From 76208f7824d5139ac8d86140b0e01031b67638cc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Date: Wed, 12 Jul 2023 17:46:56 +0200 Subject: [PATCH 04/37] vfio/migration: Skip log_sync during migration SETUP state MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Cédric Le Goater RH-MergeRequest: 179: vfio: live migration support RH-Bugzilla: 2192818 RH-Acked-by: Eric Auger RH-Acked-by: Miroslav Rezanina RH-Commit: [2/28] 4c340992b472ac4627b57705f4e971f14bbb0846 (clegoate/qemu-kvm-c9s) Bugzilla: https://bugzilla.redhat.com/2192818 commit ff180c6bd7a8 Author: Avihai Horon Date: Mon Apr 3 16:00:00 2023 +0300 vfio/migration: Skip log_sync during migration SETUP state Currently, VFIO log_sync can be issued while migration is in SETUP state. However, doing this log_sync is at best redundant and at worst can fail. Redundant -- all RAM is marked dirty in migration SETUP state and is transferred only after migration is set to ACTIVE state, so doing log_sync during migration SETUP is pointless. Can fail -- there is a time window, between setting migration state to SETUP and starting dirty tracking by RAM save_live_setup handler, during which dirty tracking is still not started. Any VFIO log_sync call that is issued during this time window will fail. For example, this error can be triggered by migrating a VM when a GUI is active, which constantly calls log_sync. Fix it by skipping VFIO log_sync while migration is in SETUP state. Fixes: 758b96b61d5c ("vfio/migrate: Move switch of dirty tracking into vfio_memory_listener") Signed-off-by: Avihai Horon Link: https://lore.kernel.org/r/20230403130000.6422-1-avihaih@nvidia.com Signed-off-by: Alex Williamson Signed-off-by: Cédric Le Goater --- hw/vfio/common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 4d01ea3515..78358ede27 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -478,7 +478,8 @@ static bool vfio_devices_all_dirty_tracking(VFIOContainer *container) VFIODevice *vbasedev; MigrationState *ms = migrate_get_current(); - if (!migration_is_setup_or_active(ms->state)) { + if (ms->state != MIGRATION_STATUS_ACTIVE && + ms->state != MIGRATION_STATUS_DEVICE) { return false; } -- 2.39.3