qemu-option: clean up id vs. list->merge_lists
Looking at all merge-lists QemuOptsList, here is how they access their
QemuOpts:
reopen_opts in qemu-io-cmds.c ("qemu-img reopen -o")
qemu_opts_find(&reopen_opts, NULL)
empty_opts in qemu-io.c ("qemu-io open -o")
qemu_opts_find(&empty_opts, NULL)
qemu_rtc_opts ("-rtc")
qemu_find_opts_singleton("rtc")
qemu_machine_opts ("-M")
qemu_find_opts_singleton("machine")
qemu_action_opts ("-name")
qemu_opts_foreach->process_runstate_actions
qemu_boot_opts ("-boot")
in hw/nvram/fw_cfg.c and hw/s390x/ipl.c:
QTAILQ_FIRST(&qemu_find_opts("bootopts")->head)
in softmmu/vl.c:
qemu_opts_find(qemu_find_opts("boot-opts"), NULL)
qemu_name_opts ("-name")
qemu_opts_foreach->parse_name
parse_name does not use id
qemu_mem_opts ("-m")
qemu_find_opts_singleton("memory")
qemu_icount_opts ("-icount")
qemu_opts_foreach->do_configure_icount
do_configure_icount->icount_configure
icount_configure does not use id
qemu_smp_opts ("-smp")
qemu_opts_find(qemu_find_opts("smp-opts"), NULL)
qemu_spice_opts ("-spice")
QTAILQ_FIRST(&qemu_spice_opts.head)
i.e. they don't need an id. Sometimes its presence is ignored
(e.g. when using qemu_opts_foreach), sometimes all the options
with the id are skipped, sometimes only the first option on the
command line is considered. -boot does two different things
depending on who's looking at the options.
With this patch we just forbid id on merge-lists QemuOptsLists; if the
command line still works, it has the same semantics as before.
qemu_opts_create's fail_if_exists parameter is now unnecessary:
- it is unused if id is NULL
- opts_parse only passes false if reached from qemu_opts_set_defaults,
in which case this patch enforces that id must be NULL
- other callers that can pass a non-NULL id always set it to true
Assert that it is true in the only case where "fail_if_exists" matters,
i.e. "id && !lists->merge_lists". This means that if an id is present,
duplicates are always forbidden, which was already the status quo.
Discounting the case that aborts as it's not user-controlled (it's
"just" a matter of inspecting qemu_opts_create callers), the paths
through qemu_opts_create can be summarized as:
- merge_lists = true: singleton opts with NULL id; non-NULL id fails
- merge_lists = false: always return new opts; non-NULL id fails if dup
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/util/qemu-option.c b/util/qemu-option.c
index c88e159..91f4120 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -619,7 +619,17 @@
{
QemuOpts *opts = NULL;
- if (id) {
+ if (list->merge_lists) {
+ if (id) {
+ error_setg(errp, QERR_INVALID_PARAMETER, "id");
+ return NULL;
+ }
+ opts = qemu_opts_find(list, NULL);
+ if (opts) {
+ return opts;
+ }
+ } else if (id) {
+ assert(fail_if_exists);
if (!id_wellformed(id)) {
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id",
"an identifier");
@@ -629,17 +639,8 @@
}
opts = qemu_opts_find(list, id);
if (opts != NULL) {
- if (fail_if_exists && !list->merge_lists) {
- error_setg(errp, "Duplicate ID '%s' for %s", id, list->name);
- return NULL;
- } else {
- return opts;
- }
- }
- } else if (list->merge_lists) {
- opts = qemu_opts_find(list, NULL);
- if (opts) {
- return opts;
+ error_setg(errp, "Duplicate ID '%s' for %s", id, list->name);
+ return NULL;
}
}
opts = g_malloc0(sizeof(*opts));
@@ -893,7 +894,7 @@
* (if unlikely) future misuse:
*/
assert(!defaults || list->merge_lists);
- opts = qemu_opts_create(list, id, !defaults, errp);
+ opts = qemu_opts_create(list, id, !list->merge_lists, errp);
g_free(id);
if (opts == NULL) {
return NULL;
