> From: Qemu-devel <qemu-devel- > bounces+yishaih=nvidia....@nongnu.org> On Behalf Of Juan Quintela > Sent: Monday, 3 October 2022 6:16 > To: qemu-devel@nongnu.org > Cc: Alex Williamson <alex.william...@redhat.com>; Eric Blake > <ebl...@redhat.com>; Stefan Hajnoczi <stefa...@redhat.com>; Fam > Zheng <f...@euphon.net>; qemu-s3...@nongnu.org; Cornelia Huck > <coh...@redhat.com>; Thomas Huth <th...@redhat.com>; Vladimir > Sementsov-Ogievskiy <vsement...@yandex-team.ru>; Laurent Vivier > <lviv...@redhat.com>; John Snow <js...@redhat.com>; Dr. David Alan > Gilbert <dgilb...@redhat.com>; Christian Borntraeger > <borntrae...@linux.ibm.com>; Halil Pasic <pa...@linux.ibm.com>; Juan > Quintela <quint...@redhat.com>; Paolo Bonzini <pbonz...@redhat.com>; > qemu-bl...@nongnu.org; Eric Farman <far...@linux.ibm.com>; Richard > Henderson <richard.hender...@linaro.org>; David Hildenbrand > <da...@redhat.com> > Subject: [RFC 0/7] migration patches for VFIO > > Hi > > VFIO migration has several requirements: > - the size of the state is only known when the guest is stopped
As was discussed in the conference call, I just sent a patch to the kernel mailing list to be able to get the state size in each state. See: https://patchwork.kernel.org/project/kvm/patch/20221020132109.112708-1-yish...@nvidia.com/ This can drop the need to stop the guest and ask for that data. So, I assume that you can drop some complexity and hacks from your RFC once you'll send the next series. Specifically, No need to stop the VM and re-start it in case the SLA can't meet, just read upon RUNNING the estimated data length that will be required to complete STOP_COPY and use it. Yishai > - they need to send possible lots of data. > > this series only address the 1st set of problems. > > What they do: > - res_compatible parameter was not used anywhere, just add that > information to res_postcopy. > - Remove QEMUFILE parameter from save_live_pending > - Split save_live_pending into > * save_pending_estimate(): the pending state size without trying too hard > * save_pending_exact(): the real pending state size, it is called with the > guest stopped. > - Now save_pending_* don't need the threshold parameter > - HACK a way to stop the guest before moving there. > > ToDo: > - autoconverge test is broken, no real clue why, but it is possible that the > test > is wrong. > > - Make an artifact to be able to send massive amount of data in the save > state stage (probably more multifd channels). > > - Be able to not having to start the guest between cheking the state pending > size and migration_completion(). > > Please review. > > Thanks, Juan. > > Juan Quintela (7): > migration: Remove res_compatible parameter > migration: No save_live_pending() method uses the QEMUFile parameter > migration: Block migration comment or code is wrong > migration: Split save_live_pending() into state_pending_* > migration: Remove unused threshold_size parameter > migration: simplify migration_iteration_run() > migration: call qemu_savevm_state_pending_exact() with the guest > stopped > > docs/devel/migration.rst | 18 ++++++------ > docs/devel/vfio-migration.rst | 4 +-- > include/migration/register.h | 29 ++++++++++--------- > migration/savevm.h | 8 +++--- > hw/s390x/s390-stattrib.c | 11 ++++--- > hw/vfio/migration.c | 17 +++++------ > migration/block-dirty-bitmap.c | 14 ++++----- > migration/block.c | 17 ++++++----- > migration/migration.c | 52 ++++++++++++++++++++++------------ > migration/ram.c | 35 ++++++++++++++++------- > migration/savevm.c | 37 +++++++++++++++++------- > tests/qtest/migration-test.c | 3 +- > hw/vfio/trace-events | 2 +- > migration/trace-events | 7 +++-- > 14 files changed, 148 insertions(+), 106 deletions(-) > > -- > 2.37.2 >
