On Tue, 30 May 2017 16:18:52 +1000 David Gibson <da...@gibson.dropbear.id.au> wrote:
> On Tue, May 30, 2017 at 01:14:16AM +0200, Greg Kurz wrote:
> > On Fri, 26 May 2017 15:23:14 +1000
> > David Gibson <da...@gibson.dropbear.id.au> wrote:
> >
> > [...]
> > >
> > >
> > > Changes since v3:
> > > * Backwards compatible -cpu handling now removes compat= option from
> > > options passed on to the cpu, so it doesn't trigger further warnings
> >
> > This seems to also have another interesting effect.
> >
> > getset_compat_deprecated() could be called either during CPU realization
> > from:
> >
> > object_property_parse()
> > {
> > Visitor *v = string_input_visitor_new(string);
> > object_property_set(obj, v, name, errp);
> > ...
> > }
> >
> > or during a QOM set operation from:
> >
> > void object_property_set_qobject(Object *obj, QObject *value,
> > const char *name, Error **errp)
> > {
> > Visitor *v;
> >
> > v = qobject_input_visitor_new(value);
> > object_property_set(obj, v, name, errp);
> > ...
> > }
> >
> > or similarly during a QOM get operation with a QObject output visitor.
> >
> > The realization path no longer exists with patch 2, so you don't need
> > to implement a null string input visitor anymore.
>
> s/patch 2/patch 3/?
>
Yes indeed, sorry :)
> Is that true though? It shouldn't get called through that path in
> practice, because we strip the compat property from the cpu object
> properties. But it could get called if either a) the user explicitly
> creates a cpu object with -device CPU,compat=whatever or b) if the
Unless I'm missing something, properties of the CPU objects aren't
exposed by CPU devices:
qemu-system-ppc64 -machine pseries \
-device POWER8_v2.0-spapr-cpu-core,help
POWER8_v2.0-spapr-cpu-core.core-id=int
POWER8_v2.0-spapr-cpu-core.node-id=int32
POWER8_v2.0-spapr-cpu-core.nr-threads=int
and creation of CPU objects with -object isn't possible either since
they don't inherit from the TYPE_USER_CREATABLE class.
> user uses the compat= property with a machine type other than pseries.
>
But yes, it is still possible to go through the object_property_parse()
path with another machine type indeed.
> Of course the user *shouldn't* do either of those things, but
> providing a meaningful error if they do is pretty much the whole
> purpose of this getter/setter method.
>
All old non-pseries machine types already complain when started with
a POWER7 or newer CPU. Providing the extra error message looks weird:
qemu-system-ppc64 -machine ppce500 \
-cpu POWER7,compat=power6
qemu-system-ppc64: CPU 'compat' property is deprecated and has no effect;
use max-cpu-compat machine property instead
MMU model 983043 not supported by this machine.
but I guess it's better than crashing. :)
> >
> > This means that patch 1 is no longer needed if I get things right but
> > you probably want Markus to second that.
> >
> > > * Add a migration fix make cpu_synchronize_state() safe in post_load
> > > handlers, which in turn fixes a bug in 5/5.
> > > * A number of bugfixes and other tweaks suggested by feedback on v2.
> > >
> > > Changes since RFCv2:
> > > * Many patches dropped, since they're already merged
> > > * Rebased, fixed conflicts
> > > * Restored support for backwards migration (wasn't as complicated as
> > > I thought)
> > > * Updated final patch's description to more accurately reflect the
> > > logic
> > >
> > > Changes since RFCv1:
> > > * Change CAS logic to prefer compatibility modes over raw mode
> > > * Simplified by giving up on half-hearted attempts to maintain
> > > backwards migration
> > > * Folded migration stream changes into a single patch
> > > * Removed some preliminary patches which are already merged
> > >
> > > David Gibson (4):
> > > migration: Mark CPU states dirty before incoming migration/loadvm
> > > pseries: Move CPU compatibility property to machine
> > > pseries: Reset CPU compatibility mode
> > > ppc: Rework CPU compatibility testing across migration
> > >
> > > Greg Kurz (1):
> > > qapi: add explicit null to string input and output visitors
> > >
> > > cpus.c | 9 ++++
> > > hw/ppc/spapr.c | 8 +++-
> > > hw/ppc/spapr_cpu_core.c | 62 +++++++++++++++++++++-----
> > > hw/ppc/spapr_hcall.c | 8 ++--
> > > include/hw/ppc/spapr.h | 12 +++--
> > > include/sysemu/cpus.h | 1 +
> > > include/sysemu/hax.h | 1 +
> > > include/sysemu/hw_accel.h | 10 +++++
> > > include/sysemu/kvm.h | 1 +
> > > kvm-all.c | 10 +++++
> > > migration/savevm.c | 2 +
> > > qapi/string-input-visitor.c | 11 +++++
> > > qapi/string-output-visitor.c | 14 ++++++
> > > target/i386/hax-all.c | 10 +++++
> > > target/ppc/compat.c | 102
> > > +++++++++++++++++++++++++++++++++++++++++++
> > > target/ppc/cpu.h | 5 ++-
> > > target/ppc/machine.c | 72 ++++++++++++++++++++++++++++--
> > > target/ppc/translate_init.c | 86 +++++++++++-------------------------
> > > 18 files changed, 340 insertions(+), 84 deletions(-)
> > >
> >
>
>
>
pgpHHnGfGcQgJ.pgp
Description: OpenPGP digital signature
