| Message ID | 20201109133931.979563-4-pbonzini@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Deprecate or forbid crazy QemuOpts cases | expand |
Paolo Bonzini <pbonzini@redhat.com> writes: > qemu_opts_set is used to create default network backends and to > parse sugar options -kernel, -initrd, -append, -bios and -dtb. > Switch the former to qemu_opts_parse, so that qemu_opts_set > is now only used on merge-lists QemuOptsList (for which it makes > the most sense indeed)... except in the testcase, which is > changed to use a merge-list QemuOptsList. > > With this change we can 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 <pbonzini@redhat.com> > --- > include/qemu/option.h | 3 +-- > softmmu/vl.c | 19 +++++++------------ > tests/test-qemu-opts.c | 24 +++++++++++++++++++++--- > util/qemu-option.c | 9 +++------ > 4 files changed, 32 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); Long line. Please break before Error. > 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 a71164494e..65607fe55e 100644 > --- a/softmmu/vl.c > +++ b/softmmu/vl.c > @@ -3107,20 +3107,16 @@ 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); > @@ -3230,8 +3226,7 @@ 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; Long lines. Please keep the line breaks. > @@ -4258,9 +4253,9 @@ 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 > } > Looks safe to me, but I don't quite get why you switch to qemu_opts_parse(). The commit message explains it is "so that qemu_opts_set is now only used on merge-lists QemuOptsList (for which it makes the most sense indeed)..." Is there anything wrong with using ot on non-merge-lists QemuOptsList? Am I missing something? > diff --git a/tests/test-qemu-opts.c b/tests/test-qemu-opts.c > index 297ffe79dd..322b32871b 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 +416,21 @@ 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", "first_value", &error_abort); This part the commit message mentions. > + g_assert(!QTAILQ_EMPTY(&list->head)); > + > + /* set it again */ > + qemu_opts_set(list, "str3", "value", &error_abort); > g_assert(!QTAILQ_EMPTY(&list->head)); This one not. What are you trying to accomplish? > > /* get the just created opts */ > diff --git a/util/qemu-option.c b/util/qemu-option.c > index 59be4f9d21..c88e159f18 100644 > --- a/util/qemu-option.c > +++ b/util/qemu-option.c > @@ -665,15 +665,12 @@ 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) Long line. Please break before Error. > { > 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); > } Yes, qemu_opts_create() can fail only if its second paramter is non-null, or its thirs paramter is non-zero. I can see quite a few such calls. Could be simplified with a wrapper that takes just the first parameter and can't fail. Not now. Just enough confusion on my part to withhold my R-by for now.
On 09/11/20 16:55, Markus Armbruster wrote: >> 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 >> } >> > Looks safe to me, but I don't quite get why you switch to > qemu_opts_parse(). The commit message explains it is "so that > qemu_opts_set is now only used on merge-lists QemuOptsList (for which it > makes the most sense indeed)..." Is there anything wrong with using ot > on non-merge-lists QemuOptsList? I would *expect* a function named qemu_opts_set to do two things: 1. setting an option in a merge-lists QemuOptsList, such as -kernel. This is indeed what we mostly use qemu_opts_set for. 2. setting an option in a non-merge-lists QemuOptsList with non-NULL id, similar to -set. QEMU does not use qemu_opts_set for the latter (see qemu_set_option) because it wants to use qemu_opts_find rather than qemu_opts_create. In fact 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, it is debatable that qemu_opts_set fails if the (QemuOptsList, id) pair already exists 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. This leads us directly to: -> For 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 its two call sites don't really care. 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. >> + g_assert(!QTAILQ_EMPTY(&list->head)); >> + >> + /* set it again */ >> + qemu_opts_set(list, "str3", "value", &error_abort); >> g_assert(!QTAILQ_EMPTY(&list->head)); > > This one not. > > What are you trying to accomplish? Improve the testcase, though I should have mentioned it in the commit message. Basically emulating "-kernel bc -kernel def". Paolo
Paolo Bonzini <pbonzini@redhat.com> writes: > On 09/11/20 16:55, Markus Armbruster wrote: >>> 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 >>> } >>> >> Looks safe to me, but I don't quite get why you switch to >> qemu_opts_parse(). The commit message explains it is "so that >> qemu_opts_set is now only used on merge-lists QemuOptsList (for which it >> makes the most sense indeed)..." Is there anything wrong with using ot >> on non-merge-lists QemuOptsList? > > I would *expect* a function named qemu_opts_set to do two things: > > 1. setting an option in a merge-lists QemuOptsList, such as -kernel. > > This is indeed what we mostly use qemu_opts_set for. > > > 2. setting an option in a non-merge-lists QemuOptsList with non-NULL > id, similar to -set. > > QEMU does not use qemu_opts_set for the latter (see qemu_set_option) > because it wants to use qemu_opts_find rather than qemu_opts_create. > In fact 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, it is > debatable that qemu_opts_set fails if the (QemuOptsList, id) > pair already exists > > > 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. > This leads us directly to: > > -> For 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 its two call sites don't really care. > > 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. Okay, makes sense. Do you think working (some of) this into commit message would be worth your while? >>> + g_assert(!QTAILQ_EMPTY(&list->head)); >>> + >>> + /* set it again */ >>> + qemu_opts_set(list, "str3", "value", &error_abort); >>> g_assert(!QTAILQ_EMPTY(&list->head)); >> This one not. >> What are you trying to accomplish? > > Improve the testcase, though I should have mentioned it in the commit > message. Basically emulating "-kernel bc -kernel def". Worth testing. But the case "-kernel bc" is also worth testing. test_qemu_opts_get() tests both: /* haven't set anything to str2 yet */ opt = qemu_opt_get(opts, "str2"); g_assert(opt == NULL); qemu_opt_set(opts, "str2", "value", &error_abort); /* now we have set str2, should know about it */ opt = qemu_opt_get(opts, "str2"); g_assert_cmpstr(opt, ==, "value"); qemu_opt_set(opts, "str2", "value2", &error_abort); /* having reset the value, the returned should be the reset one */ opt = qemu_opt_get(opts, "str2"); g_assert_cmpstr(opt, ==, "value2"); I'm okay with not improving the test in this patch, or with strictly extending coverage, preferably in a separate patch that goes before this one.
On 09/11/20 19:52, Markus Armbruster wrote: > Do you think working (some of) this into commit message would be worth > your while? Easy and does not require a respin, so yes. >> Improve the testcase, though I should have mentioned it in the commit >> message. Basically emulating "-kernel bc -kernel def". > Worth testing. But the case "-kernel bc" is also worth testing. > test_qemu_opts_get() tests both: > > /* haven't set anything to str2 yet */ > opt = qemu_opt_get(opts, "str2"); > g_assert(opt == NULL); > > qemu_opt_set(opts, "str2", "value", &error_abort); > > /* now we have set str2, should know about it */ > opt = qemu_opt_get(opts, "str2"); > g_assert_cmpstr(opt, ==, "value"); > > qemu_opt_set(opts, "str2", "value2", &error_abort); > > /* having reset the value, the returned should be the reset one */ > opt = qemu_opt_get(opts, "str2"); > g_assert_cmpstr(opt, ==, "value2"); Note opt_set vs. opts_set though. > I'm okay with not improving the test in this patch, or with strictly > extending coverage, preferably in a separate patch that goes before this > one. > Ok, I'll just drop the testcase change for now. Paolo
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 a71164494e..65607fe55e 100644 --- a/softmmu/vl.c +++ b/softmmu/vl.c @@ -3107,20 +3107,16 @@ 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); @@ -3230,8 +3226,7 @@ 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; @@ -4258,9 +4253,9 @@ 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..322b32871b 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 +416,21 @@ 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", "first_value", &error_abort); + g_assert(!QTAILQ_EMPTY(&list->head)); + + /* set it again */ + 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 59be4f9d21..c88e159f18 100644 --- a/util/qemu-option.c +++ b/util/qemu-option.c @@ -665,15 +665,12 @@ 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); }
qemu_opts_set is used to create default network backends and to parse sugar options -kernel, -initrd, -append, -bios and -dtb. Switch the former to qemu_opts_parse, so that qemu_opts_set is now only used on merge-lists QemuOptsList (for which it makes the most sense indeed)... except in the testcase, which is changed to use a merge-list QemuOptsList. With this change we can 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 <pbonzini@redhat.com> --- include/qemu/option.h | 3 +-- softmmu/vl.c | 19 +++++++------------ tests/test-qemu-opts.c | 24 +++++++++++++++++++++--- util/qemu-option.c | 9 +++------ 4 files changed, 32 insertions(+), 23 deletions(-)