +5350,8 @@ int main(int argc, char **argv, char **envp)
}
}
- /* load local cpu config, NB: may possibly be overridden by defconfigs
+ /* pull in default configs unless explicitly disabled
*/
- if (qemu_read_config_file(
- CONFIG_QEMU_CPUCONFDIR "/cpu-" TARGET_ARCH ".conf",
- defconfig_verbose) == -EINVAL) {
- exit(1);
- }
if (defconfig) {
int ret;
@@ -5372,11 +5368,45 @@ int main(int argc, char **argv, char **envp)
exit(1);
}
}
+
+ /* load local cpu config
+ */
+ if (qemu_read_config_file(
+ CONFIG_QEMU_CPUCONFDIR "/cpu-" TARGET_ARCH ".conf",
+ defconfig_verbose) == -EINVAL) {
+ exit(1);
+ }
+
+ /* second pass of CLI options -- bring in any -readconfig flags
+ */
+ optind = 1;
+ while (optind < argc) {
+ if (argv[optind][0] != '-') {
+ /* disk image */
+ optind++;
+ continue;
+ } else {
+ const QEMUOption *popt;
+
+ popt = lookup_opt(argc, argv, &optarg, &optind);
+ switch (popt->index) {
+ case QEMU_OPTION_readconfig:
+ /* pull in cli specified config files in advance of general
+ * flag parsing which may reference their content
+ */
+ if (strcmp(optarg, "?") &&
+ qemu_read_config_file(optarg, defconfig_verbose) < 0)
+ exit(1);
+ break;
+ }
+ }
+ }
#if defined(cpudef_setup)
cpudef_setup(); /* parse cpu definitions in target config file */
#endif
- /* second pass of option parsing */
+ /* third pass of CLI options -- general flag interpretation
+ */
optind = 1;
for(;;) {
if (optind >= argc)
@@ -6084,11 +6114,6 @@ int main(int argc, char **argv, char **envp)
xen_mode = XEN_ATTACH;
break;
#endif
- case QEMU_OPTION_readconfig:
- if (!!strcmp(optarg, "?") &&
- qemu_read_config_file(optarg, defconfig_verbose) < 0)
- exit(1);
- break;
case QEMU_OPTION_spice:
olist = qemu_find_opts("spice");
if (!olist) {
--
1.7.4.rc1.16.gd2f15e