From 32c02fdda49b8ace1517f1b95bfc215e0b92a154 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 9 Nov 2020 04:46:30 -0500 Subject: [PATCH] qemu-option: restrict qemu_opts_set to merge-lists QemuOpts qemu_opts_set is used to create default network backends and to parse sugar options -kernel, -initrd, -append, -bios and -dtb. These are very different uses: I would *expect* a function named qemu_opts_set to set an option in a merge-lists QemuOptsList, such as -kernel, and possibly to set an option in a non-merge-lists QemuOptsList with non-NULL id, similar to -set. However, it wouldn't *work* to use qemu_opts_set for the latter because qemu_opts_set uses fail_if_exists==1. So, for non-merge-lists QemuOptsList and non-NULL id, the semantics of qemu_opts_set (fail if the (QemuOptsList, id) pair already exists) are debatable. On the other hand, I would not expect qemu_opts_set to create a non-merge-lists QemuOpts with a single option; which it does, though. For this case of non-merge-lists QemuOptsList and NULL id, qemu_opts_set hardly adds value over qemu_opts_parse. It does skip some parsing and unescaping, but that's not needed when creating default network backends. So qemu_opts_set has warty behavior for non-merge-lists QemuOptsList if id is non-NULL, and it's mostly pointless if id is NULL. My solution to keeping the API as simple as possible is to limit qemu_opts_set to merge-lists QemuOptsList. For them, it's useful (we don't want comma-unescaping for -kernel) *and* has sane semantics. Network backend creation is switched to qemu_opts_parse. qemu_opts_set is now only used on merge-lists QemuOptsList... except in the testcase, which is changed to use a merge-list QemuOptsList. With this change we can also remove the id parameter. With the parameter always NULL, we know that qemu_opts_create cannot fail and can pass &error_abort to it. Signed-off-by: Paolo Bonzini --- include/qemu/option.h | 3 +-- softmmu/vl.c | 19 +++++++------------ tests/test-qemu-opts.c | 20 +++++++++++++++++--- util/qemu-option.c | 9 +++------ 4 files changed, 28 insertions(+), 23 deletions(-) diff --git a/include/qemu/option.h b/include/qemu/option.h index ac69352e0e..f73e0dc7d9 100644 --- a/include/qemu/option.h +++ b/include/qemu/option.h @@ -119,8 +119,7 @@ QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id, int fail_if_exists, Error **errp); void qemu_opts_reset(QemuOptsList *list); void qemu_opts_loc_restore(QemuOpts *opts); -bool qemu_opts_set(QemuOptsList *list, const char *id, - const char *name, const char *value, Error **errp); +bool qemu_opts_set(QemuOptsList *list, const char *name, const char *value, Error **errp); const char *qemu_opts_id(QemuOpts *opts); void qemu_opts_set_id(QemuOpts *opts, char *id); void qemu_opts_del(QemuOpts *opts); diff --git a/softmmu/vl.c b/softmmu/vl.c index 85b23d51be..5571f9ff75 100644 --- a/softmmu/vl.c +++ b/softmmu/vl.c @@ -3388,20 +3388,16 @@ void qemu_init(int argc, char **argv, char **envp) } break; case QEMU_OPTION_kernel: - qemu_opts_set(qemu_find_opts("machine"), NULL, "kernel", optarg, - &error_abort); + qemu_opts_set(qemu_find_opts("machine"), "kernel", optarg, &error_abort); break; case QEMU_OPTION_initrd: - qemu_opts_set(qemu_find_opts("machine"), NULL, "initrd", optarg, - &error_abort); + qemu_opts_set(qemu_find_opts("machine"), "initrd", optarg, &error_abort); break; case QEMU_OPTION_append: - qemu_opts_set(qemu_find_opts("machine"), NULL, "append", optarg, - &error_abort); + qemu_opts_set(qemu_find_opts("machine"), "append", optarg, &error_abort); break; case QEMU_OPTION_dtb: - qemu_opts_set(qemu_find_opts("machine"), NULL, "dtb", optarg, - &error_abort); + qemu_opts_set(qemu_find_opts("machine"), "dtb", optarg, &error_abort); break; case QEMU_OPTION_cdrom: drive_add(IF_DEFAULT, 2, optarg, CDROM_OPTS); @@ -3511,8 +3507,7 @@ void qemu_init(int argc, char **argv, char **envp) } break; case QEMU_OPTION_bios: - qemu_opts_set(qemu_find_opts("machine"), NULL, "firmware", optarg, - &error_abort); + qemu_opts_set(qemu_find_opts("machine"), "firmware", optarg, &error_abort); break; case QEMU_OPTION_singlestep: singlestep = 1; @@ -4395,9 +4390,9 @@ void qemu_init(int argc, char **argv, char **envp) if (default_net) { QemuOptsList *net = qemu_find_opts("net"); - qemu_opts_set(net, NULL, "type", "nic", &error_abort); + qemu_opts_parse(net, "nic", true, &error_abort); #ifdef CONFIG_SLIRP - qemu_opts_set(net, NULL, "type", "user", &error_abort); + qemu_opts_parse(net, "user", true, &error_abort); #endif } diff --git a/tests/test-qemu-opts.c b/tests/test-qemu-opts.c index 297ffe79dd..2aab831d10 100644 --- a/tests/test-qemu-opts.c +++ b/tests/test-qemu-opts.c @@ -84,11 +84,25 @@ static QemuOptsList opts_list_03 = { }, }; +static QemuOptsList opts_list_04 = { + .name = "opts_list_04", + .head = QTAILQ_HEAD_INITIALIZER(opts_list_04.head), + .merge_lists = true, + .desc = { + { + .name = "str3", + .type = QEMU_OPT_STRING, + }, + { /* end of list */ } + }, +}; + static void register_opts(void) { qemu_add_opts(&opts_list_01); qemu_add_opts(&opts_list_02); qemu_add_opts(&opts_list_03); + qemu_add_opts(&opts_list_04); } static void test_find_unknown_opts(void) @@ -402,17 +416,17 @@ static void test_qemu_opts_set(void) QemuOpts *opts; const char *opt; - list = qemu_find_opts("opts_list_01"); + list = qemu_find_opts("opts_list_04"); g_assert(list != NULL); g_assert(QTAILQ_EMPTY(&list->head)); - g_assert_cmpstr(list->name, ==, "opts_list_01"); + g_assert_cmpstr(list->name, ==, "opts_list_04"); /* should not find anything at this point */ opts = qemu_opts_find(list, NULL); g_assert(opts == NULL); /* implicitly create opts and set str3 value */ - qemu_opts_set(list, NULL, "str3", "value", &error_abort); + qemu_opts_set(list, "str3", "value", &error_abort); g_assert(!QTAILQ_EMPTY(&list->head)); /* get the just created opts */ diff --git a/util/qemu-option.c b/util/qemu-option.c index acefbc23fa..25792159ba 100644 --- a/util/qemu-option.c +++ b/util/qemu-option.c @@ -670,15 +670,12 @@ void qemu_opts_loc_restore(QemuOpts *opts) loc_restore(&opts->loc); } -bool qemu_opts_set(QemuOptsList *list, const char *id, - const char *name, const char *value, Error **errp) +bool qemu_opts_set(QemuOptsList *list, const char *name, const char *value, Error **errp) { QemuOpts *opts; - opts = qemu_opts_create(list, id, 1, errp); - if (!opts) { - return false; - } + assert(list->merge_lists); + opts = qemu_opts_create(list, NULL, 0, &error_abort); return qemu_opt_set(opts, name, value, errp); }