Re: [Qemu-devel] [PATCH v3 2/2] monitor: fix object_del for command-line-created objects
Quoting Markus Armbruster (2016-12-12 09:53:20) > Michael Rothwrites: > > > Currently objects specified on the command-line are only partially > > cleaned up when 'object_del' is issued in either HMP or QMP: the > > object itself is fully finalized, but the QemuOpts are not removed. > > This results in the following behavior: > > > > x86_64-softmmu/qemu-system-x86_64 -monitor stdio \ > > -object memory-backend-ram,id=ram1,size=256M > > > > QEMU 2.7.91 monitor - type 'help' for more information > > (qemu) object_del ram1 > > (qemu) object_del ram1 > > object 'ram1' not found > > (qemu) object_add memory-backend-ram,id=ram1,size=256M > > Duplicate ID 'ram1' for object > > Try "help object_add" for more information > > > > which can be an issue for use-cases like memory hotplug. > > > > This happens on the HMP side because hmp_object_add() attempts to > > create a temporary QemuOpts entry with ID 'ram1', which ends up > > conflicting with the command-line-created entry, since it was never > > cleaned up during the previous hmp_object_del() call. > > > > We address this by adding a check in user_creatable_del(), which > > is called by both qmp_object_del() and hmp_object_del() to handle > > the actual object cleanup, to determine whether an option group entry > > matching the object's ID is present and removing it if it is. > > > > Note that qmp_object_add() never attempts to create a temporary > > QemuOpts entry, so it does not encounter the duplicate ID error, > > which is why this isn't generally visible in libvirt. > > > > Cc: "Dr. David Alan Gilbert" > > Cc: Markus Armbruster > > Cc: Eric Blake > > Cc: Daniel Berrange > > Cc: qemu-sta...@nongnu.org > > Signed-off-by: Michael Roth > > Reviewed-by: Daniel P. Berrange > > --- > > qom/object_interfaces.c| 7 +++ > > tests/check-qom-proplist.c | 4 ++-- > > 2 files changed, 9 insertions(+), 2 deletions(-) > > > > diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c > > index ded4d84..b462a74 100644 > > --- a/qom/object_interfaces.c > > +++ b/qom/object_interfaces.c > > @@ -5,6 +5,7 @@ > > #include "qapi-visit.h" > > #include "qapi/qobject-output-visitor.h" > > #include "qapi/opts-visitor.h" > > +#include "qemu/config-file.h" > > > > void user_creatable_complete(Object *obj, Error **errp) > > { > > @@ -209,6 +210,12 @@ void user_creatable_del(const char *id, Error **errp) > > error_setg(errp, "object '%s' is in use, can not be deleted", id); > > return; > > } > > + > > +/* if object was defined on the command-line, remove its corresponding > > + * option group entry > > + */ > > Consider adding wings to both ends of multi-line comments. > > > +qemu_opts_del(qemu_opts_find(qemu_find_opts_err("object", NULL), id)); > > qemu_find_opts_err() can't fail. If it did, qemu_opts_find() would > crash. Okay. > > Elsewhere, we use qemu_opts_find(qemu_find_opts(NAME)), which would > report an error to stderr / monitor before crashing. Also okay. > > Perhaps the cleanest (but not the tersest) way to skin this cat: > qemu_opts_find(qemu_find_opts_err(_abort)). > > Your choice. > > > + > > object_unparent(obj); > > } > > > > diff --git a/tests/check-qom-proplist.c b/tests/check-qom-proplist.c > > index e3f56ca..c5d4b60 100644 > > --- a/tests/check-qom-proplist.c > > +++ b/tests/check-qom-proplist.c > > @@ -437,9 +437,9 @@ static void test_dummy_createcmdl(void) > > * check for this in user_creatable_del() and remove the QemuOpts if > > * it is present. > > * > > - * FIXME: add an assert to verify that the QemuOpts is cleaned up > > - * once the corresponding cleanup code is added. > > + * The below check ensures this works as expected. > > */ > > +g_assert(qemu_opts_find(_object_opts, "dev0") == NULL); > > There's also g_assert_null(), which could result in a more helpful > message when the assertion fails. Your choice. Thanks for the suggestions; I've incorporated all of them into v4. > > > } > > > > static void test_dummy_badenum(void) >
Re: [Qemu-devel] [PATCH v3 2/2] monitor: fix object_del for command-line-created objects
Michael Rothwrites: > Currently objects specified on the command-line are only partially > cleaned up when 'object_del' is issued in either HMP or QMP: the > object itself is fully finalized, but the QemuOpts are not removed. > This results in the following behavior: > > x86_64-softmmu/qemu-system-x86_64 -monitor stdio \ > -object memory-backend-ram,id=ram1,size=256M > > QEMU 2.7.91 monitor - type 'help' for more information > (qemu) object_del ram1 > (qemu) object_del ram1 > object 'ram1' not found > (qemu) object_add memory-backend-ram,id=ram1,size=256M > Duplicate ID 'ram1' for object > Try "help object_add" for more information > > which can be an issue for use-cases like memory hotplug. > > This happens on the HMP side because hmp_object_add() attempts to > create a temporary QemuOpts entry with ID 'ram1', which ends up > conflicting with the command-line-created entry, since it was never > cleaned up during the previous hmp_object_del() call. > > We address this by adding a check in user_creatable_del(), which > is called by both qmp_object_del() and hmp_object_del() to handle > the actual object cleanup, to determine whether an option group entry > matching the object's ID is present and removing it if it is. > > Note that qmp_object_add() never attempts to create a temporary > QemuOpts entry, so it does not encounter the duplicate ID error, > which is why this isn't generally visible in libvirt. > > Cc: "Dr. David Alan Gilbert" > Cc: Markus Armbruster > Cc: Eric Blake > Cc: Daniel Berrange > Cc: qemu-sta...@nongnu.org > Signed-off-by: Michael Roth > Reviewed-by: Daniel P. Berrange > --- > qom/object_interfaces.c| 7 +++ > tests/check-qom-proplist.c | 4 ++-- > 2 files changed, 9 insertions(+), 2 deletions(-) > > diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c > index ded4d84..b462a74 100644 > --- a/qom/object_interfaces.c > +++ b/qom/object_interfaces.c > @@ -5,6 +5,7 @@ > #include "qapi-visit.h" > #include "qapi/qobject-output-visitor.h" > #include "qapi/opts-visitor.h" > +#include "qemu/config-file.h" > > void user_creatable_complete(Object *obj, Error **errp) > { > @@ -209,6 +210,12 @@ void user_creatable_del(const char *id, Error **errp) > error_setg(errp, "object '%s' is in use, can not be deleted", id); > return; > } > + > +/* if object was defined on the command-line, remove its corresponding > + * option group entry > + */ Consider adding wings to both ends of multi-line comments. > +qemu_opts_del(qemu_opts_find(qemu_find_opts_err("object", NULL), id)); qemu_find_opts_err() can't fail. If it did, qemu_opts_find() would crash. Okay. Elsewhere, we use qemu_opts_find(qemu_find_opts(NAME)), which would report an error to stderr / monitor before crashing. Also okay. Perhaps the cleanest (but not the tersest) way to skin this cat: qemu_opts_find(qemu_find_opts_err(_abort)). Your choice. > + > object_unparent(obj); > } > > diff --git a/tests/check-qom-proplist.c b/tests/check-qom-proplist.c > index e3f56ca..c5d4b60 100644 > --- a/tests/check-qom-proplist.c > +++ b/tests/check-qom-proplist.c > @@ -437,9 +437,9 @@ static void test_dummy_createcmdl(void) > * check for this in user_creatable_del() and remove the QemuOpts if > * it is present. > * > - * FIXME: add an assert to verify that the QemuOpts is cleaned up > - * once the corresponding cleanup code is added. > + * The below check ensures this works as expected. > */ > +g_assert(qemu_opts_find(_object_opts, "dev0") == NULL); There's also g_assert_null(), which could result in a more helpful message when the assertion fails. Your choice. > } > > static void test_dummy_badenum(void)
[Qemu-devel] [PATCH v3 2/2] monitor: fix object_del for command-line-created objects
Currently objects specified on the command-line are only partially cleaned up when 'object_del' is issued in either HMP or QMP: the object itself is fully finalized, but the QemuOpts are not removed. This results in the following behavior: x86_64-softmmu/qemu-system-x86_64 -monitor stdio \ -object memory-backend-ram,id=ram1,size=256M QEMU 2.7.91 monitor - type 'help' for more information (qemu) object_del ram1 (qemu) object_del ram1 object 'ram1' not found (qemu) object_add memory-backend-ram,id=ram1,size=256M Duplicate ID 'ram1' for object Try "help object_add" for more information which can be an issue for use-cases like memory hotplug. This happens on the HMP side because hmp_object_add() attempts to create a temporary QemuOpts entry with ID 'ram1', which ends up conflicting with the command-line-created entry, since it was never cleaned up during the previous hmp_object_del() call. We address this by adding a check in user_creatable_del(), which is called by both qmp_object_del() and hmp_object_del() to handle the actual object cleanup, to determine whether an option group entry matching the object's ID is present and removing it if it is. Note that qmp_object_add() never attempts to create a temporary QemuOpts entry, so it does not encounter the duplicate ID error, which is why this isn't generally visible in libvirt. Cc: "Dr. David Alan Gilbert"Cc: Markus Armbruster Cc: Eric Blake Cc: Daniel Berrange Cc: qemu-sta...@nongnu.org Signed-off-by: Michael Roth Reviewed-by: Daniel P. Berrange --- qom/object_interfaces.c| 7 +++ tests/check-qom-proplist.c | 4 ++-- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c index ded4d84..b462a74 100644 --- a/qom/object_interfaces.c +++ b/qom/object_interfaces.c @@ -5,6 +5,7 @@ #include "qapi-visit.h" #include "qapi/qobject-output-visitor.h" #include "qapi/opts-visitor.h" +#include "qemu/config-file.h" void user_creatable_complete(Object *obj, Error **errp) { @@ -209,6 +210,12 @@ void user_creatable_del(const char *id, Error **errp) error_setg(errp, "object '%s' is in use, can not be deleted", id); return; } + +/* if object was defined on the command-line, remove its corresponding + * option group entry + */ +qemu_opts_del(qemu_opts_find(qemu_find_opts_err("object", NULL), id)); + object_unparent(obj); } diff --git a/tests/check-qom-proplist.c b/tests/check-qom-proplist.c index e3f56ca..c5d4b60 100644 --- a/tests/check-qom-proplist.c +++ b/tests/check-qom-proplist.c @@ -437,9 +437,9 @@ static void test_dummy_createcmdl(void) * check for this in user_creatable_del() and remove the QemuOpts if * it is present. * - * FIXME: add an assert to verify that the QemuOpts is cleaned up - * once the corresponding cleanup code is added. + * The below check ensures this works as expected. */ +g_assert(qemu_opts_find(_object_opts, "dev0") == NULL); } static void test_dummy_badenum(void) -- 1.9.1