| Message ID | 20200304172748.15338-1-imammedo@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [for-5.0] vl.c: fix migration failure for 3.1 and older machine types | expand |
Dne 04. 03. 20 v 18:27 Igor Mammedov napsal(a): > Migration from QEMU(v4.0) fails when using 3.1 or older machine > type. For example if one attempts to migrate > QEMU-2.12 started as > qemu-system-ppc64 -nodefaults -M pseries-2.12 -m 4096 -mem-path /tmp/ > to current master, it will fail with > qemu-system-ppc64: Unknown ramblock "ppc_spapr.ram", cannot accept migration > qemu-system-ppc64: error while loading state for instance 0x0 of device 'ram' > qemu-system-ppc64: load of migration failed: Invalid argument > > Caused by 900c0ba373 commit which switches main RAM allocation to > memory backends and the fact in 3.1 and older QEMU, backends used > full[***] QOM path as memory region name instead of backend's name. > That was changed after 3.1 to use prefix-less names by default > (fa0cb34d22) for new machine types. > *** effectively makes main RAM memory region names defined by > MachineClass::default_ram_id being altered with '/objects/' prefix > and therefore migration fails as old QEMU sends prefix-less > name while new QEMU expects name with prefix when using 3.1 and > older machine types. > > Fix it by forcing implicit[1] memory backend to always use > prefix-less names for its memory region by setting > 'x-use-canonical-path-for-ramblock-id' > property to false. > > 1) i.e. memory backend created by compat glue which maps > -m/-mem-path/-mem-prealloc/default RAM size into > appropriate backend type/options to match old CLI format. > > Fixes: 900c0ba373 > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > Reported-by: Lukáš Doktor <ldoktor@redhat.com> > --- > CC: ldoktor@redhat.com > CC: marcandre.lureau@redhat.com > CC: dgilbert@redhat.com > --- > softmmu/vl.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/softmmu/vl.c b/softmmu/vl.c > index 5549f4b619..1101b1cb41 100644 > --- a/softmmu/vl.c > +++ b/softmmu/vl.c > @@ -2800,6 +2800,9 @@ static void create_default_memdev(MachineState *ms, const char *path) > object_property_set_int(obj, ms->ram_size, "size", &error_fatal); > object_property_add_child(object_get_objects_root(), mc->default_ram_id, > obj, &error_fatal); > + /* Ensure backend's memory region name is equal to mc->default_ram_id */ > + object_property_set_bool(obj, false, "x-use-canonical-path-for-ramblock-id", > + &error_fatal); > user_creatable_complete(USER_CREATABLE(obj), &error_fatal); > object_unref(obj); > object_property_set_str(OBJECT(ms), mc->default_ram_id, "memory-backend", > Tested-by: Lukáš Doktor <ldoktor@redhat.com> I can't say anything about the code, but functional-wise it addresses the issue and fixes post_copy hugepages migration in my mini-CI (variants 2.10, 2.12, 3.0, 3.1, 4.0 -> master and vice-versa are failing with master and passing with this patch). Regards, Lukáš
Hi On Wed, Mar 4, 2020 at 6:28 PM Igor Mammedov <imammedo@redhat.com> wrote: > > Migration from QEMU(v4.0) fails when using 3.1 or older machine > type. For example if one attempts to migrate > QEMU-2.12 started as > qemu-system-ppc64 -nodefaults -M pseries-2.12 -m 4096 -mem-path /tmp/ > to current master, it will fail with > qemu-system-ppc64: Unknown ramblock "ppc_spapr.ram", cannot accept migration > qemu-system-ppc64: error while loading state for instance 0x0 of device 'ram' > qemu-system-ppc64: load of migration failed: Invalid argument > > Caused by 900c0ba373 commit which switches main RAM allocation to > memory backends and the fact in 3.1 and older QEMU, backends used > full[***] QOM path as memory region name instead of backend's name. > That was changed after 3.1 to use prefix-less names by default > (fa0cb34d22) for new machine types. > *** effectively makes main RAM memory region names defined by > MachineClass::default_ram_id being altered with '/objects/' prefix > and therefore migration fails as old QEMU sends prefix-less > name while new QEMU expects name with prefix when using 3.1 and > older machine types. > > Fix it by forcing implicit[1] memory backend to always use > prefix-less names for its memory region by setting > 'x-use-canonical-path-for-ramblock-id' > property to false. ahah, ok. If main RAM allocation was always using prefix-less name, then that should be good enough: Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> > > 1) i.e. memory backend created by compat glue which maps > -m/-mem-path/-mem-prealloc/default RAM size into > appropriate backend type/options to match old CLI format. > > Fixes: 900c0ba373 > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > Reported-by: Lukáš Doktor <ldoktor@redhat.com> > --- > CC: ldoktor@redhat.com > CC: marcandre.lureau@redhat.com > CC: dgilbert@redhat.com > --- > softmmu/vl.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/softmmu/vl.c b/softmmu/vl.c > index 5549f4b619..1101b1cb41 100644 > --- a/softmmu/vl.c > +++ b/softmmu/vl.c > @@ -2800,6 +2800,9 @@ static void create_default_memdev(MachineState *ms, const char *path) > object_property_set_int(obj, ms->ram_size, "size", &error_fatal); > object_property_add_child(object_get_objects_root(), mc->default_ram_id, > obj, &error_fatal); > + /* Ensure backend's memory region name is equal to mc->default_ram_id */ > + object_property_set_bool(obj, false, "x-use-canonical-path-for-ramblock-id", > + &error_fatal); > user_creatable_complete(USER_CREATABLE(obj), &error_fatal); > object_unref(obj); > object_property_set_str(OBJECT(ms), mc->default_ram_id, "memory-backend", > -- > 2.18.1 > >
On Wed, 4 Mar 2020 12:27:48 -0500 Igor Mammedov <imammedo@redhat.com> wrote: > Migration from QEMU(v4.0) fails when using 3.1 or older machine > type. For example if one attempts to migrate > QEMU-2.12 started as > qemu-system-ppc64 -nodefaults -M pseries-2.12 -m 4096 -mem-path /tmp/ > to current master, it will fail with > qemu-system-ppc64: Unknown ramblock "ppc_spapr.ram", cannot accept migration > qemu-system-ppc64: error while loading state for instance 0x0 of device 'ram' > qemu-system-ppc64: load of migration failed: Invalid argument > > Caused by 900c0ba373 commit which switches main RAM allocation to > memory backends and the fact in 3.1 and older QEMU, backends used > full[***] QOM path as memory region name instead of backend's name. > That was changed after 3.1 to use prefix-less names by default > (fa0cb34d22) for new machine types. > *** effectively makes main RAM memory region names defined by > MachineClass::default_ram_id being altered with '/objects/' prefix > and therefore migration fails as old QEMU sends prefix-less > name while new QEMU expects name with prefix when using 3.1 and > older machine types. > > Fix it by forcing implicit[1] memory backend to always use > prefix-less names for its memory region by setting > 'x-use-canonical-path-for-ramblock-id' > property to false. > > 1) i.e. memory backend created by compat glue which maps > -m/-mem-path/-mem-prealloc/default RAM size into > appropriate backend type/options to match old CLI format. > > Fixes: 900c0ba373 > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > Reported-by: Lukáš Doktor <ldoktor@redhat.com> ping, so we don't forget to merge it > --- > CC: ldoktor@redhat.com > CC: marcandre.lureau@redhat.com > CC: dgilbert@redhat.com > --- > softmmu/vl.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/softmmu/vl.c b/softmmu/vl.c > index 5549f4b619..1101b1cb41 100644 > --- a/softmmu/vl.c > +++ b/softmmu/vl.c > @@ -2800,6 +2800,9 @@ static void create_default_memdev(MachineState *ms, const char *path) > object_property_set_int(obj, ms->ram_size, "size", &error_fatal); > object_property_add_child(object_get_objects_root(), mc->default_ram_id, > obj, &error_fatal); > + /* Ensure backend's memory region name is equal to mc->default_ram_id */ > + object_property_set_bool(obj, false, "x-use-canonical-path-for-ramblock-id", > + &error_fatal); > user_creatable_complete(USER_CREATABLE(obj), &error_fatal); > object_unref(obj); > object_property_set_str(OBJECT(ms), mc->default_ram_id, "memory-backend",
* Igor Mammedov (imammedo@redhat.com) wrote: > On Wed, 4 Mar 2020 12:27:48 -0500 > Igor Mammedov <imammedo@redhat.com> wrote: > > > Migration from QEMU(v4.0) fails when using 3.1 or older machine > > type. For example if one attempts to migrate > > QEMU-2.12 started as > > qemu-system-ppc64 -nodefaults -M pseries-2.12 -m 4096 -mem-path /tmp/ > > to current master, it will fail with > > qemu-system-ppc64: Unknown ramblock "ppc_spapr.ram", cannot accept migration > > qemu-system-ppc64: error while loading state for instance 0x0 of device 'ram' > > qemu-system-ppc64: load of migration failed: Invalid argument > > > > Caused by 900c0ba373 commit which switches main RAM allocation to > > memory backends and the fact in 3.1 and older QEMU, backends used > > full[***] QOM path as memory region name instead of backend's name. > > That was changed after 3.1 to use prefix-less names by default > > (fa0cb34d22) for new machine types. > > *** effectively makes main RAM memory region names defined by > > MachineClass::default_ram_id being altered with '/objects/' prefix > > and therefore migration fails as old QEMU sends prefix-less > > name while new QEMU expects name with prefix when using 3.1 and > > older machine types. > > > > Fix it by forcing implicit[1] memory backend to always use > > prefix-less names for its memory region by setting > > 'x-use-canonical-path-for-ramblock-id' > > property to false. > > > > 1) i.e. memory backend created by compat glue which maps > > -m/-mem-path/-mem-prealloc/default RAM size into > > appropriate backend type/options to match old CLI format. > > > > Fixes: 900c0ba373 > > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > > Reported-by: Lukáš Doktor <ldoktor@redhat.com> > > > ping, > > so we don't forget to merge it I'm queueing this. > > --- > > CC: ldoktor@redhat.com > > CC: marcandre.lureau@redhat.com > > CC: dgilbert@redhat.com > > --- > > softmmu/vl.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/softmmu/vl.c b/softmmu/vl.c > > index 5549f4b619..1101b1cb41 100644 > > --- a/softmmu/vl.c > > +++ b/softmmu/vl.c > > @@ -2800,6 +2800,9 @@ static void create_default_memdev(MachineState *ms, const char *path) > > object_property_set_int(obj, ms->ram_size, "size", &error_fatal); > > object_property_add_child(object_get_objects_root(), mc->default_ram_id, > > obj, &error_fatal); > > + /* Ensure backend's memory region name is equal to mc->default_ram_id */ > > + object_property_set_bool(obj, false, "x-use-canonical-path-for-ramblock-id", > > + &error_fatal); > > user_creatable_complete(USER_CREATABLE(obj), &error_fatal); > > object_unref(obj); > > object_property_set_str(OBJECT(ms), mc->default_ram_id, "memory-backend", > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
diff --git a/softmmu/vl.c b/softmmu/vl.c index 5549f4b619..1101b1cb41 100644 --- a/softmmu/vl.c +++ b/softmmu/vl.c @@ -2800,6 +2800,9 @@ static void create_default_memdev(MachineState *ms, const char *path) object_property_set_int(obj, ms->ram_size, "size", &error_fatal); object_property_add_child(object_get_objects_root(), mc->default_ram_id, obj, &error_fatal); + /* Ensure backend's memory region name is equal to mc->default_ram_id */ + object_property_set_bool(obj, false, "x-use-canonical-path-for-ramblock-id", + &error_fatal); user_creatable_complete(USER_CREATABLE(obj), &error_fatal); object_unref(obj); object_property_set_str(OBJECT(ms), mc->default_ram_id, "memory-backend",
Migration from QEMU(v4.0) fails when using 3.1 or older machine type. For example if one attempts to migrate QEMU-2.12 started as qemu-system-ppc64 -nodefaults -M pseries-2.12 -m 4096 -mem-path /tmp/ to current master, it will fail with qemu-system-ppc64: Unknown ramblock "ppc_spapr.ram", cannot accept migration qemu-system-ppc64: error while loading state for instance 0x0 of device 'ram' qemu-system-ppc64: load of migration failed: Invalid argument Caused by 900c0ba373 commit which switches main RAM allocation to memory backends and the fact in 3.1 and older QEMU, backends used full[***] QOM path as memory region name instead of backend's name. That was changed after 3.1 to use prefix-less names by default (fa0cb34d22) for new machine types. *** effectively makes main RAM memory region names defined by MachineClass::default_ram_id being altered with '/objects/' prefix and therefore migration fails as old QEMU sends prefix-less name while new QEMU expects name with prefix when using 3.1 and older machine types. Fix it by forcing implicit[1] memory backend to always use prefix-less names for its memory region by setting 'x-use-canonical-path-for-ramblock-id' property to false. 1) i.e. memory backend created by compat glue which maps -m/-mem-path/-mem-prealloc/default RAM size into appropriate backend type/options to match old CLI format. Fixes: 900c0ba373 Signed-off-by: Igor Mammedov <imammedo@redhat.com> Reported-by: Lukáš Doktor <ldoktor@redhat.com> --- CC: ldoktor@redhat.com CC: marcandre.lureau@redhat.com CC: dgilbert@redhat.com --- softmmu/vl.c | 3 +++ 1 file changed, 3 insertions(+)