* Dr. David Alan Gilbert (dgilbert@redhat.com) wrote:
> * Peter Xu (peterx@redhat.com) wrote:
> > v2:
>
> Queued
Hi Peter,
I've had to unqueue most of this; it doesn't like building on 32bit.
I fixed up the trace_ stuff easily (_del can take a void*, add just
needs to use PRIX64) but there are other places where it doesn't like
the casting from pointers to uint64_t's etc.
I've kept the first couple of commits.
Dave
> > - add r-bs for Dave
> > - add patch "migration: Properly destroy variables on incoming side" as patch 1
> > - destroy page_request_mutex in migration_incoming_state_destroy() too [Dave]
> > - use WITH_QEMU_LOCK_GUARD in two places where we can [Dave]
> >
> > We've seen conditional guest hangs on destination VM after postcopy recovered.
> > However the hang will resolve itself after a few minutes.
> >
> > The problem is: after a postcopy recovery, the prioritized postcopy queue on
> > the source VM is actually missing. So all the faulted threads before the
> > postcopy recovery happened will keep halted until (accidentally) the page got
> > copied by the background precopy migration stream.
> >
> > The solution is to also refresh this information after postcopy recovery. To
> > achieve this, we need to maintain a list of faulted addresses on the
> > destination node, so that we can resend the list when necessary. This work is
> > done via patch 2-5.
> >
> > With that, the last thing we need to do is to send this extra information to
> > source VM after recovered. Very luckily, this synchronization can be
> > "emulated" by sending a bunch of page requests (although these pages have been
> > sent previously!) to source VM just like when we've got a page fault. Even in
> > the 1st version of the postcopy code we'll handle duplicated pages well. So
> > this fix does not even need a new capability bit and it'll work smoothly on old
> > QEMUs when we migrate from them to the new QEMUs.
> >
> > Please review, thanks.
> >
> > Peter Xu (6):
> > migration: Properly destroy variables on incoming side
> > migration: Rework migrate_send_rp_req_pages() function
> > migration: Pass incoming state into qemu_ufd_copy_ioctl()
> > migration: Introduce migrate_send_rp_message_req_pages()
> > migration: Maintain postcopy faulted addresses
> > migration: Sync requested pages after postcopy recovery
> >
> > migration/migration.c | 79 +++++++++++++++++++++++++++++++++++-----
> > migration/migration.h | 23 +++++++++++-
> > migration/postcopy-ram.c | 46 ++++++++++-------------
> > migration/savevm.c | 57 +++++++++++++++++++++++++++++
> > migration/trace-events | 3 ++
> > 5 files changed, 171 insertions(+), 37 deletions(-)
> >
> > --
> > 2.26.2
> >
> >
> >
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK