Forbid ids if the option is intended to be a singleton, as indicated by list->merge_lists. This avoids that "./qemu-system-x86_64 -M q35,id=ff" uses a "pc" machine type. Instead it errors out. The affected options are "qemu-img reopen -o", "qemu-io open -o", -rtc, -M, -boot, -name, -m, -icount, -smp, -spice.
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. Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- util/qemu-option.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/util/qemu-option.c b/util/qemu-option.c index c88e159f18..91f4120ce1 100644 --- a/util/qemu-option.c +++ b/util/qemu-option.c @@ -619,7 +619,17 @@ QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id, { 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 @@ QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id, } 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 @@ static QemuOpts *opts_parse(QemuOptsList *list, const char *params, * (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; -- 2.26.2