On Thu, Aug 24, 2017 at 08:27:05PM +0100, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> > > Add a notifier chain for postcopy with a 'reason' flag > and an opportunity for a notifier member to return an error. > > Call it when enabling postcopy. > > This will initially used to enable devices to declare they're unable > to postcopy and later to notify of devices of stages within postcopy. > > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com> > --- > migration/postcopy-ram.c | 41 +++++++++++++++++++++++++++++++++++++++++ > migration/postcopy-ram.h | 26 ++++++++++++++++++++++++++ > vl.c | 2 ++ > 3 files changed, 69 insertions(+) > > diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c > index 640b72d86d..95007c00ef 100644 > --- a/migration/postcopy-ram.c > +++ b/migration/postcopy-ram.c > @@ -23,6 +23,8 @@ > #include "savevm.h" > #include "postcopy-ram.h" > #include "ram.h" > +#include "qapi/error.h" > +#include "qemu/notify.h" > #include "sysemu/sysemu.h" > #include "sysemu/balloon.h" > #include "qemu/error-report.h" > @@ -45,6 +47,38 @@ struct PostcopyDiscardState { > unsigned int nsentcmds; > }; > > +/* A notifier chain for postcopy > + * The notifier should return 0 if it's OK, or a > + * -errno on error. > + * The notifier should expect an Error ** as it's data
"PostcopyNotifyData *" but not "Error **"? Maybe we can just remove this block of comment since there is a similar one in the header below. Besides: Reviewed-by: Peter Xu <pet...@redhat.com> > + */ > +static NotifierWithReturnList postcopy_notifier_list; > + > +void postcopy_infrastructure_init(void) > +{ > + notifier_with_return_list_init(&postcopy_notifier_list); > +} > + > +void postcopy_add_notifier(NotifierWithReturn *nn) > +{ > + notifier_with_return_list_add(&postcopy_notifier_list, nn); > +} > + > +void postcopy_remove_notifier(NotifierWithReturn *n) > +{ > + notifier_with_return_remove(n); > +} > + > +int postcopy_notify(enum PostcopyNotifyReason reason, Error **errp) > +{ > + struct PostcopyNotifyData pnd; > + pnd.reason = reason; > + pnd.errp = errp; > + > + return notifier_with_return_list_notify(&postcopy_notifier_list, > + &pnd); > +} > + > /* Postcopy needs to detect accesses to pages that haven't yet been copied > * across, and efficiently map new pages in, the techniques for doing this > * are target OS specific. > @@ -133,6 +167,7 @@ bool postcopy_ram_supported_by_host(void) > struct uffdio_register reg_struct; > struct uffdio_range range_struct; > uint64_t feature_mask; > + Error *local_err = NULL; > > if (qemu_target_page_size() > pagesize) { > error_report("Target page size bigger than host page size"); > @@ -146,6 +181,12 @@ bool postcopy_ram_supported_by_host(void) > goto out; > } > > + /* Give devices a chance to object */ > + if (postcopy_notify(POSTCOPY_NOTIFY_PROBE, &local_err)) { > + error_report_err(local_err); > + goto out; > + } > + > /* Version and features check */ > if (!ufd_version_check(ufd)) { > goto out; > diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h > index 78a3591322..d688411674 100644 > --- a/migration/postcopy-ram.h > +++ b/migration/postcopy-ram.h > @@ -114,4 +114,30 @@ PostcopyState postcopy_state_get(void); > /* Set the state and return the old state */ > PostcopyState postcopy_state_set(PostcopyState new_state); > > +/* > + * To be called once at the start before any device initialisation > + */ > +void postcopy_infrastructure_init(void); > + > +/* Add a notifier to a list to be called when checking whether the devices > + * can support postcopy. > + * It's data is a *PostcopyNotifyData > + * It should return 0 if OK, or a negative value on failure. > + * On failure it must set the data->errp to an error. > + * > + */ > +enum PostcopyNotifyReason { > + POSTCOPY_NOTIFY_PROBE = 0, > +}; > + > +struct PostcopyNotifyData { > + enum PostcopyNotifyReason reason; > + Error **errp; > +}; > + > +void postcopy_add_notifier(NotifierWithReturn *nn); > +void postcopy_remove_notifier(NotifierWithReturn *n); > +/* Call the notifier list set by postcopy_add_start_notifier */ > +int postcopy_notify(enum PostcopyNotifyReason reason, Error **errp); > + > #endif > diff --git a/vl.c b/vl.c > index 8e247cc2a2..65dd9dc324 100644 > --- a/vl.c > +++ b/vl.c > @@ -95,6 +95,7 @@ int main(int argc, char **argv) > #include "audio/audio.h" > #include "sysemu/cpus.h" > #include "migration/colo.h" > +#include "migration/postcopy-ram.h" > #include "sysemu/kvm.h" > #include "sysemu/hax.h" > #include "qapi/qobject-input-visitor.h" > @@ -3082,6 +3083,7 @@ int main(int argc, char **argv, char **envp) > module_call_init(MODULE_INIT_OPTS); > > runstate_init(); > + postcopy_infrastructure_init(); > > if (qcrypto_init(&err) < 0) { > error_reportf_err(err, "cannot initialize crypto: "); > -- > 2.13.5 > -- Peter Xu